diff --git a/base/runtime/internal.odin b/base/runtime/internal.odin index ff60cf547..a0bda9d40 100644 --- a/base/runtime/internal.odin +++ b/base/runtime/internal.odin @@ -118,16 +118,15 @@ mem_copy_non_overlapping :: proc "contextless" (dst, src: rawptr, len: int) -> r DEFAULT_ALIGNMENT :: 2*align_of(rawptr) mem_alloc_bytes :: #force_inline proc(size: int, alignment: int = DEFAULT_ALIGNMENT, allocator := context.allocator, loc := #caller_location) -> ([]byte, Allocator_Error) { - if size == 0 { - return nil, nil - } - if allocator.procedure == nil { + assert(is_power_of_two_int(alignment), "Alignment must be a power of two", loc) + if size == 0 || allocator.procedure == nil{ return nil, nil } return allocator.procedure(allocator.data, .Alloc, size, alignment, nil, 0, loc) } mem_alloc :: #force_inline proc(size: int, alignment: int = DEFAULT_ALIGNMENT, allocator := context.allocator, loc := #caller_location) -> ([]byte, Allocator_Error) { + assert(is_power_of_two_int(alignment), "Alignment must be a power of two", loc) if size == 0 || allocator.procedure == nil { return nil, nil } @@ -135,6 +134,7 @@ mem_alloc :: #force_inline proc(size: int, alignment: int = DEFAULT_ALIGNMENT, a } mem_alloc_non_zeroed :: #force_inline proc(size: int, alignment: int = DEFAULT_ALIGNMENT, allocator := context.allocator, loc := #caller_location) -> ([]byte, Allocator_Error) { + assert(is_power_of_two_int(alignment), "Alignment must be a power of two", loc) if size == 0 || allocator.procedure == nil { return nil, nil } @@ -174,6 +174,7 @@ mem_free_all :: #force_inline proc(allocator := context.allocator, loc := #calle } _mem_resize :: #force_inline proc(ptr: rawptr, old_size, new_size: int, alignment: int = DEFAULT_ALIGNMENT, allocator := context.allocator, should_zero: bool, loc := #caller_location) -> (data: []byte, err: Allocator_Error) { + assert(is_power_of_two_int(alignment), "Alignment must be a power of two", loc) if allocator.procedure == nil { return nil, nil } @@ -215,9 +216,11 @@ _mem_resize :: #force_inline proc(ptr: rawptr, old_size, new_size: int, alignmen } mem_resize :: proc(ptr: rawptr, old_size, new_size: int, alignment: int = DEFAULT_ALIGNMENT, allocator := context.allocator, loc := #caller_location) -> (data: []byte, err: Allocator_Error) { + assert(is_power_of_two_int(alignment), "Alignment must be a power of two", loc) return _mem_resize(ptr, old_size, new_size, alignment, allocator, true, loc) } non_zero_mem_resize :: proc(ptr: rawptr, old_size, new_size: int, alignment: int = DEFAULT_ALIGNMENT, allocator := context.allocator, loc := #caller_location) -> (data: []byte, err: Allocator_Error) { + assert(is_power_of_two_int(alignment), "Alignment must be a power of two", loc) return _mem_resize(ptr, old_size, new_size, alignment, allocator, false, loc) } diff --git a/core/mem/alloc.odin b/core/mem/alloc.odin index e51d971e1..fac58daaf 100644 --- a/core/mem/alloc.odin +++ b/core/mem/alloc.odin @@ -2,109 +2,711 @@ package mem import "base:runtime" -// NOTE(bill, 2019-12-31): These are defined in `package runtime` as they are used in the `context`. This is to prevent an import definition cycle. +//NOTE(bill, 2019-12-31): These are defined in `package runtime` as they are used in the `context`. This is to prevent an import definition cycle. + +/* +A request to allocator procedure. + +This type represents a type of allocation request made to an allocator +procedure. There is one allocator procedure per allocator, and this value is +used to discriminate between different functions of the allocator. + +The type is defined as follows: + + Allocator_Mode :: enum byte { + Alloc, + Alloc_Non_Zeroed, + Free, + Free_All, + Resize, + Resize_Non_Zeroed, + Query_Features, + } + +Depending on which value is used, the allocator procedure will perform different +functions: + +- `Alloc`: Allocates a memory region with a given `size` and `alignment`. +- `Alloc_Non_Zeroed`: Same as `Alloc` without explicit zero-initialization of + the memory region. +- `Free`: Free a memory region located at address `ptr` with a given `size`. +- `Free_All`: Free all memory allocated using this allocator. +- `Resize`: Resize a memory region located at address `old_ptr` with size + `old_size` to be `size` bytes in length and have the specified `alignment`, + in case a re-alllocation occurs. +- `Resize_Non_Zeroed`: Same as `Resize`, without explicit zero-initialization. +*/ Allocator_Mode :: runtime.Allocator_Mode -/* -Allocator_Mode :: enum byte { - Alloc, - Free, - Free_All, - Resize, - Query_Features, - Alloc_Non_Zeroed, - Resize_Non_Zeroed, -} -*/ +/* +A set of allocator features. + +This type represents values that contain a set of features an allocator has. +Currently the type is defined as follows: + + Allocator_Mode_Set :: distinct bit_set[Allocator_Mode]; +*/ Allocator_Mode_Set :: runtime.Allocator_Mode_Set -/* -Allocator_Mode_Set :: distinct bit_set[Allocator_Mode]; -*/ +/* +Allocator information. + +This type represents information about a given allocator at a specific point +in time. Currently the type is defined as follows: + + Allocator_Query_Info :: struct { + pointer: rawptr, + size: Maybe(int), + alignment: Maybe(int), + } + +- `pointer`: Pointer to a backing buffer. +- `size`: Size of the backing buffer. +- `alignment`: The allocator's alignment. + +If not applicable, any of these fields may be `nil`. +*/ Allocator_Query_Info :: runtime.Allocator_Query_Info -/* -Allocator_Query_Info :: struct { - pointer: rawptr, - size: Maybe(int), - alignment: Maybe(int), -} -*/ -Allocator_Error :: runtime.Allocator_Error /* -Allocator_Error :: enum byte { - None = 0, - Out_Of_Memory = 1, - Invalid_Pointer = 2, - Invalid_Argument = 3, - Mode_Not_Implemented = 4, -} +An allocation request error. + +This type represents error values the allocators may return upon requests. + + Allocator_Error :: enum byte { + None = 0, + Out_Of_Memory = 1, + Invalid_Pointer = 2, + Invalid_Argument = 3, + Mode_Not_Implemented = 4, + } + +The meaning of the errors is as follows: + +- `None`: No error. +- `Out_Of_Memory`: Either: + 1. The allocator has ran out of the backing buffer, or the requested + allocation size is too large to fit into a backing buffer. + 2. The operating system error during memory allocation. + 3. The backing allocator was used to allocate a new backing buffer and the + backing allocator returned Out_Of_Memory. +- `Invalid_Pointer`: The pointer referring to a memory region does not belong + to any of the allocators backing buffers or does not point to a valid start + of an allocation made in that allocator. +- `Invalid_Argument`: Can occur if one of the arguments makes it impossible to + satisfy a request (i.e. having alignment larger than the backing buffer + of the allocation). +- `Mode_Not_Implemented`: The allocator does not support the specified + operation. For example, an arena does not support freeing individual + allocations. +*/ +Allocator_Error :: runtime.Allocator_Error + +/* +The allocator procedure. + +This type represents allocation procedures. An allocation procedure is a single +procedure, implementing all allocator functions such as allocating the memory, +freeing the memory, etc. + +Currently the type is defined as follows: + + Allocator_Proc :: #type proc( + allocator_data: rawptr, + mode: Allocator_Mode, + size: int, + alignment: int, + old_memory: rawptr, + old_size: int, + location: Source_Code_Location = #caller_location, + ) -> ([]byte, Allocator_Error); + +The function of this procedure and the meaning of parameters depends on the +value of the `mode` parameter. For any operation the following constraints +apply: + +- The `alignment` must be a power of two. +- The `size` must be a positive integer. + +## 1. `.Alloc`, `.Alloc_Non_Zeroed` + +Allocates a memory region of size `size`, aligned on a boundary specified by +`alignment`. + +**Inputs**: +- `allocator_data`: Pointer to the allocator data. +- `mode`: `.Alloc` or `.Alloc_Non_Zeroed`. +- `size`: The desired size of the memory region. +- `alignment`: The desired alignmnet of the allocation. +- `old_memory`: Unused, should be `nil`. +- `old_size`: Unused, should be 0. + +**Returns**: +1. The memory region, if allocated successfully, or `nil` otherwise. +2. An error, if allocation failed. + +**Note**: The nil allocator may return `nil`, even if no error is returned. +Always check both the error and the allocated buffer. + +**Note**: The `.Alloc` mode is required to be implemented for an allocator +and can not return a `.Mode_Not_Implemented` error. + +## 2. `Free` + +Frees a memory region located at the address specified by `old_memory`. If the +allocator does not track sizes of allocations, the size should be specified in +the `old_size` parameter. + +**Inputs**: +- `allocator_data`: Pointer to the allocator data. +- `mode`: `.Free`. +- `size`: Unused, should be 0. +- `alignment`: Unused, should be 0. +- `old_memory`: Pointer to the memory region to free. +- `old_size`: The size of the memory region to free. This parameter is optional + if the allocator keeps track of the sizes of allocations. + +**Returns**: +1. `nil` +2. Error, if freeing failed. + +## 3. `Free_All` + +Frees all allocations, associated with the allocator, making it available for +further allocations using the same backing buffers. + +**Inputs**: +- `allocator_data`: Pointer to the allocator data. +- `mode`: `.Free_All`. +- `size`: Unused, should be 0. +- `alignment`: Unused, should be 0. +- `old_memory`: Unused, should be `nil`. +- `old_size`: Unused, should be `0`. + +**Returns**: +1. `nil`. +2. Error, if freeing failed. + +## 4. `Resize`, `Resize_Non_Zeroed` + +Resizes the memory region, of the size `old_size` located at the address +specified by `old_memory` to have the new size `size`. The slice of the new +memory region is returned from the procedure. The allocator may attempt to +keep the new memory region at the same address as the previous allocation, +however no such guarantee is made. Do not assume the new memory region will +be at the same address as the old memory region. + +If `old_memory` pointer is `nil`, this function acts just like `.Alloc` or +`.Alloc_Non_Zeroed`, using `size` and `alignment` to allocate a new memory +region. + +If `new_size` is `nil`, the procedure acts just like `.Free`, freeing the +memory region `old_size` bytes in length, located at the address specified by +`old_memory`. + +If the `old_memory` pointer is not aligned to the boundary specified by +`alignment`, the procedure relocates the buffer such that the reallocated +buffer is aligned to the boundary specified by `alignment`. + +**Inputs**: +- `allocator_data`: Pointer to the allocator data. +- `mode`: `.Resize` or `.Resize_All`. +- `size`: The desired new size of the memory region. +- `alignment`: The alignment of the new memory region, if its allocated +- `old_memory`: The pointer to the memory region to resize. +- `old_size`: The size of the memory region to resize. If the allocator + keeps track of the sizes of allocations, this parameter is optional. + +**Returns**: +1. The slice of the memory region after resize operation, if successfull, + `nil` otherwise. +2. An error, if the resize failed. + +**Note**: Some allocators may return `nil`, even if no error is returned. +Always check both the error and the allocated buffer. + +**Note**: if `old_size` is `0` and `old_memory` is `nil`, this operation is a +no-op, and should not return errors. */ Allocator_Proc :: runtime.Allocator_Proc -/* -Allocator_Proc :: #type proc(allocator_data: rawptr, mode: Allocator_Mode, - size, alignment: int, - old_memory: rawptr, old_size: int, location: Source_Code_Location = #caller_location) -> ([]byte, Allocator_Error); -*/ +/* +Allocator. + +This type represents generic interface for all allocators. Currently this type +is defined as follows: + + Allocator :: struct { + procedure: Allocator_Proc, + data: rawptr, + } + +- `procedure`: Pointer to the allocation procedure. +- `data`: Pointer to the allocator data. +*/ Allocator :: runtime.Allocator -/* -Allocator :: struct { - procedure: Allocator_Proc, - data: rawptr, -} -*/ +/* +Default alignment. + +This value is the default alignment for all platforms that is used, if the +alignment is not specified explicitly. +*/ DEFAULT_ALIGNMENT :: 2*align_of(rawptr) +/* +Default page size. + +This value is the default page size for the current platform. +*/ DEFAULT_PAGE_SIZE :: 64 * 1024 when ODIN_ARCH == .wasm32 || ODIN_ARCH == .wasm64p32 else 16 * 1024 when ODIN_OS == .Darwin && ODIN_ARCH == .arm64 else 4 * 1024 +/* +Allocate memory. + +This function allocates `size` bytes of memory, aligned to a boundary specified +by `alignment` using the allocator specified by `allocator`. + +If the `size` parameter is `0`, the operation is a no-op. + +**Inputs**: +- `size`: The desired size of the allocated memory region. +- `alignment`: The desired alignment of the allocated memory region. +- `allocator`: The allocator to allocate from. + +**Returns**: +1. Pointer to the allocated memory, or `nil` if allocation failed. +2. Error, if the allocation failed. + +**Errors**: +- `None`: If no error occurred. +- `Out_Of_Memory`: Occurs when the allocator runs out of space in any of its + backing buffers, the backing allocator has ran out of space, or an operating + system failure occurred. +- `Invalid_Argument`: If the supplied `size` is negative, alignment is not a + power of two. +*/ @(require_results) -alloc :: proc(size: int, alignment: int = DEFAULT_ALIGNMENT, allocator := context.allocator, loc := #caller_location) -> (rawptr, Allocator_Error) { +alloc :: proc( + size: int, + alignment: int = DEFAULT_ALIGNMENT, + allocator := context.allocator, + loc := #caller_location, +) -> (rawptr, Allocator_Error) { data, err := runtime.mem_alloc(size, alignment, allocator, loc) return raw_data(data), err } +/* +Allocate memory. + +This function allocates `size` bytes of memory, aligned to a boundary specified +by `alignment` using the allocator specified by `allocator`. + +**Inputs**: +- `size`: The desired size of the allocated memory region. +- `alignment`: The desired alignment of the allocated memory region. +- `allocator`: The allocator to allocate from. + +**Returns**: +1. Slice of the allocated memory region, or `nil` if allocation failed. +2. Error, if the allocation failed. + +**Errors**: +- `None`: If no error occurred. +- `Out_Of_Memory`: Occurs when the allocator runs out of space in any of its + backing buffers, the backing allocator has ran out of space, or an operating + system failure occurred. +- `Invalid_Argument`: If the supplied `size` is negative, alignment is not a + power of two. +*/ @(require_results) -alloc_bytes :: proc(size: int, alignment: int = DEFAULT_ALIGNMENT, allocator := context.allocator, loc := #caller_location) -> ([]byte, Allocator_Error) { +alloc_bytes :: proc( + size: int, + alignment: int = DEFAULT_ALIGNMENT, + allocator := context.allocator, + loc := #caller_location, +) -> ([]byte, Allocator_Error) { return runtime.mem_alloc(size, alignment, allocator, loc) } +/* +Allocate non-zeroed memory. + +This function allocates `size` bytes of memory, aligned to a boundary specified +by `alignment` using the allocator specified by `allocator`. This procedure +does not explicitly zero-initialize allocated memory region. + +**Inputs**: +- `size`: The desired size of the allocated memory region. +- `alignment`: The desired alignment of the allocated memory region. +- `allocator`: The allocator to allocate from. + +**Returns**: +1. Slice of the allocated memory region, or `nil` if allocation failed. +2. Error, if the allocation failed. + +**Errors**: +- `None`: If no error occurred. +- `Out_Of_Memory`: Occurs when the allocator runs out of space in any of its + backing buffers, the backing allocator has ran out of space, or an operating + system failure occurred. +- `Invalid_Argument`: If the supplied `size` is negative, alignment is not a + power of two. +*/ @(require_results) -alloc_bytes_non_zeroed :: proc(size: int, alignment: int = DEFAULT_ALIGNMENT, allocator := context.allocator, loc := #caller_location) -> ([]byte, Allocator_Error) { +alloc_bytes_non_zeroed :: proc( + size: int, + alignment: int = DEFAULT_ALIGNMENT, + allocator := context.allocator, + loc := #caller_location, +) -> ([]byte, Allocator_Error) { return runtime.mem_alloc_non_zeroed(size, alignment, allocator, loc) } -free :: proc(ptr: rawptr, allocator := context.allocator, loc := #caller_location) -> Allocator_Error { +/* +Free memory. + +This procedure frees memory region located at the address, specified by `ptr`, +allocated from the allocator specified by `allocator`. + +**Inputs**: +- `ptr`: Pointer to the memory region to free. +- `allocator`: The allocator to free to. + +**Returns**: +- The error, if freeing failed. + +**Errors**: +- `None`: When no error has occurred. +- `Invalid_Pointer`: The specified pointer is not owned by the specified allocator, + or does not point to a valid allocation. +- `Mode_Not_Implemented`: If the specified allocator does not support the `.Free` +mode. +*/ +free :: proc( + ptr: rawptr, + allocator := context.allocator, + loc := #caller_location, +) -> Allocator_Error { return runtime.mem_free(ptr, allocator, loc) } -free_with_size :: proc(ptr: rawptr, byte_count: int, allocator := context.allocator, loc := #caller_location) -> Allocator_Error { - return runtime.mem_free_with_size(ptr, byte_count, allocator, loc) +/* +Free a memory region. + +This procedure frees `size` bytes of memory region located at the address, +specified by `ptr`, allocated from the allocator specified by `allocator`. + +If the `size` parameter is `0`, this call is equivalent to `free()`. + +**Inputs**: +- `ptr`: Pointer to the memory region to free. +- `size`: The size of the memory region to free. +- `allocator`: The allocator to free to. + +**Returns**: +- The error, if freeing failed. + +**Errors**: +- `None`: When no error has occurred. +- `Invalid_Pointer`: The specified pointer is not owned by the specified allocator, + or does not point to a valid allocation. +- `Mode_Not_Implemented`: If the specified allocator does not support the `.Free` +mode. +*/ +free_with_size :: proc( + ptr: rawptr, + size: int, + allocator := context.allocator, + loc := #caller_location, +) -> Allocator_Error { + return runtime.mem_free_with_size(ptr, size, allocator, loc) } -free_bytes :: proc(bytes: []byte, allocator := context.allocator, loc := #caller_location) -> Allocator_Error { +/* +Free a memory region. + +This procedure frees memory region, specified by `bytes`, allocated from the +allocator specified by `allocator`. + +If the length of the specified slice is zero, the `.Invalid_Argument` error +is returned. + +**Inputs**: +- `bytes`: The memory region to free. +- `allocator`: The allocator to free to. + +**Returns**: +- The error, if freeing failed. + +**Errors**: +- `None`: When no error has occurred. +- `Invalid_Pointer`: The specified pointer is not owned by the specified allocator, + or does not point to a valid allocation. +- `Mode_Not_Implemented`: If the specified allocator does not support the `.Free` +mode. +*/ +free_bytes :: proc( + bytes: []byte, + allocator := context.allocator, + loc := #caller_location, +) -> Allocator_Error { return runtime.mem_free_bytes(bytes, allocator, loc) } +/* +Free all allocations. + +This procedure frees all allocations made on the allocator specified by +`allocator` to that allocator, making it available for further allocations. + +**Inputs**: +- `allocator`: The allocator to free to. + +**Errors**: +- `None`: When no error has occurred. +- `Mode_Not_Implemented`: If the specified allocator does not support the `.Free` +mode. +*/ free_all :: proc(allocator := context.allocator, loc := #caller_location) -> Allocator_Error { return runtime.mem_free_all(allocator, loc) } +/* +Resize a memory region. + +This procedure resizes a memory region, `old_size` bytes in size, located at +the address specified by `ptr`, such that it has a new size, specified by +`new_size` and and is aligned on a boundary specified by `alignment`. + +If the `ptr` parameter is `nil`, `resize()` acts just like `alloc()`, allocating +`new_size` bytes, aligned on a boundary specified by `alignment`. + +If the `new_size` parameter is `0`, `resize()` acts just like `free()`, freeing +the memory region `old_size` bytes in length, located at the address specified +by `ptr`. + +If the `old_memory` pointer is not aligned to the boundary specified by +`alignment`, the procedure relocates the buffer such that the reallocated +buffer is aligned to the boundary specified by `alignment`. + +**Inputs**: +- `ptr`: Pointer to the memory region to resize. +- `old_size`: Size of the memory region to resize. +- `new_size`: The desired size of the resized memory region. +- `alignment`: The desired alignment of the resized memory region. +- `allocator`: The owner of the memory region to resize. + +**Returns**: +1. The pointer to the resized memory region, if successfull, `nil` otherwise. +2. Error, if resize failed. + +**Errors**: +- `None`: No error. +- `Out_Of_Memory`: When the allocator's backing buffer or it's backing + allocator does not have enough space to fit in an allocation with the new + size, or an operating system failure occurs. +- `Invalid_Pointer`: The pointer referring to a memory region does not belong + to any of the allocators backing buffers or does not point to a valid start + of an allocation made in that allocator. +- `Invalid_Argument`: When `size` is negative, alignment is not a power of two, + or the `old_size` argument is incorrect. +- `Mode_Not_Implemented`: The allocator does not support the `.Realloc` mode. + +**Note**: if `old_size` is `0` and `old_memory` is `nil`, this operation is a +no-op, and should not return errors. +*/ @(require_results) -resize :: proc(ptr: rawptr, old_size, new_size: int, alignment: int = DEFAULT_ALIGNMENT, allocator := context.allocator, loc := #caller_location) -> (rawptr, Allocator_Error) { +resize :: proc( + ptr: rawptr, + old_size: int, + new_size: int, + alignment: int = DEFAULT_ALIGNMENT, + allocator := context.allocator, + loc := #caller_location, +) -> (rawptr, Allocator_Error) { data, err := runtime.mem_resize(ptr, old_size, new_size, alignment, allocator, loc) return raw_data(data), err } +/* +Resize a memory region without zero-initialization. + +This procedure resizes a memory region, `old_size` bytes in size, located at +the address specified by `ptr`, such that it has a new size, specified by +`new_size` and and is aligned on a boundary specified by `alignment`. + +If the `ptr` parameter is `nil`, `resize()` acts just like `alloc()`, allocating +`new_size` bytes, aligned on a boundary specified by `alignment`. + +If the `new_size` parameter is `0`, `resize()` acts just like `free()`, freeing +the memory region `old_size` bytes in length, located at the address specified +by `ptr`. + +If the `old_memory` pointer is not aligned to the boundary specified by +`alignment`, the procedure relocates the buffer such that the reallocated +buffer is aligned to the boundary specified by `alignment`. + +Unlike `resize()`, this procedure does not explicitly zero-initialize any new +memory. + +**Inputs**: +- `ptr`: Pointer to the memory region to resize. +- `old_size`: Size of the memory region to resize. +- `new_size`: The desired size of the resized memory region. +- `alignment`: The desired alignment of the resized memory region. +- `allocator`: The owner of the memory region to resize. + +**Returns**: +1. The pointer to the resized memory region, if successfull, `nil` otherwise. +2. Error, if resize failed. + +**Errors**: +- `None`: No error. +- `Out_Of_Memory`: When the allocator's backing buffer or it's backing + allocator does not have enough space to fit in an allocation with the new + size, or an operating system failure occurs. +- `Invalid_Pointer`: The pointer referring to a memory region does not belong + to any of the allocators backing buffers or does not point to a valid start + of an allocation made in that allocator. +- `Invalid_Argument`: When `size` is negative, alignment is not a power of two, + or the `old_size` argument is incorrect. +- `Mode_Not_Implemented`: The allocator does not support the `.Realloc` mode. + +**Note**: if `old_size` is `0` and `old_memory` is `nil`, this operation is a +no-op, and should not return errors. +*/ @(require_results) -resize_bytes :: proc(old_data: []byte, new_size: int, alignment: int = DEFAULT_ALIGNMENT, allocator := context.allocator, loc := #caller_location) -> ([]byte, Allocator_Error) { +resize_non_zeroed :: proc( + ptr: rawptr, + old_size: int, + new_size: int, + alignment: int = DEFAULT_ALIGNMENT, + allocator := context.allocator, + loc := #caller_location, +) -> (rawptr, Allocator_Error) { + data, err := runtime.non_zero_mem_resize(ptr, old_size, new_size, alignment, allocator, loc) + return raw_data(data), err +} + +/* +Resize a memory region. + +This procedure resizes a memory region, specified by `old_data`, such that it +has a new size, specified by `new_size` and and is aligned on a boundary +specified by `alignment`. + +If the `old_data` parameter is `nil`, `resize_bytes()` acts just like +`alloc_bytes()`, allocating `new_size` bytes, aligned on a boundary specified +by `alignment`. + +If the `new_size` parameter is `0`, `resize_bytes()` acts just like +`free_bytes()`, freeing the memory region specified by `old_data`. + +If the `old_memory` pointer is not aligned to the boundary specified by +`alignment`, the procedure relocates the buffer such that the reallocated +buffer is aligned to the boundary specified by `alignment`. + +**Inputs**: +- `old_data`: Pointer to the memory region to resize. +- `new_size`: The desired size of the resized memory region. +- `alignment`: The desired alignment of the resized memory region. +- `allocator`: The owner of the memory region to resize. + +**Returns**: +1. The resized memory region, if successfull, `nil` otherwise. +2. Error, if resize failed. + +**Errors**: +- `None`: No error. +- `Out_Of_Memory`: When the allocator's backing buffer or it's backing + allocator does not have enough space to fit in an allocation with the new + size, or an operating system failure occurs. +- `Invalid_Pointer`: The pointer referring to a memory region does not belong + to any of the allocators backing buffers or does not point to a valid start + of an allocation made in that allocator. +- `Invalid_Argument`: When `size` is negative, alignment is not a power of two, + or the `old_size` argument is incorrect. +- `Mode_Not_Implemented`: The allocator does not support the `.Realloc` mode. + +**Note**: if `old_size` is `0` and `old_memory` is `nil`, this operation is a +no-op, and should not return errors. +*/ +@(require_results) +resize_bytes :: proc( + old_data: []byte, + new_size: int, + alignment: int = DEFAULT_ALIGNMENT, + allocator := context.allocator, + loc := #caller_location, +) -> ([]byte, Allocator_Error) { return runtime.mem_resize(raw_data(old_data), len(old_data), new_size, alignment, allocator, loc) } +/* +Resize a memory region. + +This procedure resizes a memory region, specified by `old_data`, such that it +has a new size, specified by `new_size` and and is aligned on a boundary +specified by `alignment`. + +If the `old_data` parameter is `nil`, `resize_bytes()` acts just like +`alloc_bytes()`, allocating `new_size` bytes, aligned on a boundary specified +by `alignment`. + +If the `new_size` parameter is `0`, `resize_bytes()` acts just like +`free_bytes()`, freeing the memory region specified by `old_data`. + +If the `old_memory` pointer is not aligned to the boundary specified by +`alignment`, the procedure relocates the buffer such that the reallocated +buffer is aligned to the boundary specified by `alignment`. + +Unlike `resize_bytes()`, this procedure does not explicitly zero-initialize +any new memory. + +**Inputs**: +- `old_data`: Pointer to the memory region to resize. +- `new_size`: The desired size of the resized memory region. +- `alignment`: The desired alignment of the resized memory region. +- `allocator`: The owner of the memory region to resize. + +**Returns**: +1. The resized memory region, if successfull, `nil` otherwise. +2. Error, if resize failed. + +**Errors**: +- `None`: No error. +- `Out_Of_Memory`: When the allocator's backing buffer or it's backing + allocator does not have enough space to fit in an allocation with the new + size, or an operating system failure occurs. +- `Invalid_Pointer`: The pointer referring to a memory region does not belong + to any of the allocators backing buffers or does not point to a valid start + of an allocation made in that allocator. +- `Invalid_Argument`: When `size` is negative, alignment is not a power of two, + or the `old_size` argument is incorrect. +- `Mode_Not_Implemented`: The allocator does not support the `.Realloc` mode. + +**Note**: if `old_size` is `0` and `old_memory` is `nil`, this operation is a +no-op, and should not return errors. +*/ +@(require_results) +resize_bytes_non_zeroed :: proc( + old_data: []byte, + new_size: int, + alignment: int = DEFAULT_ALIGNMENT, + allocator := context.allocator, + loc := #caller_location, +) -> ([]byte, Allocator_Error) { + return runtime.non_zero_mem_resize(raw_data(old_data), len(old_data), new_size, alignment, allocator, loc) +} + +/* +Query allocator features. +*/ @(require_results) query_features :: proc(allocator: Allocator, loc := #caller_location) -> (set: Allocator_Mode_Set) { if allocator.procedure != nil { @@ -114,8 +716,15 @@ query_features :: proc(allocator: Allocator, loc := #caller_location) -> (set: A return nil } +/* +Query allocator information. +*/ @(require_results) -query_info :: proc(pointer: rawptr, allocator: Allocator, loc := #caller_location) -> (props: Allocator_Query_Info) { +query_info :: proc( + pointer: rawptr, + allocator: Allocator, + loc := #caller_location, +) -> (props: Allocator_Query_Info) { props.pointer = pointer if allocator.procedure != nil { allocator.procedure(allocator.data, .Query_Info, 0, 0, &props, 0, loc) @@ -123,25 +732,62 @@ query_info :: proc(pointer: rawptr, allocator: Allocator, loc := #caller_locatio return } - - -delete_string :: proc(str: string, allocator := context.allocator, loc := #caller_location) -> Allocator_Error { +/* +Free a string. +*/ +delete_string :: proc( + str: string, + allocator := context.allocator, + loc := #caller_location, +) -> Allocator_Error { return runtime.delete_string(str, allocator, loc) } -delete_cstring :: proc(str: cstring, allocator := context.allocator, loc := #caller_location) -> Allocator_Error { + +/* +Free a cstring. +*/ +delete_cstring :: proc( + str: cstring, + allocator := context.allocator, + loc := #caller_location, +) -> Allocator_Error { return runtime.delete_cstring(str, allocator, loc) } -delete_dynamic_array :: proc(array: $T/[dynamic]$E, loc := #caller_location) -> Allocator_Error { + +/* +Free a dynamic array. +*/ +delete_dynamic_array :: proc( + array: $T/[dynamic]$E, + loc := #caller_location, +) -> Allocator_Error { return runtime.delete_dynamic_array(array, loc) } -delete_slice :: proc(array: $T/[]$E, allocator := context.allocator, loc := #caller_location) -> Allocator_Error { + +/* +Free a slice. +*/ +delete_slice :: proc( + array: $T/[]$E, + allocator := context.allocator, + loc := #caller_location, +) -> Allocator_Error { return runtime.delete_slice(array, allocator, loc) } -delete_map :: proc(m: $T/map[$K]$V, loc := #caller_location) -> Allocator_Error { + +/* +Free a map. +*/ +delete_map :: proc( + m: $T/map[$K]$V, + loc := #caller_location, +) -> Allocator_Error { return runtime.delete_map(m, loc) } - +/* +Free. +*/ delete :: proc{ delete_string, delete_cstring, @@ -150,49 +796,177 @@ delete :: proc{ delete_map, } +/* +Allocate a new object. +This procedure allocates a new object of type `T` using an allocator specified +by `allocator`, and returns a pointer to the allocated object, if allocated +successfully, or `nil` otherwise. +*/ @(require_results) -new :: proc($T: typeid, allocator := context.allocator, loc := #caller_location) -> (^T, Allocator_Error) { +new :: proc( + $T: typeid, + allocator := context.allocator, + loc := #caller_location, +) -> (^T, Allocator_Error) { return new_aligned(T, align_of(T), allocator, loc) } + +/* +Allocate a new object with alignment. + +This procedure allocates a new object of type `T` using an allocator specified +by `allocator`, and returns a pointer, aligned on a boundary specified by +`alignment` to the allocated object, if allocated successfully, or `nil` +otherwise. +*/ @(require_results) -new_aligned :: proc($T: typeid, alignment: int, allocator := context.allocator, loc := #caller_location) -> (t: ^T, err: Allocator_Error) { +new_aligned :: proc( + $T: typeid, + alignment: int, + allocator := context.allocator, + loc := #caller_location, +) -> (t: ^T, err: Allocator_Error) { return runtime.new_aligned(T, alignment, allocator, loc) } + +/* +Allocate a new object and initialize it with a value. + +This procedure allocates a new object of type `T` using an allocator specified +by `allocator`, and returns a pointer, aligned on a boundary specified by +`alignment` to the allocated object, if allocated successfully, or `nil` +otherwise. The allocated object is initialized with `data`. +*/ @(require_results) -new_clone :: proc(data: $T, allocator := context.allocator, loc := #caller_location) -> (t: ^T, err: Allocator_Error) { +new_clone :: proc( + data: $T, + allocator := context.allocator, + loc := #caller_location, +) -> (t: ^T, err: Allocator_Error) { return runtime.new_clone(data, allocator, loc) } +/* +Allocate a new slice with alignment. + +This procedure allocates a new slice of type `T` with length `len`, aligned +on a boundary specified by `alignment` from an allocator specified by +`allocator`, and returns the allocated slice. +*/ @(require_results) -make_aligned :: proc($T: typeid/[]$E, #any_int len: int, alignment: int, allocator := context.allocator, loc := #caller_location) -> (slice: T, err: Allocator_Error) { +make_aligned :: proc( + $T: typeid/[]$E, + #any_int len: int, + alignment: int, + allocator := context.allocator, + loc := #caller_location, +) -> (slice: T, err: Allocator_Error) { return runtime.make_aligned(T, len, alignment, allocator, loc) } + +/* +Allocate a new slice. + +This procedure allocates a new slice of type `T` with length `len`, from an +allocator specified by `allocator`, and returns the allocated slice. +*/ @(require_results) -make_slice :: proc($T: typeid/[]$E, #any_int len: int, allocator := context.allocator, loc := #caller_location) -> (T, Allocator_Error) { +make_slice :: proc( + $T: typeid/[]$E, + #any_int len: int, + allocator := context.allocator, + loc := #caller_location, +) -> (T, Allocator_Error) { return runtime.make_slice(T, len, allocator, loc) } + +/* +Allocate a dynamic array. + +This procedure creates a dynamic array of type `T`, with `allocator` as its +backing allocator, and initial length and capacity of `0`. +*/ @(require_results) -make_dynamic_array :: proc($T: typeid/[dynamic]$E, allocator := context.allocator, loc := #caller_location) -> (T, Allocator_Error) { +make_dynamic_array :: proc( + $T: typeid/[dynamic]$E, + allocator := context.allocator, + loc := #caller_location, +) -> (T, Allocator_Error) { return runtime.make_dynamic_array(T, allocator, loc) } + +/* +Allocate a dynamic array with initial length. + +This procedure creates a dynamic array of type `T`, with `allocator` as its +backing allocator, and initial capacity of `0`, and initial length specified by +`len`. +*/ @(require_results) -make_dynamic_array_len :: proc($T: typeid/[dynamic]$E, #any_int len: int, allocator := context.allocator, loc := #caller_location) -> (T, Allocator_Error) { +make_dynamic_array_len :: proc( + $T: typeid/[dynamic]$E, + #any_int len: int, + allocator := context.allocator, + loc := #caller_location, +) -> (T, Allocator_Error) { return runtime.make_dynamic_array_len_cap(T, len, len, allocator, loc) } + +/* +Allocate a dynamic array with initial length and capacity. + +This procedure creates a dynamic array of type `T`, with `allocator` as its +backing allocator, and initial capacity specified by `cap`, and initial length +specified by `len`. +*/ @(require_results) -make_dynamic_array_len_cap :: proc($T: typeid/[dynamic]$E, #any_int len: int, #any_int cap: int, allocator := context.allocator, loc := #caller_location) -> (array: T, err: Allocator_Error) { +make_dynamic_array_len_cap :: proc( + $T: typeid/[dynamic]$E, + #any_int len: int, + #any_int cap: int, + allocator := context.allocator, + loc := #caller_location, +) -> (array: T, err: Allocator_Error) { return runtime.make_dynamic_array_len_cap(T, len, cap, allocator, loc) } + +/* +Allocate a map. + +This procedure creates a map of type `T` with initial capacity specified by +`cap`, that is using an allocator specified by `allocator` as its backing +allocator. +*/ @(require_results) -make_map :: proc($T: typeid/map[$K]$E, #any_int cap: int = 1< (m: T, err: Allocator_Error) { +make_map :: proc( + $T: typeid/map[$K]$E, + #any_int cap: int = 1< (m: T, err: Allocator_Error) { return runtime.make_map(T, cap, allocator, loc) } + +/* +Allocate a multi pointer. + +This procedure allocates a multipointer of type `T` pointing to `len` elements, +from an allocator specified by `allocator`. +*/ @(require_results) -make_multi_pointer :: proc($T: typeid/[^]$E, #any_int len: int, allocator := context.allocator, loc := #caller_location) -> (mp: T, err: Allocator_Error) { +make_multi_pointer :: proc( + $T: typeid/[^]$E, + #any_int len: int, + allocator := context.allocator, + loc := #caller_location +) -> (mp: T, err: Allocator_Error) { return runtime.make_multi_pointer(T, len, allocator, loc) } +/* +Allocate. +*/ make :: proc{ make_slice, make_dynamic_array, @@ -202,26 +976,112 @@ make :: proc{ make_multi_pointer, } +/* +Default resize procedure. +When allocator does not support resize operation, but supports `.Alloc` and +`.Free`, this procedure is used to implement allocator's default behavior on +resize. + +The behavior of the function is as follows: + +- If `new_size` is `0`, the function acts like `free()`, freeing the memory + region of `old_size` bytes located at `old_memory`. +- If `old_memory` is `nil`, the function acts like `alloc()`, allocating + `new_size` bytes of memory aligned on a boundary specified by `alignment`. +- Otherwise, a new memory region of size `new_size` is allocated, then the + data from the old memory region is copied and the old memory region is + freed. +*/ @(require_results) -default_resize_align :: proc(old_memory: rawptr, old_size, new_size, alignment: int, allocator := context.allocator, loc := #caller_location) -> (res: rawptr, err: Allocator_Error) { +default_resize_align :: proc( + old_memory: rawptr, + old_size: int, + new_size: int, + alignment: int, + allocator := context.allocator, + loc := #caller_location, +) -> (res: rawptr, err: Allocator_Error) { data: []byte - data, err = default_resize_bytes_align(([^]byte)(old_memory)[:old_size], new_size, alignment, allocator, loc) + data, err = default_resize_bytes_align( + ([^]byte) (old_memory)[:old_size], + new_size, + alignment, + allocator, + loc, + ) res = raw_data(data) return } +/* +Default resize procedure. + +When allocator does not support resize operation, but supports +`.Alloc_Non_Zeroed` and `.Free`, this procedure is used to implement allocator's +default behavior on resize. + +Unlike `default_resize_align` no new memory is being explicitly +zero-initialized. + +The behavior of the function is as follows: + +- If `new_size` is `0`, the function acts like `free()`, freeing the memory + region of `old_size` bytes located at `old_memory`. +- If `old_memory` is `nil`, the function acts like `alloc()`, allocating + `new_size` bytes of memory aligned on a boundary specified by `alignment`. +- Otherwise, a new memory region of size `new_size` is allocated, then the + data from the old memory region is copied and the old memory region is + freed. +*/ @(require_results) -default_resize_bytes_align_non_zeroed :: proc(old_data: []byte, new_size, alignment: int, allocator := context.allocator, loc := #caller_location) -> ([]byte, Allocator_Error) { +default_resize_bytes_align_non_zeroed :: proc( + old_data: []byte, + new_size: int, + alignment: int, + allocator := context.allocator, + loc := #caller_location, +) -> ([]byte, Allocator_Error) { return _default_resize_bytes_align(old_data, new_size, alignment, false, allocator, loc) } + +/* +Default resize procedure. + +When allocator does not support resize operation, but supports `.Alloc` and +`.Free`, this procedure is used to implement allocator's default behavior on +resize. + +The behavior of the function is as follows: + +- If `new_size` is `0`, the function acts like `free()`, freeing the memory + region specified by `old_data`. +- If `old_data` is `nil`, the function acts like `alloc()`, allocating + `new_size` bytes of memory aligned on a boundary specified by `alignment`. +- Otherwise, a new memory region of size `new_size` is allocated, then the + data from the old memory region is copied and the old memory region is + freed. +*/ @(require_results) -default_resize_bytes_align :: proc(old_data: []byte, new_size, alignment: int, allocator := context.allocator, loc := #caller_location) -> ([]byte, Allocator_Error) { +default_resize_bytes_align :: proc( + old_data: []byte, + new_size: int, + alignment: int, + allocator := context.allocator, + loc := #caller_location, +) -> ([]byte, Allocator_Error) { return _default_resize_bytes_align(old_data, new_size, alignment, true, allocator, loc) } @(require_results) -_default_resize_bytes_align :: #force_inline proc(old_data: []byte, new_size, alignment: int, should_zero: bool, allocator := context.allocator, loc := #caller_location) -> ([]byte, Allocator_Error) { +_default_resize_bytes_align :: #force_inline proc( + old_data: []byte, + new_size: int, + alignment: int, + should_zero: bool, + allocator := context.allocator, + loc := #caller_location, +) -> ([]byte, Allocator_Error) { old_memory := raw_data(old_data) old_size := len(old_data) if old_memory == nil { @@ -231,16 +1091,13 @@ _default_resize_bytes_align :: #force_inline proc(old_data: []byte, new_size, al return alloc_bytes_non_zeroed(new_size, alignment, allocator, loc) } } - if new_size == 0 { err := free_bytes(old_data, allocator, loc) return nil, err } - - if new_size == old_size { + if new_size == old_size && is_aligned(old_memory, alignment) { return old_data, .None } - new_memory : []byte err : Allocator_Error if should_zero { @@ -251,7 +1108,6 @@ _default_resize_bytes_align :: #force_inline proc(old_data: []byte, new_size, al if new_memory == nil || err != nil { return nil, err } - runtime.copy(new_memory, old_data) free_bytes(old_data, allocator, loc) return new_memory, err diff --git a/core/mem/allocators.odin b/core/mem/allocators.odin index a5b93ad05..4b5efbacb 100644 --- a/core/mem/allocators.odin +++ b/core/mem/allocators.odin @@ -3,12 +3,14 @@ package mem import "base:intrinsics" import "base:runtime" -nil_allocator_proc :: proc(allocator_data: rawptr, mode: Allocator_Mode, - size, alignment: int, - old_memory: rawptr, old_size: int, loc := #caller_location) -> ([]byte, Allocator_Error) { - return nil, nil -} +/* +Nil allocator. +The `nil` allocator returns `nil` on every allocation attempt. This type of +allocator can be used in scenarios where memory doesn't need to be allocated, +but an attempt to allocate memory is not an error. +*/ +@(require_results) nil_allocator :: proc() -> Allocator { return Allocator{ procedure = nil_allocator_proc, @@ -16,803 +18,41 @@ nil_allocator :: proc() -> Allocator { } } -// Custom allocators - -Arena :: struct { - data: []byte, - offset: int, - peak_used: int, - temp_count: int, -} - -Arena_Temp_Memory :: struct { - arena: ^Arena, - prev_offset: int, -} - - -arena_init :: proc(a: ^Arena, data: []byte) { - a.data = data - a.offset = 0 - a.peak_used = 0 - a.temp_count = 0 -} - -@(deprecated="prefer 'mem.arena_init'") -init_arena :: proc(a: ^Arena, data: []byte) { - a.data = data - a.offset = 0 - a.peak_used = 0 - a.temp_count = 0 -} - -@(require_results) -arena_allocator :: proc(arena: ^Arena) -> Allocator { - return Allocator{ - procedure = arena_allocator_proc, - data = arena, - } -} - -arena_allocator_proc :: proc(allocator_data: rawptr, mode: Allocator_Mode, - size, alignment: int, - old_memory: rawptr, old_size: int, location := #caller_location) -> ([]byte, Allocator_Error) { - arena := cast(^Arena)allocator_data - - switch mode { - case .Alloc, .Alloc_Non_Zeroed: - #no_bounds_check end := &arena.data[arena.offset] - - ptr := align_forward(end, uintptr(alignment)) - - total_size := size + ptr_sub((^byte)(ptr), (^byte)(end)) - - if arena.offset + total_size > len(arena.data) { - return nil, .Out_Of_Memory - } - - arena.offset += total_size - arena.peak_used = max(arena.peak_used, arena.offset) - if mode != .Alloc_Non_Zeroed { - zero(ptr, size) - } - return byte_slice(ptr, size), nil - - case .Free: - return nil, .Mode_Not_Implemented - - case .Free_All: - arena.offset = 0 - - case .Resize: - return default_resize_bytes_align(byte_slice(old_memory, old_size), size, alignment, arena_allocator(arena)) - - case .Resize_Non_Zeroed: - return default_resize_bytes_align_non_zeroed(byte_slice(old_memory, old_size), size, alignment, arena_allocator(arena)) - - case .Query_Features: - set := (^Allocator_Mode_Set)(old_memory) - if set != nil { - set^ = {.Alloc, .Alloc_Non_Zeroed, .Free_All, .Resize, .Resize_Non_Zeroed, .Query_Features} - } - return nil, nil - - case .Query_Info: - return nil, .Mode_Not_Implemented - } - - return nil, nil -} - -@(require_results) -begin_arena_temp_memory :: proc(a: ^Arena) -> Arena_Temp_Memory { - tmp: Arena_Temp_Memory - tmp.arena = a - tmp.prev_offset = a.offset - a.temp_count += 1 - return tmp -} - -end_arena_temp_memory :: proc(tmp: Arena_Temp_Memory) { - assert(tmp.arena.offset >= tmp.prev_offset) - assert(tmp.arena.temp_count > 0) - tmp.arena.offset = tmp.prev_offset - tmp.arena.temp_count -= 1 -} - - - -Scratch_Allocator :: struct { - data: []byte, - curr_offset: int, - prev_allocation: rawptr, - backup_allocator: Allocator, - leaked_allocations: [dynamic][]byte, -} - -scratch_allocator_init :: proc(s: ^Scratch_Allocator, size: int, backup_allocator := context.allocator) -> Allocator_Error { - s.data = make_aligned([]byte, size, 2*align_of(rawptr), backup_allocator) or_return - s.curr_offset = 0 - s.prev_allocation = nil - s.backup_allocator = backup_allocator - s.leaked_allocations.allocator = backup_allocator - return nil -} - -scratch_allocator_destroy :: proc(s: ^Scratch_Allocator) { - if s == nil { - return - } - for ptr in s.leaked_allocations { - free_bytes(ptr, s.backup_allocator) - } - delete(s.leaked_allocations) - delete(s.data, s.backup_allocator) - s^ = {} -} - -scratch_allocator_proc :: proc(allocator_data: rawptr, mode: Allocator_Mode, - size, alignment: int, - old_memory: rawptr, old_size: int, loc := #caller_location) -> ([]byte, Allocator_Error) { - - s := (^Scratch_Allocator)(allocator_data) - - if s.data == nil { - DEFAULT_BACKING_SIZE :: 4 * Megabyte - if !(context.allocator.procedure != scratch_allocator_proc && - context.allocator.data != allocator_data) { - panic("cyclic initialization of the scratch allocator with itself") - } - scratch_allocator_init(s, DEFAULT_BACKING_SIZE) - } - - size := size - - switch mode { - case .Alloc, .Alloc_Non_Zeroed: - size = align_forward_int(size, alignment) - - switch { - case s.curr_offset+size <= len(s.data): - start := uintptr(raw_data(s.data)) - ptr := start + uintptr(s.curr_offset) - ptr = align_forward_uintptr(ptr, uintptr(alignment)) - if mode != .Alloc_Non_Zeroed { - zero(rawptr(ptr), size) - } - - s.prev_allocation = rawptr(ptr) - offset := int(ptr - start) - s.curr_offset = offset + size - return byte_slice(rawptr(ptr), size), nil - - case size <= len(s.data): - start := uintptr(raw_data(s.data)) - ptr := align_forward_uintptr(start, uintptr(alignment)) - if mode != .Alloc_Non_Zeroed { - zero(rawptr(ptr), size) - } - - s.prev_allocation = rawptr(ptr) - offset := int(ptr - start) - s.curr_offset = offset + size - return byte_slice(rawptr(ptr), size), nil - } - a := s.backup_allocator - if a.procedure == nil { - a = context.allocator - s.backup_allocator = a - } - - ptr, err := alloc_bytes(size, alignment, a, loc) - if err != nil { - return ptr, err - } - if s.leaked_allocations == nil { - s.leaked_allocations, err = make([dynamic][]byte, a) - } - append(&s.leaked_allocations, ptr) - - if logger := context.logger; logger.lowest_level <= .Warning { - if logger.procedure != nil { - logger.procedure(logger.data, .Warning, "mem.Scratch_Allocator resorted to backup_allocator" , logger.options, loc) - } - } - - return ptr, err - - case .Free: - if old_memory == nil { - return nil, nil - } - start := uintptr(raw_data(s.data)) - end := start + uintptr(len(s.data)) - old_ptr := uintptr(old_memory) - - if s.prev_allocation == old_memory { - s.curr_offset = int(uintptr(s.prev_allocation) - start) - s.prev_allocation = nil - return nil, nil - } - - if start <= old_ptr && old_ptr < end { - // NOTE(bill): Cannot free this pointer but it is valid - return nil, nil - } - - if len(s.leaked_allocations) != 0 { - for data, i in s.leaked_allocations { - ptr := raw_data(data) - if ptr == old_memory { - free_bytes(data, s.backup_allocator) - ordered_remove(&s.leaked_allocations, i) - return nil, nil - } - } - } - return nil, .Invalid_Pointer - // panic("invalid pointer passed to default_temp_allocator"); - - case .Free_All: - s.curr_offset = 0 - s.prev_allocation = nil - for ptr in s.leaked_allocations { - free_bytes(ptr, s.backup_allocator) - } - clear(&s.leaked_allocations) - - case .Resize, .Resize_Non_Zeroed: - begin := uintptr(raw_data(s.data)) - end := begin + uintptr(len(s.data)) - old_ptr := uintptr(old_memory) - if begin <= old_ptr && old_ptr < end && old_ptr+uintptr(size) < end { - s.curr_offset = int(old_ptr-begin)+size - return byte_slice(old_memory, size), nil - } - data, err := scratch_allocator_proc(allocator_data, .Alloc, size, alignment, old_memory, old_size, loc) - if err != nil { - return data, err - } - runtime.copy(data, byte_slice(old_memory, old_size)) - _, err = scratch_allocator_proc(allocator_data, .Free, 0, alignment, old_memory, old_size, loc) - return data, err - - case .Query_Features: - set := (^Allocator_Mode_Set)(old_memory) - if set != nil { - set^ = {.Alloc, .Alloc_Non_Zeroed, .Free, .Free_All, .Resize, .Resize_Non_Zeroed, .Query_Features} - } - return nil, nil - - case .Query_Info: - return nil, .Mode_Not_Implemented - } - - return nil, nil -} - -@(require_results) -scratch_allocator :: proc(allocator: ^Scratch_Allocator) -> Allocator { - return Allocator{ - procedure = scratch_allocator_proc, - data = allocator, - } -} - - - - - -Stack_Allocation_Header :: struct { - prev_offset: int, - padding: int, -} - -// Stack is a stack-like allocator which has a strict memory freeing order -Stack :: struct { - data: []byte, - prev_offset: int, - curr_offset: int, - peak_used: int, -} - -stack_init :: proc(s: ^Stack, data: []byte) { - s.data = data - s.prev_offset = 0 - s.curr_offset = 0 - s.peak_used = 0 -} - -@(deprecated="prefer 'mem.stack_init'") -init_stack :: proc(s: ^Stack, data: []byte) { - s.data = data - s.prev_offset = 0 - s.curr_offset = 0 - s.peak_used = 0 -} - -@(require_results) -stack_allocator :: proc(stack: ^Stack) -> Allocator { - return Allocator{ - procedure = stack_allocator_proc, - data = stack, - } -} - - -stack_allocator_proc :: proc(allocator_data: rawptr, mode: Allocator_Mode, - size, alignment: int, - old_memory: rawptr, old_size: int, location := #caller_location) -> ([]byte, Allocator_Error) { - s := cast(^Stack)allocator_data - - if s.data == nil { - return nil, .Invalid_Argument - } - - raw_alloc :: proc(s: ^Stack, size, alignment: int, zero_memory: bool) -> ([]byte, Allocator_Error) { - curr_addr := uintptr(raw_data(s.data)) + uintptr(s.curr_offset) - padding := calc_padding_with_header(curr_addr, uintptr(alignment), size_of(Stack_Allocation_Header)) - if s.curr_offset + padding + size > len(s.data) { - return nil, .Out_Of_Memory - } - s.prev_offset = s.curr_offset - s.curr_offset += padding - - next_addr := curr_addr + uintptr(padding) - header := (^Stack_Allocation_Header)(next_addr - size_of(Stack_Allocation_Header)) - header.padding = padding - header.prev_offset = s.prev_offset - - s.curr_offset += size - - s.peak_used = max(s.peak_used, s.curr_offset) - - if zero_memory { - zero(rawptr(next_addr), size) - } - return byte_slice(rawptr(next_addr), size), nil - } - - switch mode { - case .Alloc, .Alloc_Non_Zeroed: - return raw_alloc(s, size, alignment, mode == .Alloc) - case .Free: - if old_memory == nil { - return nil, nil - } - start := uintptr(raw_data(s.data)) - end := start + uintptr(len(s.data)) - curr_addr := uintptr(old_memory) - - if !(start <= curr_addr && curr_addr < end) { - panic("Out of bounds memory address passed to stack allocator (free)") - } - - if curr_addr >= start+uintptr(s.curr_offset) { - // NOTE(bill): Allow double frees - return nil, nil - } - - header := (^Stack_Allocation_Header)(curr_addr - size_of(Stack_Allocation_Header)) - old_offset := int(curr_addr - uintptr(header.padding) - uintptr(raw_data(s.data))) - - if old_offset != header.prev_offset { - // panic("Out of order stack allocator free"); - return nil, .Invalid_Pointer - } - - s.curr_offset = old_offset - s.prev_offset = header.prev_offset - - case .Free_All: - s.prev_offset = 0 - s.curr_offset = 0 - - case .Resize, .Resize_Non_Zeroed: - if old_memory == nil { - return raw_alloc(s, size, alignment, mode == .Resize) - } - if size == 0 { - return nil, nil - } - - start := uintptr(raw_data(s.data)) - end := start + uintptr(len(s.data)) - curr_addr := uintptr(old_memory) - if !(start <= curr_addr && curr_addr < end) { - panic("Out of bounds memory address passed to stack allocator (resize)") - } - - if curr_addr >= start+uintptr(s.curr_offset) { - // NOTE(bill): Allow double frees - return nil, nil - } - - if old_size == size { - return byte_slice(old_memory, size), nil - } - - header := (^Stack_Allocation_Header)(curr_addr - size_of(Stack_Allocation_Header)) - old_offset := int(curr_addr - uintptr(header.padding) - uintptr(raw_data(s.data))) - - if old_offset != header.prev_offset { - data, err := raw_alloc(s, size, alignment, mode == .Resize) - if err == nil { - runtime.copy(data, byte_slice(old_memory, old_size)) - } - return data, err - } - - old_memory_size := uintptr(s.curr_offset) - (curr_addr - start) - assert(old_memory_size == uintptr(old_size)) - - diff := size - old_size - s.curr_offset += diff // works for smaller sizes too - if diff > 0 { - zero(rawptr(curr_addr + uintptr(diff)), diff) - } - - return byte_slice(old_memory, size), nil - - case .Query_Features: - set := (^Allocator_Mode_Set)(old_memory) - if set != nil { - set^ = {.Alloc, .Alloc_Non_Zeroed, .Free, .Free_All, .Resize, .Resize_Non_Zeroed, .Query_Features} - } - return nil, nil - case .Query_Info: - return nil, .Mode_Not_Implemented - } - +nil_allocator_proc :: proc( + allocator_data: rawptr, + mode: Allocator_Mode, + size, alignment: int, + old_memory: rawptr, + old_size: int, + loc := #caller_location, +) -> ([]byte, Allocator_Error) { return nil, nil } +/* +Panic allocator. - - - - -Small_Stack_Allocation_Header :: struct { - padding: u8, -} - -// Small_Stack is a stack-like allocator which uses the smallest possible header but at the cost of non-strict memory freeing order -Small_Stack :: struct { - data: []byte, - offset: int, - peak_used: int, -} - -small_stack_init :: proc(s: ^Small_Stack, data: []byte) { - s.data = data - s.offset = 0 - s.peak_used = 0 -} - -@(deprecated="prefer 'small_stack_init'") -init_small_stack :: proc(s: ^Small_Stack, data: []byte) { - s.data = data - s.offset = 0 - s.peak_used = 0 -} - +The panic allocator is a type of allocator that panics on any allocation +attempt. This type of allocator can be used in scenarios where memory should +not be allocated, and an attempt to allocate memory is an error. +*/ @(require_results) -small_stack_allocator :: proc(stack: ^Small_Stack) -> Allocator { +panic_allocator :: proc() -> Allocator { return Allocator{ - procedure = small_stack_allocator_proc, - data = stack, + procedure = panic_allocator_proc, + data = nil, } } -small_stack_allocator_proc :: proc(allocator_data: rawptr, mode: Allocator_Mode, - size, alignment: int, - old_memory: rawptr, old_size: int, location := #caller_location) -> ([]byte, Allocator_Error) { - s := cast(^Small_Stack)allocator_data - - if s.data == nil { - return nil, .Invalid_Argument - } - - align := clamp(alignment, 1, 8*size_of(Stack_Allocation_Header{}.padding)/2) - - raw_alloc :: proc(s: ^Small_Stack, size, alignment: int, zero_memory: bool) -> ([]byte, Allocator_Error) { - curr_addr := uintptr(raw_data(s.data)) + uintptr(s.offset) - padding := calc_padding_with_header(curr_addr, uintptr(alignment), size_of(Small_Stack_Allocation_Header)) - if s.offset + padding + size > len(s.data) { - return nil, .Out_Of_Memory - } - s.offset += padding - - next_addr := curr_addr + uintptr(padding) - header := (^Small_Stack_Allocation_Header)(next_addr - size_of(Small_Stack_Allocation_Header)) - header.padding = auto_cast padding - - s.offset += size - - s.peak_used = max(s.peak_used, s.offset) - - if zero_memory { - zero(rawptr(next_addr), size) - } - return byte_slice(rawptr(next_addr), size), nil - } - - switch mode { - case .Alloc, .Alloc_Non_Zeroed: - return raw_alloc(s, size, align, mode == .Alloc) - case .Free: - if old_memory == nil { - return nil, nil - } - start := uintptr(raw_data(s.data)) - end := start + uintptr(len(s.data)) - curr_addr := uintptr(old_memory) - - if !(start <= curr_addr && curr_addr < end) { - // panic("Out of bounds memory address passed to stack allocator (free)"); - return nil, .Invalid_Pointer - } - - if curr_addr >= start+uintptr(s.offset) { - // NOTE(bill): Allow double frees - return nil, nil - } - - header := (^Small_Stack_Allocation_Header)(curr_addr - size_of(Small_Stack_Allocation_Header)) - old_offset := int(curr_addr - uintptr(header.padding) - uintptr(raw_data(s.data))) - - s.offset = old_offset - - case .Free_All: - s.offset = 0 - - case .Resize, .Resize_Non_Zeroed: - if old_memory == nil { - return raw_alloc(s, size, align, mode == .Resize) - } - if size == 0 { - return nil, nil - } - - start := uintptr(raw_data(s.data)) - end := start + uintptr(len(s.data)) - curr_addr := uintptr(old_memory) - if !(start <= curr_addr && curr_addr < end) { - // panic("Out of bounds memory address passed to stack allocator (resize)"); - return nil, .Invalid_Pointer - } - - if curr_addr >= start+uintptr(s.offset) { - // NOTE(bill): Treat as a double free - return nil, nil - } - - if old_size == size { - return byte_slice(old_memory, size), nil - } - - data, err := raw_alloc(s, size, align, mode == .Resize) - if err == nil { - runtime.copy(data, byte_slice(old_memory, old_size)) - } - return data, err - - case .Query_Features: - set := (^Allocator_Mode_Set)(old_memory) - if set != nil { - set^ = {.Alloc, .Alloc_Non_Zeroed, .Free, .Free_All, .Resize, .Resize_Non_Zeroed, .Query_Features} - } - return nil, nil - - case .Query_Info: - return nil, .Mode_Not_Implemented - } - - return nil, nil -} - - - - - -Dynamic_Pool :: struct { - block_size: int, - out_band_size: int, - alignment: int, - - unused_blocks: [dynamic]rawptr, - used_blocks: [dynamic]rawptr, - out_band_allocations: [dynamic]rawptr, - - current_block: rawptr, - current_pos: rawptr, - bytes_left: int, - - block_allocator: Allocator, -} - - -DYNAMIC_POOL_BLOCK_SIZE_DEFAULT :: 65536 -DYNAMIC_POOL_OUT_OF_BAND_SIZE_DEFAULT :: 6554 - - - -dynamic_pool_allocator_proc :: proc(allocator_data: rawptr, mode: Allocator_Mode, - size, alignment: int, - old_memory: rawptr, old_size: int, loc := #caller_location) -> ([]byte, Allocator_Error) { - pool := (^Dynamic_Pool)(allocator_data) - - switch mode { - case .Alloc, .Alloc_Non_Zeroed: - return dynamic_pool_alloc_bytes(pool, size) - case .Free: - return nil, .Mode_Not_Implemented - case .Free_All: - dynamic_pool_free_all(pool) - return nil, nil - case .Resize, .Resize_Non_Zeroed: - if old_size >= size { - return byte_slice(old_memory, size), nil - } - data, err := dynamic_pool_alloc_bytes(pool, size) - if err == nil { - runtime.copy(data, byte_slice(old_memory, old_size)) - } - return data, err - - case .Query_Features: - set := (^Allocator_Mode_Set)(old_memory) - if set != nil { - set^ = {.Alloc, .Alloc_Non_Zeroed, .Free_All, .Resize, .Resize_Non_Zeroed, .Query_Features, .Query_Info} - } - return nil, nil - - case .Query_Info: - info := (^Allocator_Query_Info)(old_memory) - if info != nil && info.pointer != nil { - info.size = pool.block_size - info.alignment = pool.alignment - return byte_slice(info, size_of(info^)), nil - } - return nil, nil - } - return nil, nil -} - - -@(require_results) -dynamic_pool_allocator :: proc(pool: ^Dynamic_Pool) -> Allocator { - return Allocator{ - procedure = dynamic_pool_allocator_proc, - data = pool, - } -} - -dynamic_pool_init :: proc(pool: ^Dynamic_Pool, - block_allocator := context.allocator, - array_allocator := context.allocator, - block_size := DYNAMIC_POOL_BLOCK_SIZE_DEFAULT, - out_band_size := DYNAMIC_POOL_OUT_OF_BAND_SIZE_DEFAULT, - alignment := 8) { - pool.block_size = block_size - pool.out_band_size = out_band_size - pool.alignment = alignment - pool.block_allocator = block_allocator - pool.out_band_allocations.allocator = array_allocator - pool. unused_blocks.allocator = array_allocator - pool. used_blocks.allocator = array_allocator -} - -dynamic_pool_destroy :: proc(pool: ^Dynamic_Pool) { - dynamic_pool_free_all(pool) - delete(pool.unused_blocks) - delete(pool.used_blocks) - delete(pool.out_band_allocations) - - zero(pool, size_of(pool^)) -} - - -@(require_results) -dynamic_pool_alloc :: proc(pool: ^Dynamic_Pool, bytes: int) -> (rawptr, Allocator_Error) { - data, err := dynamic_pool_alloc_bytes(pool, bytes) - return raw_data(data), err -} - -@(require_results) -dynamic_pool_alloc_bytes :: proc(p: ^Dynamic_Pool, bytes: int) -> ([]byte, Allocator_Error) { - cycle_new_block :: proc(p: ^Dynamic_Pool) -> (err: Allocator_Error) { - if p.block_allocator.procedure == nil { - panic("You must call pool_init on a Pool before using it") - } - - if p.current_block != nil { - append(&p.used_blocks, p.current_block) - } - - new_block: rawptr - if len(p.unused_blocks) > 0 { - new_block = pop(&p.unused_blocks) - } else { - data: []byte - data, err = p.block_allocator.procedure(p.block_allocator.data, Allocator_Mode.Alloc, - p.block_size, p.alignment, - nil, 0) - new_block = raw_data(data) - } - - p.bytes_left = p.block_size - p.current_pos = new_block - p.current_block = new_block - return - } - - n := align_formula(bytes, p.alignment) - if n > p.block_size { - return nil, .Invalid_Argument - } - if n >= p.out_band_size { - assert(p.block_allocator.procedure != nil) - memory, err := p.block_allocator.procedure(p.block_allocator.data, Allocator_Mode.Alloc, - p.block_size, p.alignment, - nil, 0) - if memory != nil { - append(&p.out_band_allocations, raw_data(memory)) - } - return memory, err - } - - if p.bytes_left < n { - err := cycle_new_block(p) - if err != nil { - return nil, err - } - if p.current_block == nil { - return nil, .Out_Of_Memory - } - } - - memory := p.current_pos - p.current_pos = ([^]byte)(p.current_pos)[n:] - p.bytes_left -= n - return ([^]byte)(memory)[:bytes], nil -} - - -dynamic_pool_reset :: proc(p: ^Dynamic_Pool) { - if p.current_block != nil { - append(&p.unused_blocks, p.current_block) - p.current_block = nil - } - - for block in p.used_blocks { - append(&p.unused_blocks, block) - } - clear(&p.used_blocks) - - for a in p.out_band_allocations { - free(a, p.block_allocator) - } - clear(&p.out_band_allocations) - - p.bytes_left = 0 // Make new allocations call `cycle_new_block` again. -} - -dynamic_pool_free_all :: proc(p: ^Dynamic_Pool) { - dynamic_pool_reset(p) - - for block in p.unused_blocks { - free(block, p.block_allocator) - } - clear(&p.unused_blocks) -} - - -panic_allocator_proc :: proc(allocator_data: rawptr, mode: Allocator_Mode, - size, alignment: int, - old_memory: rawptr, old_size: int,loc := #caller_location) -> ([]byte, Allocator_Error) { - +panic_allocator_proc :: proc( + allocator_data: rawptr, + mode: Allocator_Mode, + size, alignment: int, + old_memory: rawptr, + old_size: int, + loc := #caller_location, +) -> ([]byte, Allocator_Error) { switch mode { case .Alloc: if size > 0 { @@ -836,7 +76,6 @@ panic_allocator_proc :: proc(allocator_data: rawptr, mode: Allocator_Mode, } case .Free_All: panic("mem: panic allocator, .Free_All called", loc=loc) - case .Query_Features: set := (^Allocator_Mode_Set)(old_memory) if set != nil { @@ -847,33 +86,1871 @@ panic_allocator_proc :: proc(allocator_data: rawptr, mode: Allocator_Mode, case .Query_Info: panic("mem: panic allocator, .Query_Info called", loc=loc) } - return nil, nil } + +/* +Arena allocator data. +*/ +Arena :: struct { + data: []byte, + offset: int, + peak_used: int, + temp_count: int, +} + +/* +Arena allocator. + +The arena allocator (also known as a linear allocator, bump allocator, +region allocator) is an allocator that uses a single backing buffer for +allocations. + +The buffer is being used contiguously, from start by end. Each subsequent +allocation occupies the next adjacent region of memory in the buffer. Since +arena allocator does not keep track of any metadata associated with the +allocations and their locations, it is impossible to free individual +allocations. + +The arena allocator can be used for temporary allocations in frame-based memory +management. Games are one example of such applications. A global arena can be +used for any temporary memory allocations, and at the end of each frame all +temporary allocations are freed. Since no temporary object is going to live +longer than a frame, no lifetimes are violated. +*/ @(require_results) -panic_allocator :: proc() -> Allocator { +arena_allocator :: proc(arena: ^Arena) -> Allocator { return Allocator{ - procedure = panic_allocator_proc, - data = nil, + procedure = arena_allocator_proc, + data = arena, } } +/* +Initialize an arena. + +This procedure initializes the arena `a` with memory region `data` as it's +backing buffer. +*/ +arena_init :: proc(a: ^Arena, data: []byte) { + a.data = data + a.offset = 0 + a.peak_used = 0 + a.temp_count = 0 +} + +@(deprecated="prefer 'mem.arena_init'") +init_arena :: proc(a: ^Arena, data: []byte) { + a.data = data + a.offset = 0 + a.peak_used = 0 + a.temp_count = 0 +} + +/* +Allocate memory from an arena. + +This procedure allocates `size` bytes of memory aligned on a boundary specified +by `alignment` from an arena `a`. The allocated memory is zero-initialized. +This procedure returns a pointer to the newly allocated memory region. +*/ +@(require_results) +arena_alloc :: proc( + a: ^Arena, + size: int, + alignment := DEFAULT_ALIGNMENT, + loc := #caller_location, +) -> (rawptr, Allocator_Error) { + bytes, err := arena_alloc_bytes(a, size, alignment, loc) + return raw_data(bytes), err +} + +/* +Allocate memory from an arena. + +This procedure allocates `size` bytes of memory aligned on a boundary specified +by `alignment` from an arena `a`. The allocated memory is zero-initialized. +This procedure returns a slice of the newly allocated memory region. +*/ +@(require_results) +arena_alloc_bytes :: proc( + a: ^Arena, + size: int, + alignment := DEFAULT_ALIGNMENT, + loc := #caller_location, +) -> ([]byte, Allocator_Error) { + bytes, err := arena_alloc_bytes_non_zeroed(a, size, alignment, loc) + if bytes != nil { + zero_slice(bytes) + } + return bytes, err +} + +/* +Allocate non-initialized memory from an arena. + +This procedure allocates `size` bytes of memory aligned on a boundary specified +by `alignment` from an arena `a`. The allocated memory is not explicitly +zero-initialized. This procedure returns a pointer to the newly allocated +memory region. +*/ +@(require_results) +arena_alloc_non_zeroed :: proc( + a: ^Arena, + size: int, + alignment := DEFAULT_ALIGNMENT, + loc := #caller_location, +) -> (rawptr, Allocator_Error) { + bytes, err := arena_alloc_bytes_non_zeroed(a, size, alignment, loc) + return raw_data(bytes), err +} + +/* +Allocate non-initialized memory from an arena. + +This procedure allocates `size` bytes of memory aligned on a boundary specified +by `alignment` from an arena `a`. The allocated memory is not explicitly +zero-initialized. This procedure returns a slice of the newly allocated +memory region. +*/ +@(require_results) +arena_alloc_bytes_non_zeroed :: proc( + a: ^Arena, + size: int, + alignment := DEFAULT_ALIGNMENT, + loc := #caller_location +) -> ([]byte, Allocator_Error) { + if a.data == nil { + panic("Arena is not initialized", loc) + } + #no_bounds_check end := &a.data[a.offset] + ptr := align_forward(end, uintptr(alignment)) + total_size := size + ptr_sub((^byte)(ptr), (^byte)(end)) + if a.offset + total_size > len(a.data) { + return nil, .Out_Of_Memory + } + a.offset += total_size + a.peak_used = max(a.peak_used, a.offset) + return byte_slice(ptr, size), nil +} + +/* +Free all memory to an arena. +*/ +arena_free_all :: proc(a: ^Arena) { + a.offset = 0 +} + +arena_allocator_proc :: proc( + allocator_data: rawptr, + mode: Allocator_Mode, + size: int, + alignment: int, + old_memory: rawptr, + old_size: int, + loc := #caller_location, +) -> ([]byte, Allocator_Error) { + arena := cast(^Arena)allocator_data + switch mode { + case .Alloc: + return arena_alloc_bytes(arena, size, alignment, loc) + case .Alloc_Non_Zeroed: + return arena_alloc_bytes_non_zeroed(arena, size, alignment, loc) + case .Free: + return nil, .Mode_Not_Implemented + case .Free_All: + arena_free_all(arena) + case .Resize: + return default_resize_bytes_align(byte_slice(old_memory, old_size), size, alignment, arena_allocator(arena), loc) + case .Resize_Non_Zeroed: + return default_resize_bytes_align_non_zeroed(byte_slice(old_memory, old_size), size, alignment, arena_allocator(arena), loc) + case .Query_Features: + set := (^Allocator_Mode_Set)(old_memory) + if set != nil { + set^ = {.Alloc, .Alloc_Non_Zeroed, .Free_All, .Resize, .Resize_Non_Zeroed, .Query_Features} + } + return nil, nil + case .Query_Info: + return nil, .Mode_Not_Implemented + } + return nil, nil +} + +/* +Temporary memory region of arena. + +Temporary memory regions of arena act as "savepoints" for arena. When one is +created, the subsequent allocations are done inside the temporary memory +region. When `end_arena_temp_memory` is called, the arena is rolled back, and +all of the memory that was allocated from the arena will be freed. + +Multiple temporary memory regions can exist at the same time for an arena. +*/ +Arena_Temp_Memory :: struct { + arena: ^Arena, + prev_offset: int, +} + +/* +Start a temporary memory region. + +This procedure creates a temporary memory region. After a temporary memory +region is created, all allocations are said to be *inside* the temporary memory +region, until `end_arena_temp_memory` is called. +*/ +@(require_results) +begin_arena_temp_memory :: proc(a: ^Arena) -> Arena_Temp_Memory { + tmp: Arena_Temp_Memory + tmp.arena = a + tmp.prev_offset = a.offset + a.temp_count += 1 + return tmp +} + +/* +End a temporary memory region. + +This procedure ends the temporary memory region for an arena. All of the +allocations *inside* the temporary memory region will be freed to the arena. +*/ +end_arena_temp_memory :: proc(tmp: Arena_Temp_Memory) { + assert(tmp.arena.offset >= tmp.prev_offset) + assert(tmp.arena.temp_count > 0) + tmp.arena.offset = tmp.prev_offset + tmp.arena.temp_count -= 1 +} + +/* Preserved for compatibility */ +Scratch_Allocator :: Scratch +scratch_allocator_init :: scratch_init +scratch_allocator_destroy :: scratch_destroy + +/* +Scratch allocator data. +*/ +Scratch :: struct { + data: []byte, + curr_offset: int, + prev_allocation: rawptr, + backup_allocator: Allocator, + leaked_allocations: [dynamic][]byte, +} + +/* +Scratch allocator. + +The scratch allocator works in a similar way to the `Arena` allocator. The +scratch allocator has a backing buffer, that is being allocated in +contiguous regions, from start to end. + +Each subsequent allocation will be the next adjacent region of memory in the +backing buffer. If the allocation doesn't fit into the remaining space of the +backing buffer, this allocation is put at the start of the buffer, and all +previous allocations will become invalidated. If the allocation doesn't fit +into the backing buffer as a whole, it will be allocated using a backing +allocator, and pointer to the allocated memory region will be put into the +`leaked_allocations` array. + +The `leaked_allocations` array is managed by the `context` allocator. +*/ +@(require_results) +scratch_allocator :: proc(allocator: ^Scratch) -> Allocator { + return Allocator{ + procedure = scratch_allocator_proc, + data = allocator, + } +} + +/* +Initialize scratch allocator. +*/ +scratch_init :: proc(s: ^Scratch, size: int, backup_allocator := context.allocator) -> Allocator_Error { + s.data = make_aligned([]byte, size, 2*align_of(rawptr), backup_allocator) or_return + s.curr_offset = 0 + s.prev_allocation = nil + s.backup_allocator = backup_allocator + s.leaked_allocations.allocator = backup_allocator + return nil +} + +/* +Free all data associated with a scratch allocator. +*/ +scratch_destroy :: proc(s: ^Scratch) { + if s == nil { + return + } + for ptr in s.leaked_allocations { + free_bytes(ptr, s.backup_allocator) + } + delete(s.leaked_allocations) + delete(s.data, s.backup_allocator) + s^ = {} +} + +/* +Allocate memory from scratch allocator. + +This procedure allocates `size` bytes of memory aligned on a boundary specified +by `alignment`. The allocated memory region is zero-initialized. This procedure +returns a pointer to the allocated memory region. +*/ +@(require_results) +scratch_alloc :: proc( + s: ^Scratch, + size: int, + alignment := DEFAULT_ALIGNMENT, + loc := #caller_location, +) -> (rawptr, Allocator_Error) { + bytes, err := scratch_alloc_bytes(s, size, alignment, loc) + return raw_data(bytes), err +} + +/* +Allocate memory from scratch allocator. + +This procedure allocates `size` bytes of memory aligned on a boundary specified +by `alignment`. The allocated memory region is zero-initialized. This procedure +returns a slice of the allocated memory region. +*/ +@(require_results) +scratch_alloc_bytes :: proc( + s: ^Scratch, + size: int, + alignment := DEFAULT_ALIGNMENT, + loc := #caller_location, +) -> ([]byte, Allocator_Error) { + bytes, err := scratch_alloc_bytes_non_zeroed(s, size, alignment, loc) + if bytes != nil { + zero_slice(bytes) + } + return bytes, err +} + +/* +Allocate non-initialized memory from scratch allocator. + +This procedure allocates `size` bytes of memory aligned on a boundary specified +by `alignment`. The allocated memory region is not explicitly zero-initialized. +This procedure returns a pointer to the allocated memory region. +*/ +@(require_results) +scratch_alloc_non_zeroed :: proc( + s: ^Scratch, + size: int, + alignment := DEFAULT_ALIGNMENT, + loc := #caller_location, +) -> (rawptr, Allocator_Error) { + bytes, err := scratch_alloc_bytes_non_zeroed(s, size, alignment, loc) + return raw_data(bytes), err +} + +/* +Allocate non-initialized memory from scratch allocator. + +This procedure allocates `size` bytes of memory aligned on a boundary specified +by `alignment`. The allocated memory region is not explicitly zero-initialized. +This procedure returns a slice of the allocated memory region. +*/ +@(require_results) +scratch_alloc_bytes_non_zeroed :: proc( + s: ^Scratch, + size: int, + alignment := DEFAULT_ALIGNMENT, + loc := #caller_location, +) -> ([]byte, Allocator_Error) { + if s.data == nil { + DEFAULT_BACKING_SIZE :: 4 * Megabyte + if !(context.allocator.procedure != scratch_allocator_proc && context.allocator.data != s) { + panic("cyclic initialization of the scratch allocator with itself", loc) + } + scratch_init(s, DEFAULT_BACKING_SIZE) + } + size := size + size = align_forward_int(size, alignment) + if size <= len(s.data) { + offset := uintptr(0) + if s.curr_offset+size <= len(s.data) { + offset = uintptr(s.curr_offset) + } else { + offset = 0 + } + start := uintptr(raw_data(s.data)) + ptr := align_forward_uintptr(offset+start, uintptr(alignment)) + s.prev_allocation = rawptr(ptr) + s.curr_offset = int(offset) + size + return byte_slice(rawptr(ptr), size), nil + } else { + a := s.backup_allocator + if a.procedure == nil { + a = context.allocator + s.backup_allocator = a + } + ptr, err := alloc_bytes_non_zeroed(size, alignment, a, loc) + if err != nil { + return ptr, err + } + if s.leaked_allocations == nil { + s.leaked_allocations, err = make([dynamic][]byte, a) + } + append(&s.leaked_allocations, ptr) + if logger := context.logger; logger.lowest_level <= .Warning { + if logger.procedure != nil { + logger.procedure(logger.data, .Warning, "mem.Scratch resorted to backup_allocator" , logger.options, loc) + } + } + return ptr, err + } +} + +/* +Free memory to the scratch allocator. + +This procedure frees the memory region allocated at pointer `ptr`. + +If `ptr` is not the latest allocation and is not a leaked allocation, this +operation is a no-op. +*/ +scratch_free :: proc(s: ^Scratch, ptr: rawptr, loc := #caller_location) -> Allocator_Error { + if s.data == nil { + panic("Free on an uninitialized scratch allocator", loc) + } + if ptr == nil { + return nil + } + start := uintptr(raw_data(s.data)) + end := start + uintptr(len(s.data)) + old_ptr := uintptr(ptr) + if s.prev_allocation == ptr { + s.curr_offset = int(uintptr(s.prev_allocation) - start) + s.prev_allocation = nil + return nil + } + if start <= old_ptr && old_ptr < end { + // NOTE(bill): Cannot free this pointer but it is valid + return nil + } + if len(s.leaked_allocations) != 0 { + for data, i in s.leaked_allocations { + ptr := raw_data(data) + if ptr == ptr { + free_bytes(data, s.backup_allocator, loc) + ordered_remove(&s.leaked_allocations, i, loc) + return nil + } + } + } + return .Invalid_Pointer +} + +/* +Free all memory to the scratch allocator. +*/ +scratch_free_all :: proc(s: ^Scratch, loc := #caller_location) { + s.curr_offset = 0 + s.prev_allocation = nil + for ptr in s.leaked_allocations { + free_bytes(ptr, s.backup_allocator, loc) + } + clear(&s.leaked_allocations) +} + +/* +Resize an allocation. + +This procedure resizes a memory region, defined by its location, `old_memory`, +and its size, `old_size` to have a size `size` and alignment `alignment`. The +newly allocated memory, if any is zero-initialized. + +If `old_memory` is `nil`, this procedure acts just like `scratch_alloc()`, +allocating a memory region `size` bytes in size, aligned on a boundary specified +by `alignment`. + +If `size` is 0, this procedure acts just like `scratch_free()`, freeing the +memory region located at an address specified by `old_memory`. + +This procedure returns the pointer to the resized memory region. +*/ +@(require_results) +scratch_resize :: proc( + s: ^Scratch, + old_memory: rawptr, + old_size: int, + size: int, + alignment := DEFAULT_ALIGNMENT, + loc := #caller_location +) -> (rawptr, Allocator_Error) { + bytes, err := scratch_resize_bytes(s, byte_slice(old_memory, old_size), size, alignment, loc) + return raw_data(bytes), err +} + +/* +Resize an allocation. + +This procedure resizes a memory region, specified by `old_data`, to have a size +`size` and alignment `alignment`. The newly allocated memory, if any is +zero-initialized. + +If `old_memory` is `nil`, this procedure acts just like `scratch_alloc()`, +allocating a memory region `size` bytes in size, aligned on a boundary specified +by `alignment`. + +If `size` is 0, this procedure acts just like `scratch_free()`, freeing the +memory region located at an address specified by `old_memory`. + +This procedure returns the slice of the resized memory region. +*/ +@(require_results) +scratch_resize_bytes :: proc( + s: ^Scratch, + old_data: []byte, + size: int, + alignment := DEFAULT_ALIGNMENT, + loc := #caller_location +) -> ([]byte, Allocator_Error) { + bytes, err := scratch_resize_bytes_non_zeroed(s, old_data, size, alignment, loc) + if bytes != nil && size > len(old_data) { + zero_slice(bytes[size:]) + } + return bytes, err +} + +/* +Resize an allocation without zero-initialization. + +This procedure resizes a memory region, defined by its location, `old_memory`, +and its size, `old_size` to have a size `size` and alignment `alignment`. The +newly allocated memory, if any is not explicitly zero-initialized. + +If `old_memory` is `nil`, this procedure acts just like `scratch_alloc()`, +allocating a memory region `size` bytes in size, aligned on a boundary specified +by `alignment`. + +If `size` is 0, this procedure acts just like `scratch_free()`, freeing the +memory region located at an address specified by `old_memory`. + +This procedure returns the pointer to the resized memory region. +*/ +@(require_results) +scratch_resize_non_zeroed :: proc( + s: ^Scratch, + old_memory: rawptr, + old_size: int, + size: int, + alignment := DEFAULT_ALIGNMENT, + loc := #caller_location +) -> (rawptr, Allocator_Error) { + bytes, err := scratch_resize_bytes_non_zeroed(s, byte_slice(old_memory, old_size), size, alignment, loc) + return raw_data(bytes), err +} + +/* +Resize an allocation. + +This procedure resizes a memory region, specified by `old_data`, to have a size +`size` and alignment `alignment`. The newly allocated memory, if any is not +explicitly zero-initialized. + +If `old_memory` is `nil`, this procedure acts just like `scratch_alloc()`, +allocating a memory region `size` bytes in size, aligned on a boundary specified +by `alignment`. + +If `size` is 0, this procedure acts just like `scratch_free()`, freeing the +memory region located at an address specified by `old_memory`. + +This procedure returns the slice of the resized memory region. +*/ +@(require_results) +scratch_resize_bytes_non_zeroed :: proc( + s: ^Scratch, + old_data: []byte, + size: int, + alignment := DEFAULT_ALIGNMENT, + loc := #caller_location +) -> ([]byte, Allocator_Error) { + old_memory := raw_data(old_data) + old_size := len(old_data) + if s.data == nil { + DEFAULT_BACKING_SIZE :: 4 * Megabyte + if !(context.allocator.procedure != scratch_allocator_proc && context.allocator.data != s) { + panic("cyclic initialization of the scratch allocator with itself", loc) + } + scratch_init(s, DEFAULT_BACKING_SIZE) + } + begin := uintptr(raw_data(s.data)) + end := begin + uintptr(len(s.data)) + old_ptr := uintptr(old_memory) + if begin <= old_ptr && old_ptr < end && old_ptr+uintptr(size) < end { + s.curr_offset = int(old_ptr-begin)+size + return byte_slice(old_memory, size), nil + } + data, err := scratch_alloc_bytes_non_zeroed(s, size, alignment, loc) + if err != nil { + return data, err + } + runtime.copy(data, byte_slice(old_memory, old_size)) + err = scratch_free(s, old_memory, loc) + return data, err +} + +scratch_allocator_proc :: proc( + allocator_data: rawptr, + mode: Allocator_Mode, + size, alignment: int, + old_memory: rawptr, + old_size: int, + loc := #caller_location, +) -> ([]byte, Allocator_Error) { + s := (^Scratch)(allocator_data) + size := size + switch mode { + case .Alloc: + return scratch_alloc_bytes(s, size, alignment, loc) + case .Alloc_Non_Zeroed: + return scratch_alloc_bytes_non_zeroed(s, size, alignment, loc) + case .Free: + return nil, scratch_free(s, old_memory, loc) + case .Free_All: + scratch_free_all(s, loc) + case .Resize: + return scratch_resize_bytes(s, byte_slice(old_memory, old_size), size, alignment, loc) + case .Resize_Non_Zeroed: + return scratch_resize_bytes_non_zeroed(s, byte_slice(old_memory, old_size), size, alignment, loc) + case .Query_Features: + set := (^Allocator_Mode_Set)(old_memory) + if set != nil { + set^ = {.Alloc, .Alloc_Non_Zeroed, .Free, .Free_All, .Resize, .Resize_Non_Zeroed, .Query_Features} + } + return nil, nil + case .Query_Info: + return nil, .Mode_Not_Implemented + } + return nil, nil +} + +/* +Stack allocator data. +*/ +Stack :: struct { + data: []byte, + prev_offset: int, + curr_offset: int, + peak_used: int, +} + +/* +Header of a stack allocation. +*/ +Stack_Allocation_Header :: struct { + prev_offset: int, + padding: int, +} + +/* +Stack allocator. + +The stack allocator is an allocator that allocates data in the backing buffer +linearly, from start to end. Each subsequent allocation will get the next +adjacent memory region. + +Unlike arena allocator, the stack allocator saves allocation metadata and has +a strict freeing order. Only the last allocated element can be freed. After the +last allocated element is freed, the next previous allocated element becomes +available for freeing. + +The metadata is stored in the allocation headers, that are located before the +start of each allocated memory region. Each header points to the start of the +previous allocation header. +*/ +@(require_results) +stack_allocator :: proc(stack: ^Stack) -> Allocator { + return Allocator{ + procedure = stack_allocator_proc, + data = stack, + } +} + +/* +Initialize the stack allocator. + +This procedure initializes the stack allocator with a backing buffer specified +by `data` parameter. +*/ +stack_init :: proc(s: ^Stack, data: []byte) { + s.data = data + s.prev_offset = 0 + s.curr_offset = 0 + s.peak_used = 0 +} + +@(deprecated="prefer 'mem.stack_init'") +init_stack :: proc(s: ^Stack, data: []byte) { + s.data = data + s.prev_offset = 0 + s.curr_offset = 0 + s.peak_used = 0 +} + +/* +Allocate memory from stack. + +This procedure allocates `size` bytes of memory, aligned to the boundary +specified by `alignment`. The allocated memory is zero-initialized. This +procedure returns the pointer to the allocated memory. +*/ +@(require_results) +stack_alloc :: proc( + s: ^Stack, + size: int, + alignment := DEFAULT_ALIGNMENT, + loc := #caller_location +) -> (rawptr, Allocator_Error) { + bytes, err := stack_alloc_bytes(s, size, alignment, loc) + return raw_data(bytes), err +} + +/* +Allocate memory from stack. + +This procedure allocates `size` bytes of memory, aligned to the boundary +specified by `alignment`. The allocated memory is zero-initialized. This +procedure returns the slice of the allocated memory. +*/ +@(require_results) +stack_alloc_bytes :: proc( + s: ^Stack, + size: int, + alignment := DEFAULT_ALIGNMENT, + loc := #caller_location +) -> ([]byte, Allocator_Error) { + bytes, err := stack_alloc_bytes_non_zeroed(s, size, alignment, loc) + if bytes != nil { + zero_slice(bytes) + } + return bytes, err +} + +/* +Allocate memory from stack. + +This procedure allocates `size` bytes of memory, aligned to the boundary +specified by `alignment`. The allocated memory is not explicitly +zero-initialized. This procedure returns the pointer to the allocated memory. +*/ +@(require_results) +stack_alloc_non_zeroed :: proc( + s: ^Stack, + size: int, + alignment := DEFAULT_ALIGNMENT, + loc := #caller_location +) -> (rawptr, Allocator_Error) { + bytes, err := stack_alloc_bytes_non_zeroed(s, size, alignment, loc) + return raw_data(bytes), err +} + +/* +Allocate memory from stack. + +This procedure allocates `size` bytes of memory, aligned to the boundary +specified by `alignment`. The allocated memory is not explicitly +zero-initialized. This procedure returns the slice of the allocated memory. +*/ +@(require_results) +stack_alloc_bytes_non_zeroed :: proc( + s: ^Stack, + size: int, + alignment := DEFAULT_ALIGNMENT, + loc := #caller_location +) -> ([]byte, Allocator_Error) { + if s.data == nil { + panic("Stack allocation on an uninitialized stack allocator", loc) + } + curr_addr := uintptr(raw_data(s.data)) + uintptr(s.curr_offset) + padding := calc_padding_with_header( + curr_addr, + uintptr(alignment), + size_of(Stack_Allocation_Header), + ) + if s.curr_offset + padding + size > len(s.data) { + return nil, .Out_Of_Memory + } + s.prev_offset = s.curr_offset + s.curr_offset += padding + next_addr := curr_addr + uintptr(padding) + header := (^Stack_Allocation_Header)(next_addr - size_of(Stack_Allocation_Header)) + header.padding = padding + header.prev_offset = s.prev_offset + s.curr_offset += size + s.peak_used = max(s.peak_used, s.curr_offset) + return byte_slice(rawptr(next_addr), size), nil +} + +/* +Free memory to the stack. + +This procedure frees the memory region starting at `old_memory` to the stack. +If the freeing does is an out of order freeing, the `.Invalid_Pointer` error +is returned. +*/ +stack_free :: proc( + s: ^Stack, + old_memory: rawptr, + loc := #caller_location, +) -> (Allocator_Error) { + if s.data == nil { + panic("Stack free on an uninitialized stack allocator", loc) + } + if old_memory == nil { + return nil + } + start := uintptr(raw_data(s.data)) + end := start + uintptr(len(s.data)) + curr_addr := uintptr(old_memory) + if !(start <= curr_addr && curr_addr < end) { + panic("Out of bounds memory address passed to stack allocator (free)", loc) + } + if curr_addr >= start+uintptr(s.curr_offset) { + // NOTE(bill): Allow double frees + return nil + } + header := (^Stack_Allocation_Header)(curr_addr - size_of(Stack_Allocation_Header)) + old_offset := int(curr_addr - uintptr(header.padding) - uintptr(raw_data(s.data))) + if old_offset != header.prev_offset { + // panic("Out of order stack allocator free"); + return .Invalid_Pointer + } + s.curr_offset = old_offset + s.prev_offset = header.prev_offset + return nil +} + +/* +Free all allocations to the stack. +*/ +stack_free_all :: proc(s: ^Stack, loc := #caller_location) { + s.prev_offset = 0 + s.curr_offset = 0 +} + +/* +Resize an allocation. + +This procedure resizes a memory region, defined by its location, `old_memory`, +and its size, `old_size` to have a size `size` and alignment `alignment`. The +newly allocated memory, if any is zero-initialized. + +If `old_memory` is `nil`, this procedure acts just like `stack_alloc()`, +allocating a memory region `size` bytes in size, aligned on a boundary specified +by `alignment`. + +If `size` is 0, this procedure acts just like `stack_free()`, freeing the +memory region located at an address specified by `old_memory`. + +This procedure returns the pointer to the resized memory region. +*/ +@(require_results) +stack_resize :: proc( + s: ^Stack, + old_memory: rawptr, + old_size: int, + size: int, + alignment := DEFAULT_ALIGNMENT, + loc := #caller_location, +) -> (rawptr, Allocator_Error) { + bytes, err := stack_resize_bytes(s, byte_slice(old_memory, old_size), size, alignment) + return raw_data(bytes), err +} + +/* +Resize an allocation. + +This procedure resizes a memory region, specified by the `old_data` parameter +to have a size `size` and alignment `alignment`. The newly allocated memory, +if any is zero-initialized. + +If `old_memory` is `nil`, this procedure acts just like `stack_alloc()`, +allocating a memory region `size` bytes in size, aligned on a boundary specified +by `alignment`. + +If `size` is 0, this procedure acts just like `stack_free()`, freeing the +memory region located at an address specified by `old_memory`. + +This procedure returns the slice of the resized memory region. +*/ +@(require_results) +stack_resize_bytes :: proc( + s: ^Stack, + old_data: []byte, + size: int, + alignment := DEFAULT_ALIGNMENT, + loc := #caller_location, +) -> ([]byte, Allocator_Error) { + bytes, err := stack_alloc_bytes_non_zeroed(s, size, alignment, loc) + if bytes != nil { + if old_data == nil { + zero_slice(bytes) + } else if size > len(old_data) { + zero_slice(bytes[len(old_data):]) + } + } + return bytes, err +} + +/* +Resize an allocation without zero-initialization. + +This procedure resizes a memory region, defined by its location, `old_memory`, +and its size, `old_size` to have a size `size` and alignment `alignment`. The +newly allocated memory, if any is not explicitly zero-initialized. + +If `old_memory` is `nil`, this procedure acts just like `stack_alloc()`, +allocating a memory region `size` bytes in size, aligned on a boundary specified +by `alignment`. + +If `size` is 0, this procedure acts just like `stack_free()`, freeing the +memory region located at an address specified by `old_memory`. + +This procedure returns the pointer to the resized memory region. +*/ +@(require_results) +stack_resize_non_zeroed :: proc( + s: ^Stack, + old_memory: rawptr, + old_size: int, + size: int, + alignment := DEFAULT_ALIGNMENT, + loc := #caller_location, +) -> (rawptr, Allocator_Error) { + bytes, err := stack_resize_bytes_non_zeroed(s, byte_slice(old_memory, old_size), size, alignment) + return raw_data(bytes), err +} + +/* +Resize an allocation without zero-initialization. + +This procedure resizes a memory region, specified by the `old_data` parameter +to have a size `size` and alignment `alignment`. The newly allocated memory, +if any is not explicitly zero-initialized. + +If `old_memory` is `nil`, this procedure acts just like `stack_alloc()`, +allocating a memory region `size` bytes in size, aligned on a boundary specified +by `alignment`. + +If `size` is 0, this procedure acts just like `stack_free()`, freeing the +memory region located at an address specified by `old_memory`. + +This procedure returns the slice of the resized memory region. +*/ +@(require_results) +stack_resize_bytes_non_zeroed :: proc( + s: ^Stack, + old_data: []byte, + size: int, + alignment := DEFAULT_ALIGNMENT, + loc := #caller_location, +) -> ([]byte, Allocator_Error) { + old_memory := raw_data(old_data) + old_size := len(old_data) + if s.data == nil { + panic("Stack free all on an uninitialized stack allocator", loc) + } + if old_memory == nil { + return stack_alloc_bytes_non_zeroed(s, size, alignment, loc) + } + if size == 0 { + return nil, nil + } + start := uintptr(raw_data(s.data)) + end := start + uintptr(len(s.data)) + curr_addr := uintptr(old_memory) + if !(start <= curr_addr && curr_addr < end) { + panic("Out of bounds memory address passed to stack allocator (resize)") + } + if curr_addr >= start+uintptr(s.curr_offset) { + // NOTE(bill): Allow double frees + return nil, nil + } + if old_size == size { + return byte_slice(old_memory, size), nil + } + header := (^Stack_Allocation_Header)(curr_addr - size_of(Stack_Allocation_Header)) + old_offset := int(curr_addr - uintptr(header.padding) - uintptr(raw_data(s.data))) + if old_offset != header.prev_offset { + data, err := stack_alloc_bytes_non_zeroed(s, size, alignment, loc) + if err == nil { + runtime.copy(data, byte_slice(old_memory, old_size)) + } + return data, err + } + old_memory_size := uintptr(s.curr_offset) - (curr_addr - start) + assert(old_memory_size == uintptr(old_size)) + diff := size - old_size + s.curr_offset += diff // works for smaller sizes too + if diff > 0 { + zero(rawptr(curr_addr + uintptr(diff)), diff) + } + return byte_slice(old_memory, size), nil +} + +stack_allocator_proc :: proc( + allocator_data: rawptr, + mode: Allocator_Mode, + size: int, + alignment: int, + old_memory: rawptr, + old_size: int, + loc := #caller_location, +) -> ([]byte, Allocator_Error) { + s := cast(^Stack)allocator_data + if s.data == nil { + return nil, .Invalid_Argument + } + switch mode { + case .Alloc: + return stack_alloc_bytes(s, size, alignment, loc) + case .Alloc_Non_Zeroed: + return stack_alloc_bytes_non_zeroed(s, size, alignment, loc) + case .Free: + return nil, stack_free(s, old_memory, loc) + case .Free_All: + stack_free_all(s, loc) + case .Resize: + return stack_resize_bytes(s, byte_slice(old_memory, old_size), size, alignment, loc) + case .Resize_Non_Zeroed: + return stack_resize_bytes_non_zeroed(s, byte_slice(old_memory, old_size), size, alignment, loc) + case .Query_Features: + set := (^Allocator_Mode_Set)(old_memory) + if set != nil { + set^ = {.Alloc, .Alloc_Non_Zeroed, .Free, .Free_All, .Resize, .Resize_Non_Zeroed, .Query_Features} + } + return nil, nil + case .Query_Info: + return nil, .Mode_Not_Implemented + } + return nil, nil +} +/* +Allocation header of the small stack allocator. +*/ +Small_Stack_Allocation_Header :: struct { + padding: u8, +} +/* +Small stack allocator data. +*/ +Small_Stack :: struct { + data: []byte, + offset: int, + peak_used: int, +} + +/* +Initialize small stack. + +This procedure initializes the small stack allocator with `data` as its backing +buffer. +*/ +small_stack_init :: proc(s: ^Small_Stack, data: []byte) { + s.data = data + s.offset = 0 + s.peak_used = 0 +} + +@(deprecated="prefer 'small_stack_init'") +init_small_stack :: proc(s: ^Small_Stack, data: []byte) { + s.data = data + s.offset = 0 + s.peak_used = 0 +} + +/* +Small stack allocator. + +The small stack allocator is just like a stack allocator, with the only +difference being an extremely small header size. Unlike the stack allocator, +small stack allows out-of order freeing of memory. + +The memory is allocated in the backing buffer linearly, from start to end. +Each subsequent allocation will get the next adjacent memory region. + +The metadata is stored in the allocation headers, that are located before the +start of each allocated memory region. Each header contains the amount of +padding bytes between that header and end of the previous allocation. +*/ +@(require_results) +small_stack_allocator :: proc(stack: ^Small_Stack) -> Allocator { + return Allocator{ + procedure = small_stack_allocator_proc, + data = stack, + } +} + +/* +Allocate memory from small stack. + +This procedure allocates `size` bytes of memory aligned to a boundary specified +by `alignment`. The allocated memory is zero-initialized. This procedure +returns a pointer to the allocated memory region. +*/ +@(require_results) +small_stack_alloc :: proc( + s: ^Small_Stack, + size: int, + alignment := DEFAULT_ALIGNMENT, + loc := #caller_location, +) -> (rawptr, Allocator_Error) { + bytes, err := small_stack_alloc_bytes(s, size, alignment, loc) + return raw_data(bytes), err +} + +/* +Allocate memory from small stack. + +This procedure allocates `size` bytes of memory aligned to a boundary specified +by `alignment`. The allocated memory is zero-initialized. This procedure +returns a slice of the allocated memory region. +*/ +@(require_results) +small_stack_alloc_bytes :: proc( + s: ^Small_Stack, + size: int, + alignment := DEFAULT_ALIGNMENT, + loc := #caller_location, +) -> ([]byte, Allocator_Error) { + bytes, err := small_stack_alloc_bytes_non_zeroed(s, size, alignment, loc) + if bytes != nil { + zero_slice(bytes) + } + return bytes, err +} + +/* +Allocate memory from small stack. + +This procedure allocates `size` bytes of memory aligned to a boundary specified +by `alignment`. The allocated memory is not explicitly zero-initialized. This +procedure returns a pointer to the allocated memory region. +*/ +@(require_results) +small_stack_alloc_non_zeroed :: proc( + s: ^Small_Stack, + size: int, + alignment := DEFAULT_ALIGNMENT, + loc := #caller_location, +) -> (rawptr, Allocator_Error) { + bytes, err := small_stack_alloc_bytes_non_zeroed(s, size, alignment, loc) + return raw_data(bytes), err +} + +/* +Allocate memory from small stack. + +This procedure allocates `size` bytes of memory aligned to a boundary specified +by `alignment`. The allocated memory is not explicitly zero-initialized. This +procedure returns a slice of the allocated memory region. +*/ +@(require_results) +small_stack_alloc_bytes_non_zeroed :: proc( + s: ^Small_Stack, + size: int, + alignment := DEFAULT_ALIGNMENT, + loc := #caller_location, +) -> ([]byte, Allocator_Error) { + if s.data == nil { + panic("Small stack is not initialized", loc) + } + alignment := alignment + alignment = clamp(alignment, 1, 8*size_of(Stack_Allocation_Header{}.padding)/2) + curr_addr := uintptr(raw_data(s.data)) + uintptr(s.offset) + padding := calc_padding_with_header(curr_addr, uintptr(alignment), size_of(Small_Stack_Allocation_Header)) + if s.offset + padding + size > len(s.data) { + return nil, .Out_Of_Memory + } + s.offset += padding + next_addr := curr_addr + uintptr(padding) + header := (^Small_Stack_Allocation_Header)(next_addr - size_of(Small_Stack_Allocation_Header)) + header.padding = auto_cast padding + s.offset += size + s.peak_used = max(s.peak_used, s.offset) + return byte_slice(rawptr(next_addr), size), nil +} + +/* +Allocate memory from small stack. + +This procedure allocates `size` bytes of memory aligned to a boundary specified +by `alignment`. The allocated memory is not explicitly zero-initialized. This +procedure returns a slice of the allocated memory region. +*/ +small_stack_free :: proc( + s: ^Small_Stack, + old_memory: rawptr, + loc := #caller_location, +) -> Allocator_Error { + if s.data == nil { + panic("Small stack is not initialized", loc) + } + if old_memory == nil { + return nil + } + start := uintptr(raw_data(s.data)) + end := start + uintptr(len(s.data)) + curr_addr := uintptr(old_memory) + if !(start <= curr_addr && curr_addr < end) { + // panic("Out of bounds memory address passed to stack allocator (free)"); + return .Invalid_Pointer + } + if curr_addr >= start+uintptr(s.offset) { + // NOTE(bill): Allow double frees + return nil + } + header := (^Small_Stack_Allocation_Header)(curr_addr - size_of(Small_Stack_Allocation_Header)) + old_offset := int(curr_addr - uintptr(header.padding) - uintptr(raw_data(s.data))) + s.offset = old_offset + return nil +} + +/* +Free all memory to small stack. +*/ +small_stack_free_all :: proc(s: ^Small_Stack) { + s.offset = 0 +} + +/* +Resize an allocation. + +This procedure resizes a memory region, defined by its location, `old_memory`, +and its size, `old_size` to have a size `size` and alignment `alignment`. The +newly allocated memory, if any is zero-initialized. + +If `old_memory` is `nil`, this procedure acts just like `small_stack_alloc()`, +allocating a memory region `size` bytes in size, aligned on a boundary specified +by `alignment`. + +If `size` is 0, this procedure acts just like `small_stack_free()`, freeing the +memory region located at an address specified by `old_memory`. + +This procedure returns the pointer to the resized memory region. +*/ +@(require_results) +small_stack_resize :: proc( + s: ^Small_Stack, + old_memory: rawptr, + old_size: int, + size: int, + alignment := DEFAULT_ALIGNMENT, + loc := #caller_location, +) -> (rawptr, Allocator_Error) { + bytes, err := small_stack_resize_bytes(s, byte_slice(old_memory, old_size), size, alignment, loc) + return raw_data(bytes), err +} + +/* +Resize an allocation. + +This procedure resizes a memory region, specified by the `old_data` parameter +to have a size `size` and alignment `alignment`. The newly allocated memory, +if any is zero-initialized. + +If `old_memory` is `nil`, this procedure acts just like `small_stack_alloc()`, +allocating a memory region `size` bytes in size, aligned on a boundary specified +by `alignment`. + +If `size` is 0, this procedure acts just like `small_stack_free()`, freeing the +memory region located at an address specified by `old_memory`. + +This procedure returns the slice of the resized memory region. +*/ +@(require_results) +small_stack_resize_bytes :: proc( + s: ^Small_Stack, + old_data: []byte, + size: int, + alignment := DEFAULT_ALIGNMENT, + loc := #caller_location, +) -> ([]byte, Allocator_Error) { + bytes, err := small_stack_resize_bytes_non_zeroed(s, old_data, size, alignment, loc) + if bytes != nil { + if old_data == nil { + zero_slice(bytes) + } else if size > len(old_data) { + zero_slice(bytes[len(old_data):]) + } + } + return bytes, err +} + +/* +Resize an allocation without zero-initialization. + +This procedure resizes a memory region, defined by its location, `old_memory`, +and its size, `old_size` to have a size `size` and alignment `alignment`. The +newly allocated memory, if any is not explicitly zero-initialized. + +If `old_memory` is `nil`, this procedure acts just like `small_stack_alloc()`, +allocating a memory region `size` bytes in size, aligned on a boundary specified +by `alignment`. + +If `size` is 0, this procedure acts just like `small_stack_free()`, freeing the +memory region located at an address specified by `old_memory`. + +This procedure returns the pointer to the resized memory region. +*/ +@(require_results) +small_stack_resize_non_zeroed :: proc( + s: ^Small_Stack, + old_memory: rawptr, + old_size: int, + size: int, + alignment := DEFAULT_ALIGNMENT, + loc := #caller_location, +) -> (rawptr, Allocator_Error) { + bytes, err := small_stack_resize_bytes_non_zeroed(s, byte_slice(old_memory, old_size), size, alignment, loc) + return raw_data(bytes), err +} + +/* +Resize an allocation without zero-initialization. + +This procedure resizes a memory region, specified by the `old_data` parameter +to have a size `size` and alignment `alignment`. The newly allocated memory, +if any is not explicitly zero-initialized. + +If `old_memory` is `nil`, this procedure acts just like `small_stack_alloc()`, +allocating a memory region `size` bytes in size, aligned on a boundary specified +by `alignment`. + +If `size` is 0, this procedure acts just like `small_stack_free()`, freeing the +memory region located at an address specified by `old_memory`. + +This procedure returns the slice of the resized memory region. +*/ +@(require_results) +small_stack_resize_bytes_non_zeroed :: proc( + s: ^Small_Stack, + old_data: []byte, + size: int, + alignment := DEFAULT_ALIGNMENT, + loc := #caller_location, +) -> ([]byte, Allocator_Error) { + if s.data == nil { + panic("Small stack is not initialized", loc) + } + old_memory := raw_data(old_data) + old_size := len(old_data) + alignment := alignment + alignment = clamp(alignment, 1, 8*size_of(Stack_Allocation_Header{}.padding)/2) + if old_memory == nil { + return small_stack_alloc_bytes_non_zeroed(s, size, alignment, loc) + } + if size == 0 { + return nil, nil + } + start := uintptr(raw_data(s.data)) + end := start + uintptr(len(s.data)) + curr_addr := uintptr(old_memory) + if !(start <= curr_addr && curr_addr < end) { + // panic("Out of bounds memory address passed to stack allocator (resize)"); + return nil, .Invalid_Pointer + } + if curr_addr >= start+uintptr(s.offset) { + // NOTE(bill): Treat as a double free + return nil, nil + } + if old_size == size { + return byte_slice(old_memory, size), nil + } + data, err := small_stack_alloc_bytes_non_zeroed(s, size, alignment, loc) + if err == nil { + runtime.copy(data, byte_slice(old_memory, old_size)) + } + return data, err + +} + +small_stack_allocator_proc :: proc( + allocator_data: rawptr, + mode: Allocator_Mode, + size, alignment: int, + old_memory: rawptr, + old_size: int, + loc := #caller_location, +) -> ([]byte, Allocator_Error) { + s := cast(^Small_Stack)allocator_data + if s.data == nil { + return nil, .Invalid_Argument + } + switch mode { + case .Alloc: + return small_stack_alloc_bytes(s, size, alignment, loc) + case .Alloc_Non_Zeroed: + return small_stack_alloc_bytes_non_zeroed(s, size, alignment, loc) + case .Free: + return nil, small_stack_free(s, old_memory, loc) + case .Free_All: + small_stack_free_all(s) + case .Resize: + return small_stack_resize_bytes(s, byte_slice(old_memory, old_size), size, alignment, loc) + case .Resize_Non_Zeroed: + return small_stack_resize_bytes_non_zeroed(s, byte_slice(old_memory, old_size), size, alignment, loc) + case .Query_Features: + set := (^Allocator_Mode_Set)(old_memory) + if set != nil { + set^ = {.Alloc, .Alloc_Non_Zeroed, .Free, .Free_All, .Resize, .Resize_Non_Zeroed, .Query_Features} + } + return nil, nil + case .Query_Info: + return nil, .Mode_Not_Implemented + } + return nil, nil +} + + +/* Preserved for compatibility */ +Dynamic_Pool :: Dynamic_Arena +DYNAMIC_POOL_BLOCK_SIZE_DEFAULT :: DYNAMIC_ARENA_BLOCK_SIZE_DEFAULT +DYNAMIC_POOL_OUT_OF_BAND_SIZE_DEFAULT :: DYNAMIC_ARENA_OUT_OF_BAND_SIZE_DEFAULT +dynamic_pool_allocator_proc :: dynamic_arena_allocator_proc +dynamic_pool_free_all :: dynamic_arena_free_all +dynamic_pool_reset :: dynamic_arena_reset +dynamic_pool_alloc_bytes :: dynamic_arena_alloc_bytes +dynamic_pool_alloc :: dynamic_arena_alloc +dynamic_pool_init :: dynamic_arena_init +dynamic_pool_allocator :: dynamic_arena_allocator +dynamic_pool_destroy :: dynamic_arena_destroy + +/* +Default block size for dynamic arena. +*/ +DYNAMIC_ARENA_BLOCK_SIZE_DEFAULT :: 65536 + +/* +Default out-band size of the dynamic arena. +*/ +DYNAMIC_ARENA_OUT_OF_BAND_SIZE_DEFAULT :: 6554 + +/* +Dynamic arena allocator data. +*/ +Dynamic_Arena :: struct { + block_size: int, + out_band_size: int, + alignment: int, + unused_blocks: [dynamic]rawptr, + used_blocks: [dynamic]rawptr, + out_band_allocations: [dynamic]rawptr, + current_block: rawptr, + current_pos: rawptr, + bytes_left: int, + block_allocator: Allocator, +} + +/* +Initialize a dynamic arena. + +This procedure initializes a dynamic arena. The specified `block_allocator` +will be used to allocate arena blocks, and `array_allocator` to allocate +arrays of blocks and out-band blocks. The blocks have the default size of +`block_size` and out-band threshold will be `out_band_size`. All allocations +will be aligned to a boundary specified by `alignment`. +*/ +dynamic_arena_init :: proc( + pool: ^Dynamic_Arena, + block_allocator := context.allocator, + array_allocator := context.allocator, + block_size := DYNAMIC_ARENA_BLOCK_SIZE_DEFAULT, + out_band_size := DYNAMIC_ARENA_OUT_OF_BAND_SIZE_DEFAULT, + alignment := DEFAULT_ALIGNMENT, +) { + pool.block_size = block_size + pool.out_band_size = out_band_size + pool.alignment = alignment + pool.block_allocator = block_allocator + pool.out_band_allocations.allocator = array_allocator + pool.unused_blocks.allocator = array_allocator + pool.used_blocks.allocator = array_allocator +} + +/* +Dynamic arena allocator. + +The dynamic arena allocator uses blocks of a specific size, allocated on-demand +using the block allocator. This allocator acts similarly to arena. All +allocations in a block happen contiguously, from start to end. If an allocation +does not fit into the remaining space of the block, and its size is smaller +than the specified out-band size, a new block is allocated using the +`block_allocator` and the allocation is performed from a newly-allocated block. + +If an allocation has bigger size than the specified out-band size, a new block +is allocated such that the allocation fits into this new block. This is referred +to as an *out-band allocation*. The out-band blocks are kept separately from +normal blocks. + +Just like arena, the dynamic arena does not support freeing of individual +objects. +*/ +@(require_results) +dynamic_arena_allocator :: proc(a: ^Dynamic_Arena) -> Allocator { + return Allocator{ + procedure = dynamic_arena_allocator_proc, + data = a, + } +} + +/* +Destroy a dynamic arena. + +This procedure frees all allocations, made on a dynamic arena, including the +unused blocks, as well as the arrays for storing blocks. +*/ +dynamic_arena_destroy :: proc(a: ^Dynamic_Arena) { + dynamic_arena_free_all(a) + delete(a.unused_blocks) + delete(a.used_blocks) + delete(a.out_band_allocations) + zero(a, size_of(a^)) +} + +@(private="file") +_dynamic_arena_cycle_new_block :: proc(a: ^Dynamic_Arena, loc := #caller_location) -> (err: Allocator_Error) { + if a.block_allocator.procedure == nil { + panic("You must call arena_init on a Pool before using it", loc) + } + if a.current_block != nil { + append(&a.used_blocks, a.current_block, loc=loc) + } + new_block: rawptr + if len(a.unused_blocks) > 0 { + new_block = pop(&a.unused_blocks) + } else { + data: []byte + data, err = a.block_allocator.procedure( + a.block_allocator.data, + Allocator_Mode.Alloc, + a.block_size, + a.alignment, + nil, + 0, + ) + new_block = raw_data(data) + } + a.bytes_left = a.block_size + a.current_pos = new_block + a.current_block = new_block + return +} + +/* +Allocate memory from a dynamic arena. + +This procedure allocates `size` bytes of memory aligned on a boundary specified +by `alignment` from a dynamic arena `a`. The allocated memory is +zero-initialized. This procedure returns a pointer to the newly allocated memory +region. +*/ +@(private, require_results) +dynamic_arena_alloc :: proc(a: ^Dynamic_Arena, size: int, loc := #caller_location) -> (rawptr, Allocator_Error) { + data, err := dynamic_arena_alloc_bytes(a, size, loc) + return raw_data(data), err +} + +/* +Allocate memory from a dynamic arena. + +This procedure allocates `size` bytes of memory aligned on a boundary specified +by `alignment` from a dynamic arena `a`. The allocated memory is +zero-initialized. This procedure returns a slice of the newly allocated memory +region. +*/ +@(require_results) +dynamic_arena_alloc_bytes :: proc(a: ^Dynamic_Arena, size: int, loc := #caller_location) -> ([]byte, Allocator_Error) { + bytes, err := dynamic_arena_alloc_bytes_non_zeroed(a, size, loc) + if bytes != nil { + zero_slice(bytes) + } + return bytes, err +} + +/* +Allocate non-initialized memory from a dynamic arena. + +This procedure allocates `size` bytes of memory aligned on a boundary specified +by `alignment` from a dynamic arena `a`. The allocated memory is not explicitly +zero-initialized. This procedure returns a pointer to the newly allocated +memory region. +*/ +@(require_results) +dynamic_arena_alloc_non_zeroed :: proc(a: ^Dynamic_Arena, size: int, loc := #caller_location) -> (rawptr, Allocator_Error) { + data, err := dynamic_arena_alloc_bytes_non_zeroed(a, size, loc) + return raw_data(data), err +} + +/* +Allocate non-initialized memory from a dynamic arena. + +This procedure allocates `size` bytes of memory aligned on a boundary specified +by `alignment` from a dynamic arena `a`. The allocated memory is not explicitly +zero-initialized. This procedure returns a slice of the newly allocated +memory region. +*/ +@(require_results) +dynamic_arena_alloc_bytes_non_zeroed :: proc(a: ^Dynamic_Arena, size: int, loc := #caller_location) -> ([]byte, Allocator_Error) { + n := align_formula(size, a.alignment) + if n > a.block_size { + return nil, .Invalid_Argument + } + if n >= a.out_band_size { + assert(a.block_allocator.procedure != nil, "Backing block allocator must be initialized", loc=loc) + memory, err := alloc_bytes_non_zeroed(a.block_size, a.alignment, a.block_allocator, loc) + if memory != nil { + append(&a.out_band_allocations, raw_data(memory), loc = loc) + } + return memory, err + } + if a.bytes_left < n { + err := _dynamic_arena_cycle_new_block(a, loc) + if err != nil { + return nil, err + } + if a.current_block == nil { + return nil, .Out_Of_Memory + } + } + memory := a.current_pos + a.current_pos = ([^]byte)(a.current_pos)[n:] + a.bytes_left -= n + return ([^]byte)(memory)[:size], nil +} + +/* +Reset the dynamic arena. + +This procedure frees all the allocations, owned by the dynamic arena, excluding +the unused blocks. +*/ +dynamic_arena_reset :: proc(a: ^Dynamic_Arena, loc := #caller_location) { + if a.current_block != nil { + append(&a.unused_blocks, a.current_block, loc=loc) + a.current_block = nil + } + for block in a.used_blocks { + append(&a.unused_blocks, block, loc=loc) + } + clear(&a.used_blocks) + for allocation in a.out_band_allocations { + free(allocation, a.block_allocator, loc=loc) + } + clear(&a.out_band_allocations) + a.bytes_left = 0 // Make new allocations call `_dynamic_arena_cycle_new_block` again. +} + +/* +Free all memory from a dynamic arena. + +This procedure frees all the allocations, owned by the dynamic arena, including +the unused blocks. +*/ +dynamic_arena_free_all :: proc(a: ^Dynamic_Arena, loc := #caller_location) { + dynamic_arena_reset(a) + for block in a.unused_blocks { + free(block, a.block_allocator, loc) + } + clear(&a.unused_blocks) +} + +/* +Resize an allocation. + +This procedure resizes a memory region, defined by its location, `old_memory`, +and its size, `old_size` to have a size `size` and alignment `alignment`. The +newly allocated memory, if any is zero-initialized. + +If `old_memory` is `nil`, this procedure acts just like `dynamic_arena_alloc()`, +allocating a memory region `size` bytes in size, aligned on a boundary specified +by `alignment`. + +If `size` is 0, this procedure acts just like `dynamic_arena_free()`, freeing +the memory region located at an address specified by `old_memory`. + +This procedure returns the pointer to the resized memory region. +*/ +@(require_results) +dynamic_arena_resize :: proc( + a: ^Dynamic_Arena, + old_memory: rawptr, + old_size: int, + size: int, + loc := #caller_location, +) -> (rawptr, Allocator_Error) { + bytes, err := dynamic_arena_resize_bytes(a, byte_slice(old_memory, old_size), size, loc) + return raw_data(bytes), err +} + +/* +Resize an allocation. + +This procedure resizes a memory region, specified by `old_data`, to have a size +`size` and alignment `alignment`. The newly allocated memory, if any is +zero-initialized. + +If `old_memory` is `nil`, this procedure acts just like `dynamic_arena_alloc()`, +allocating a memory region `size` bytes in size, aligned on a boundary specified +by `alignment`. + +If `size` is 0, this procedure acts just like `dynamic_arena_free()`, freeing the +memory region located at an address specified by `old_memory`. + +This procedure returns the slice of the resized memory region. +*/ +@(require_results) +dynamic_arena_resize_bytes :: proc( + a: ^Dynamic_Arena, + old_data: []byte, + size: int, + loc := #caller_location, +) -> ([]byte, Allocator_Error) { + bytes, err := dynamic_arena_resize_bytes_non_zeroed(a, old_data, size, loc) + if bytes != nil { + if old_data == nil { + zero_slice(bytes) + } else if size > len(old_data) { + zero_slice(bytes[len(old_data):]) + } + } + return bytes, err +} + +/* +Resize an allocation without zero-initialization. + +This procedure resizes a memory region, defined by its location, `old_memory`, +and its size, `old_size` to have a size `size` and alignment `alignment`. The +newly allocated memory, if any is not explicitly zero-initialized. + +If `old_memory` is `nil`, this procedure acts just like `dynamic_arena_alloc()`, +allocating a memory region `size` bytes in size, aligned on a boundary specified +by `alignment`. + +If `size` is 0, this procedure acts just like `dynamic_arena_free()`, freeing the +memory region located at an address specified by `old_memory`. + +This procedure returns the pointer to the resized memory region. +*/ +@(require_results) +dynamic_arena_resize_non_zeroed :: proc( + a: ^Dynamic_Arena, + old_memory: rawptr, + old_size: int, + size: int, + loc := #caller_location, +) -> (rawptr, Allocator_Error) { + bytes, err := dynamic_arena_resize_bytes_non_zeroed(a, byte_slice(old_memory, old_size), size, loc) + return raw_data(bytes), err +} + +/* +Resize an allocation. + +This procedure resizes a memory region, specified by `old_data`, to have a size +`size` and alignment `alignment`. The newly allocated memory, if any is not +explicitly zero-initialized. + +If `old_memory` is `nil`, this procedure acts just like `dynamic_arena_alloc()`, +allocating a memory region `size` bytes in size, aligned on a boundary specified +by `alignment`. + +If `size` is 0, this procedure acts just like `dynamic_arena_free()`, freeing +the memory region located at an address specified by `old_memory`. + +This procedure returns the slice of the resized memory region. +*/ +@(require_results) +dynamic_arena_resize_bytes_non_zeroed :: proc( + a: ^Dynamic_Arena, + old_data: []byte, + size: int, + loc := #caller_location, +) -> ([]byte, Allocator_Error) { + old_memory := raw_data(old_data) + old_size := len(old_data) + if old_size >= size { + return byte_slice(old_memory, size), nil + } + data, err := dynamic_arena_alloc_bytes_non_zeroed(a, size, loc) + if err == nil { + runtime.copy(data, byte_slice(old_memory, old_size)) + } + return data, err +} + +dynamic_arena_allocator_proc :: proc( + allocator_data: rawptr, + mode: Allocator_Mode, + size: int, + alignment: int, + old_memory: rawptr, + old_size: int, + loc := #caller_location, +) -> ([]byte, Allocator_Error) { + arena := (^Dynamic_Arena)(allocator_data) + switch mode { + case .Alloc: + return dynamic_arena_alloc_bytes(arena, size, loc) + case .Alloc_Non_Zeroed: + return dynamic_arena_alloc_bytes_non_zeroed(arena, size, loc) + case .Free: + return nil, .Mode_Not_Implemented + case .Free_All: + dynamic_arena_free_all(arena, loc) + case .Resize: + return dynamic_arena_resize_bytes(arena, byte_slice(old_memory, old_size), size, loc) + case .Resize_Non_Zeroed: + return dynamic_arena_resize_bytes_non_zeroed(arena, byte_slice(old_memory, old_size), size, loc) + case .Query_Features: + set := (^Allocator_Mode_Set)(old_memory) + if set != nil { + set^ = {.Alloc, .Alloc_Non_Zeroed, .Free_All, .Resize, .Resize_Non_Zeroed, .Query_Features, .Query_Info} + } + return nil, nil + case .Query_Info: + info := (^Allocator_Query_Info)(old_memory) + if info != nil && info.pointer != nil { + info.size = arena.block_size + info.alignment = arena.alignment + return byte_slice(info, size_of(info^)), nil + } + return nil, nil + } + return nil, nil +} + + +/* +Header of the buddy block. +*/ Buddy_Block :: struct #align(align_of(uint)) { size: uint, is_free: bool, } +/* +Obtain the next buddy block. +*/ @(require_results) buddy_block_next :: proc(block: ^Buddy_Block) -> ^Buddy_Block { return (^Buddy_Block)(([^]byte)(block)[block.size:]) } +/* +Split the block into two, by truncating the given block to a given size. +*/ @(require_results) buddy_block_split :: proc(block: ^Buddy_Block, size: uint) -> ^Buddy_Block { block := block @@ -894,12 +1971,14 @@ buddy_block_split :: proc(block: ^Buddy_Block, size: uint) -> ^Buddy_Block { return nil } +/* +Coalesce contiguous blocks in a range of blocks into one. +*/ buddy_block_coalescence :: proc(head, tail: ^Buddy_Block) { for { // Keep looping until there are no more buddies to coalesce block := head buddy := buddy_block_next(block) - no_coalescence := true for block < tail && buddy < tail { // make sure the buddies are within the range if block.is_free && buddy.is_free && block.size == buddy.size { @@ -922,28 +2001,26 @@ buddy_block_coalescence :: proc(head, tail: ^Buddy_Block) { } } } - if no_coalescence { return } } } - +/* +Find the best block for storing a given size in a range of blocks. +*/ @(require_results) buddy_block_find_best :: proc(head, tail: ^Buddy_Block, size: uint) -> ^Buddy_Block { assert(size != 0) - best_block: ^Buddy_Block block := head // left buddy := buddy_block_next(block) // right - // The entire memory section between head and tail is free, // just call 'buddy_block_split' to get the allocation if buddy == tail && block.is_free { return buddy_block_split(block, size) } - // Find the block which is the 'best_block' to requested allocation sized for block < tail && buddy < tail { // make sure the buddies are within the range // If both buddies are free, coalesce them together @@ -954,7 +2031,6 @@ buddy_block_find_best :: proc(head, tail: ^Buddy_Block, size: uint) -> ^Buddy_Bl if size <= block.size && (best_block == nil || block.size <= best_block.size) { best_block = block } - block = buddy_block_next(buddy) if block < tail { // Delay the buddy block for the next iteration @@ -962,20 +2038,16 @@ buddy_block_find_best :: proc(head, tail: ^Buddy_Block, size: uint) -> ^Buddy_Bl } continue } - - if block.is_free && size <= block.size && (best_block == nil || block.size <= best_block.size) { best_block = block } - if buddy.is_free && size <= buddy.size && (best_block == nil || buddy.size < best_block.size) { // If each buddy are the same size, then it makes more sense // to pick the buddy as it "bounces around" less best_block = buddy } - if (block.size <= buddy.size) { block = buddy_block_next(buddy) if (block < tail) { @@ -988,23 +2060,33 @@ buddy_block_find_best :: proc(head, tail: ^Buddy_Block, size: uint) -> ^Buddy_Bl buddy = buddy_block_next(buddy) } } - if best_block != nil { // This will handle the case if the 'best_block' is also the perfect fit return buddy_block_split(best_block, size) } - // Maybe out of memory return nil } - +/* +The buddy allocator data. +*/ Buddy_Allocator :: struct { head: ^Buddy_Block, tail: ^Buddy_Block, alignment: uint, } +/* +Buddy allocator. + +The buddy allocator is a type of allocator that splits the backing buffer into +multiple regions called buddy blocks. Initially, the allocator only has one +block with the size of the backing buffer. Upon each allocation, the allocator +finds the smallest block that can fit the size of requested memory region, and +splits the block according to the allocation size. If no block can be found, +the contiguous free blocks are coalesced and the search is performed again. +*/ @(require_results) buddy_allocator :: proc(b: ^Buddy_Allocator) -> Allocator { return Allocator{ @@ -1013,48 +2095,97 @@ buddy_allocator :: proc(b: ^Buddy_Allocator) -> Allocator { } } -buddy_allocator_init :: proc(b: ^Buddy_Allocator, data: []byte, alignment: uint) { - assert(data != nil) - assert(is_power_of_two(uintptr(len(data)))) - assert(is_power_of_two(uintptr(alignment))) +/* +Initialize the buddy allocator. +This procedure initializes the buddy allocator `b` with a backing buffer `data` +and block alignment specified by `alignment`. +*/ +buddy_allocator_init :: proc(b: ^Buddy_Allocator, data: []byte, alignment: uint, loc := #caller_location) { + assert(data != nil) + assert(is_power_of_two(uintptr(len(data))), "Size of the backing buffer must be power of two", loc) + assert(is_power_of_two(uintptr(alignment)), "Alignment must be a power of two", loc) alignment := alignment if alignment < size_of(Buddy_Block) { alignment = size_of(Buddy_Block) } - ptr := raw_data(data) - assert(uintptr(ptr) % uintptr(alignment) == 0, "data is not aligned to minimum alignment") - + assert(uintptr(ptr) % uintptr(alignment) == 0, "data is not aligned to minimum alignment", loc) b.head = (^Buddy_Block)(ptr) - b.head.size = len(data) b.head.is_free = true - b.tail = buddy_block_next(b.head) - b.alignment = alignment } +/* +Get required block size to fit in the allocation as well as the alignment padding. +*/ @(require_results) buddy_block_size_required :: proc(b: ^Buddy_Allocator, size: uint) -> uint { size := size actual_size := b.alignment size += size_of(Buddy_Block) size = align_forward_uint(size, b.alignment) - for size > actual_size { actual_size <<= 1 } - return actual_size } +/* +Allocate memory from a buddy allocator. + +This procedure allocates `size` bytes of memory aligned on a boundary specified +by `alignment`. The allocated memory region is zero-initialized. This procedure +returns a pointer to the allocated memory region. +*/ @(require_results) -buddy_allocator_alloc :: proc(b: ^Buddy_Allocator, size: uint, zeroed: bool) -> ([]byte, Allocator_Error) { +buddy_allocator_alloc :: proc(b: ^Buddy_Allocator, size: uint) -> (rawptr, Allocator_Error) { + bytes, err := buddy_allocator_alloc_bytes(b, size) + return raw_data(bytes), err +} + +/* +Allocate memory from a buddy allocator. + +This procedure allocates `size` bytes of memory aligned on a boundary specified +by `alignment`. The allocated memory region is zero-initialized. This procedure +returns a slice of the allocated memory region. +*/ +@(require_results) +buddy_allocator_alloc_bytes :: proc(b: ^Buddy_Allocator, size: uint) -> ([]byte, Allocator_Error) { + bytes, err := buddy_allocator_alloc_bytes_non_zeroed(b, size) + if bytes != nil { + zero_slice(bytes) + } + return bytes, err +} + +/* +Allocate non-initialized memory from a buddy allocator. + +This procedure allocates `size` bytes of memory aligned on a boundary specified +by `alignment`. The allocated memory region is not explicitly zero-initialized. +This procedure returns a pointer to the allocated memory region. +*/ +@(require_results) +buddy_allocator_alloc_non_zeroed :: proc(b: ^Buddy_Allocator, size: uint) -> (rawptr, Allocator_Error) { + bytes, err := buddy_allocator_alloc_bytes_non_zeroed(b, size) + return raw_data(bytes), err +} + +/* +Allocate non-initialized memory from a buddy allocator. + +This procedure allocates `size` bytes of memory aligned on a boundary specified +by `alignment`. The allocated memory region is not explicitly zero-initialized. +This procedure returns a slice of the allocated memory region. +*/ +@(require_results) +buddy_allocator_alloc_bytes_non_zeroed :: proc(b: ^Buddy_Allocator, size: uint) -> ([]byte, Allocator_Error) { if size != 0 { actual_size := buddy_block_size_required(b, size) - found := buddy_block_find_best(b.head, b.tail, actual_size) if found != nil { // Try to coalesce all the free buddy blocks and then search again @@ -1065,60 +2196,71 @@ buddy_allocator_alloc :: proc(b: ^Buddy_Allocator, size: uint, zeroed: bool) -> return nil, .Out_Of_Memory } found.is_free = false - data := ([^]byte)(found)[b.alignment:][:size] - if zeroed { - zero_slice(data) - } return data, nil } return nil, nil } +/* +Free memory to the buddy allocator. + +This procedure frees the memory region allocated at pointer `ptr`. + +If `ptr` is not the latest allocation and is not a leaked allocation, this +operation is a no-op. +*/ buddy_allocator_free :: proc(b: ^Buddy_Allocator, ptr: rawptr) -> Allocator_Error { if ptr != nil { if !(b.head <= ptr && ptr <= b.tail) { return .Invalid_Pointer } - block := (^Buddy_Block)(([^]byte)(ptr)[-b.alignment:]) block.is_free = true - buddy_block_coalescence(b.head, b.tail) } return nil } -buddy_allocator_proc :: proc(allocator_data: rawptr, mode: Allocator_Mode, - size, alignment: int, - old_memory: rawptr, old_size: int,loc := #caller_location) -> ([]byte, Allocator_Error) { +/* +Free all memory to the buddy allocator. +*/ +buddy_allocator_free_all :: proc(b: ^Buddy_Allocator) { + alignment := b.alignment + head := ([^]byte)(b.head) + tail := ([^]byte)(b.tail) + data := head[:ptr_sub(tail, head)] + buddy_allocator_init(b, data, alignment) +} +buddy_allocator_proc :: proc( + allocator_data: rawptr, + mode: Allocator_Mode, + size, alignment: int, + old_memory: rawptr, + old_size: int, + loc := #caller_location, +) -> ([]byte, Allocator_Error) { b := (^Buddy_Allocator)(allocator_data) - switch mode { - case .Alloc, .Alloc_Non_Zeroed: - return buddy_allocator_alloc(b, uint(size), mode == .Alloc) + case .Alloc: + return buddy_allocator_alloc_bytes(b, uint(size)) + case .Alloc_Non_Zeroed: + return buddy_allocator_alloc_bytes_non_zeroed(b, uint(size)) case .Resize: - return default_resize_bytes_align(byte_slice(old_memory, old_size), size, alignment, buddy_allocator(b)) + return default_resize_bytes_align(byte_slice(old_memory, old_size), size, alignment, buddy_allocator(b), loc) case .Resize_Non_Zeroed: - return default_resize_bytes_align_non_zeroed(byte_slice(old_memory, old_size), size, alignment, buddy_allocator(b)) + return default_resize_bytes_align_non_zeroed(byte_slice(old_memory, old_size), size, alignment, buddy_allocator(b), loc) case .Free: return nil, buddy_allocator_free(b, old_memory) case .Free_All: - - alignment := b.alignment - head := ([^]byte)(b.head) - tail := ([^]byte)(b.tail) - data := head[:ptr_sub(tail, head)] - buddy_allocator_init(b, data, alignment) - + buddy_allocator_free_all(b) case .Query_Features: set := (^Allocator_Mode_Set)(old_memory) if set != nil { set^ = {.Query_Features, .Alloc, .Alloc_Non_Zeroed, .Resize, .Resize_Non_Zeroed, .Free, .Free_All, .Query_Info} } return nil, nil - case .Query_Info: info := (^Allocator_Query_Info)(old_memory) if info != nil && info.pointer != nil { @@ -1126,7 +2268,6 @@ buddy_allocator_proc :: proc(allocator_data: rawptr, mode: Allocator_Mode, if !(b.head <= ptr && ptr <= b.tail) { return nil, .Invalid_Pointer } - block := (^Buddy_Block)(([^]byte)(ptr)[-b.alignment:]) info.size = int(block.size) info.alignment = int(b.alignment) @@ -1134,6 +2275,5 @@ buddy_allocator_proc :: proc(allocator_data: rawptr, mode: Allocator_Mode, } return nil, nil } - return nil, nil } diff --git a/core/mem/doc.odin b/core/mem/doc.odin index 44c93f798..98755d797 100644 --- a/core/mem/doc.odin +++ b/core/mem/doc.odin @@ -1,34 +1,114 @@ /* -package mem implements various types of allocators. +The `mem` package implements various allocators and provides utility procedures +for dealing with memory, pointers and slices. +The documentation below describes basic concepts, applicable to the `mem` +package. -An example of how to use the `Tracking_Allocator` to track subsequent allocations -in your program and report leaks and bad frees: +## Pointers, multipointers, and slices -Example: - package foo +A *pointer* is an abstraction of an *address*, a numberic value representing the +location of an object in memory. That object is said to be *pointed to* by the +pointer. To obtain the address of a pointer, cast it to `uintptr`. - import "core:mem" - import "core:fmt" +A multipointer is a pointer that points to multiple objects. Unlike a pointer, +a multipointer can be indexed, but does not have a definite length. A slice is +a pointer that points to multiple objects equipped with the length, specifying +the amount of objects a slice points to. - _main :: proc() { - // do stuff - } +When object's values are read through a pointer, that operation is called a +*load* operation. When memory is read through a pointer, that operation is +called a *store* operation. Both of these operations can be called a *memory +access operation*. - main :: proc() { - track: mem.Tracking_Allocator - mem.tracking_allocator_init(&track, context.allocator) - defer mem.tracking_allocator_destroy(&track) - context.allocator = mem.tracking_allocator(&track) +## Allocators - _main() +In C and C++ memory models, allocations of objects in memory are typically +treated individually with a generic allocator (The `malloc` procedure). Which in +some scenarios can lead to poor cache utilization, slowdowns on individual +objects' memory management and growing complexity of the code needing to keep +track of the pointers and their lifetimes. - for _, leak in track.allocation_map { - fmt.printf("%v leaked %m\n", leak.location, leak.size) - } - for bad_free in track.bad_free_array { - fmt.printf("%v allocation %p was freed badly\n", bad_free.location, bad_free.memory) - } - } +Using different kinds of *allocators* for different purposes can solve these +problems. The allocators are typically optimized for specific use-cases and +can potentially simplify the memory management code. + +For example, in the context of making a game, having an Arena allocator could +simplify allocations of any temporary memory, because the programmer doesn't +have to keep track of which objects need to be freed every time they are +allocated, because at the end of every frame the whole allocator is reset to +its initial state and all objects are freed at once. + +The allocators have different kinds of restrictions on object lifetimes, sizes, +alignment and can be a significant gain, if used properly. Odin supports +allocators on a language level. + +Operations such as `new`, `free` and `delete` by default will use +`context.allocator`, which can be overridden by the user. When an override +happens all called procedures will inherit the new context and use the same +allocator. + +We will define one concept to simplify the description of some allocator-related +procedures, which is ownership. If the memory was allocated via a specific +allocator, that allocator is said to be the *owner* of that memory region. To +note, unlike Rust, in Odin the memory ownership model is not strict. + +## Alignment + +An address is said to be *aligned to `N` bytes*, if the addresses's numeric +value is divisible by `N`. The number `N` in this case can be referred to as +the *alignment boundary*. Typically an alignment is a power of two integer +value. + +A *natural alignment* of an object is typically equal to its size. For example +a 16 bit integer has a natural alignment of 2 bytes. When an object is not +located on its natural alignment boundary, accesses to that object are +considered *unaligned*. + +Some machines issue a hardware **exception**, or experience **slowdowns** when a +memory access operation occurs from an unaligned address. Examples of such +operations are: + +- SIMD instructions on x86. These instructions require all memory accesses to be + on an address that is aligned to 16 bytes. +- On ARM unaligned loads have an extra cycle penalty. + +As such, many operations that allocate memory in this package allow to +explicitly specify the alignment of allocated pointers/slices. The default +alignment for all operations is specified in a constant `mem.DEFAULT_ALIGNMENT`. + +## Zero by default + +Whenever new memory is allocated, via an allocator, or on the stack, by default +Odin will zero-initialize that memory, even if it wasn't explicitly +initialized. This allows for some convenience in certain scenarios and ease of +debugging, which will not be described in detail here. + +However zero-initialization can be a cause of slowdowns, when allocating large +buffers. For this reason, allocators have `*_non_zeroed` modes of allocation +that allow the user to request for uninitialized memory and will avoid a +relatively expensive zero-filling of the buffer. + +## Naming conventions + +The word `size` is used to denote the **size in bytes**. The word `length` is +used to denote the count of objects. + +The allocation procedures use the following conventions: + +- If the name contains `alloc_bytes` or `resize_bytes`, then the procedure takes + in slice parameters and returns slices. +- If the procedure name contains `alloc` or `resize`, then the procedure takes + in a raw pointer and returns raw pointers. +- If the procedure name contains `free_bytes`, then the procedure takes in a + slice. +- If the procedure name contains `free`, then the procedure takes in a pointer. + +Higher-level allocation procedures follow the following naming scheme: + +- `new`: Allocates a single object +- `free`: Free a single object (opposite of `new`) +- `make`: Allocate a group of objects +- `delete`: Free a group of objects (opposite of `make`) */ package mem diff --git a/core/mem/mem.odin b/core/mem/mem.odin index d423cc1eb..67ed56c39 100644 --- a/core/mem/mem.odin +++ b/core/mem/mem.odin @@ -3,49 +3,185 @@ package mem import "base:runtime" import "base:intrinsics" -Byte :: runtime.Byte -Kilobyte :: runtime.Kilobyte -Megabyte :: runtime.Megabyte -Gigabyte :: runtime.Gigabyte -Terabyte :: runtime.Terabyte -Petabyte :: runtime.Petabyte -Exabyte :: runtime.Exabyte +/* +The size, in bytes, of a single byte. +This constant is equal to the value of `1`. +*/ +Byte :: runtime.Byte + +/* +The size, in bytes, of one kilobyte. + +This constant is equal to the amount of bytes in one kilobyte (also known as +kibibyte), which is equal to 1024 bytes. +*/ +Kilobyte :: runtime.Kilobyte + +/* +The size, in bytes, of one megabyte. + +This constant is equal to the amount of bytes in one megabyte (also known as +mebibyte), which is equal to 1024 kilobyte. +*/ +Megabyte :: runtime.Megabyte + +/* +The size, in bytes, of one gigabyte. + +This constant is equal to the amount of bytes in one gigabyte (also known as +gibiibyte), which is equal to 1024 megabytes. +*/ +Gigabyte :: runtime.Gigabyte + +/* +The size, in bytes, of one terabyte. + +This constant is equal to the amount of bytes in one terabyte (also known as +tebiibyte), which is equal to 1024 gigabytes. +*/ +Terabyte :: runtime.Terabyte + +/* +The size, in bytes, of one petabyte. + +This constant is equal to the amount of bytes in one petabyte (also known as +pebiibyte), which is equal to 1024 terabytes. +*/ +Petabyte :: runtime.Petabyte + +/* +The size, in bytes, of one exabyte. + +This constant is equal to the amount of bytes in one exabyte (also known as +exbibyte), which is equal to 1024 petabytes. +*/ +Exabyte :: runtime.Exabyte + +/* +Set each byte of a memory range to a specific value. + +This procedure copies value specified by the `value` parameter into each of the +`len` bytes of a memory range, located at address `data`. + +This procedure returns the pointer to `data`. +*/ set :: proc "contextless" (data: rawptr, value: byte, len: int) -> rawptr { return runtime.memset(data, i32(value), len) } + +/* +Set each byte of a memory range to zero. + +This procedure copies the value `0` into the `len` bytes of a memory range, +starting at address `data`. + +This procedure returns the pointer to `data`. +*/ zero :: proc "contextless" (data: rawptr, len: int) -> rawptr { intrinsics.mem_zero(data, len) return data } + +/* +Set each byte of a memory range to zero. + +This procedure copies the value `0` into the `len` bytes of a memory range, +starting at address `data`. + +This procedure returns the pointer to `data`. + +Unlike the `zero()` procedure, which can be optimized away or reordered by the +compiler under certain circumstances, `zero_explicit()` procedure can not be +optimized away or reordered with other memory access operations, and the +compiler assumes volatile semantics of the memory. +*/ zero_explicit :: proc "contextless" (data: rawptr, len: int) -> rawptr { // This routine tries to avoid the compiler optimizing away the call, - // so that it is always executed. It is intended to provided + // so that it is always executed. It is intended to provide // equivalent semantics to those provided by the C11 Annex K 3.7.4.1 // memset_s call. intrinsics.mem_zero_volatile(data, len) // Use the volatile mem_zero intrinsics.atomic_thread_fence(.Seq_Cst) // Prevent reordering return data } + +/* +Zero-fill the memory of an object. + +This procedure sets each byte of the object pointed to by the pointer `item` +to zero, and returns the pointer to `item`. +*/ zero_item :: proc "contextless" (item: $P/^$T) -> P { intrinsics.mem_zero(item, size_of(T)) return item } + +/* +Zero-fill the memory of the slice. + +This procedure sets each byte of the slice pointed to by the slice `data` +to zero, and returns the slice `data`. +*/ zero_slice :: proc "contextless" (data: $T/[]$E) -> T { zero(raw_data(data), size_of(E)*len(data)) return data } +/* +Copy bytes from one memory range to another. +This procedure copies `len` bytes of data, from the memory range pointed to by +the `src` pointer into the memory range pointed to by the `dst` pointer, and +returns the `dst` pointer. +*/ copy :: proc "contextless" (dst, src: rawptr, len: int) -> rawptr { intrinsics.mem_copy(dst, src, len) return dst } + +/* +Copy bytes between two non-overlapping memory ranges. + +This procedure copies `len` bytes of data, from the memory range pointed to by +the `src` pointer into the memory range pointed to by the `dst` pointer, and +returns the `dst` pointer. + +This is a slightly more optimized version of the `copy` procedure that requires +that memory ranges specified by the parameters to this procedure are not +overlapping. If the memory ranges specified by `dst` and `src` pointers overlap, +the behavior of this function may be unpredictable. +*/ copy_non_overlapping :: proc "contextless" (dst, src: rawptr, len: int) -> rawptr { intrinsics.mem_copy_non_overlapping(dst, src, len) return dst } +/* +Compare two memory ranges defined by slices. + +This procedure performs a byte-by-byte comparison between memory ranges +specified by slices `a` and `b`, and returns a value, specifying their relative +ordering. + +If the return value is: +- Equal to `-1`, then `a` is "smaller" than `b`. +- Equal to `+1`, then `a` is "bigger" than `b`. +- Equal to `0`, then `a` and `b` are equal. + +The comparison is performed as follows: +1. Each byte, upto `min(len(a), len(b))` bytes is compared between `a` and `b`. + - If the byte in slice `a` is smaller than a byte in slice `b`, then comparison + stops and this procedure returns `-1`. + - If the byte in slice `a` is bigger than a byte in slice `b`, then comparison + stops and this procedure returns `+1`. + - Otherwise the comparison continues until `min(len(a), len(b))` are compared. +2. If all the bytes in the range are equal, then the lengths of the slices are + compared. + - If the length of slice `a` is smaller than the length of slice `b`, then `-1` is returned. + - If the length of slice `b` is smaller than the length of slice `b`, then `+1` is returned. + - Otherwise `0` is returned. +*/ @(require_results) compare :: proc "contextless" (a, b: []byte) -> int { res := compare_byte_ptrs(raw_data(a), raw_data(b), min(len(a), len(b))) @@ -57,16 +193,89 @@ compare :: proc "contextless" (a, b: []byte) -> int { return res } +/* +Compare two memory ranges defined by byte pointers. + +This procedure performs a byte-by-byte comparison between memory ranges of size +`n` located at addresses `a` and `b`, and returns a value, specifying their relative +ordering. + +If the return value is: +- Equal to `-1`, then `a` is "smaller" than `b`. +- Equal to `+1`, then `a` is "bigger" than `b`. +- Equal to `0`, then `a` and `b` are equal. + +The comparison is performed as follows: +1. Each byte, upto `n` bytes is compared between `a` and `b`. + - If the byte in `a` is smaller than a byte in `b`, then comparison stops + and this procedure returns `-1`. + - If the byte in `a` is bigger than a byte in `b`, then comparison stops + and this procedure returns `+1`. + - Otherwise the comparison continues until `n` bytes are compared. +2. If all the bytes in the range are equal, this procedure returns `0`. +*/ @(require_results) compare_byte_ptrs :: proc "contextless" (a, b: ^byte, n: int) -> int #no_bounds_check { return runtime.memory_compare(a, b, n) } +/* +Compare two memory ranges defined by pointers. + +This procedure performs a byte-by-byte comparison between memory ranges of size +`n` located at addresses `a` and `b`, and returns a value, specifying their relative +ordering. + +If the return value is: +- Equal to `-1`, then `a` is "smaller" than `b`. +- Equal to `+1`, then `a` is "bigger" than `b`. +- Equal to `0`, then `a` and `b` are equal. + +The comparison is performed as follows: +1. Each byte, upto `n` bytes is compared between `a` and `b`. + - If the byte in `a` is smaller than a byte in `b`, then comparison stops + and this procedure returns `-1`. + - If the byte in `a` is bigger than a byte in `b`, then comparison stops + and this procedure returns `+1`. + - Otherwise the comparison continues until `n` bytes are compared. +2. If all the bytes in the range are equal, this procedure returns `0`. +*/ +@(require_results) +compare_ptrs :: proc "contextless" (a, b: rawptr, n: int) -> int { + return compare_byte_ptrs((^byte)(a), (^byte)(b), n) +} + +/* +Check whether two objects are equal on binary level. + +This procedure checks whether the memory ranges occupied by objects `a` and +`b` are equal. See `compare_byte_ptrs()` for how this comparison is done. +*/ +@(require_results) +simple_equal :: proc "contextless" (a, b: $T) -> bool where intrinsics.type_is_simple_compare(T) { + a, b := a, b + return compare_byte_ptrs((^byte)(&a), (^byte)(&b), size_of(T)) == 0 +} + +/* +Check if the memory range defined by a slice is zero-filled. + +This procedure checks whether every byte, pointed to by the slice, specified +by the parameter `data`, is zero. If all bytes of the slice are zero, this +procedure returns `true`. Otherwise this procedure returns `false`. +*/ @(require_results) check_zero :: proc(data: []byte) -> bool { return check_zero_ptr(raw_data(data), len(data)) } +/* +Check if the memory range defined defined by a pointer is zero-filled. + +This procedure checks whether each of the `len` bytes, starting at address +`ptr` is zero. If all bytes of this range are zero, this procedure returns +`true`. Otherwise this procedure returns `false`. +*/ @(require_results) check_zero_ptr :: proc(ptr: rawptr, len: int) -> bool { switch { @@ -81,57 +290,99 @@ check_zero_ptr :: proc(ptr: rawptr, len: int) -> bool { case 4: return intrinsics.unaligned_load((^u32)(ptr)) == 0 case 8: return intrinsics.unaligned_load((^u64)(ptr)) == 0 } - start := uintptr(ptr) start_aligned := align_forward_uintptr(start, align_of(uintptr)) end := start + uintptr(len) end_aligned := align_backward_uintptr(end, align_of(uintptr)) - for b in start.. bool where intrinsics.type_is_simple_compare(T) { - a, b := a, b - return compare_byte_ptrs((^byte)(&a), (^byte)(&b), size_of(T)) == 0 -} +/* +Offset a given pointer by a given amount. -@(require_results) -compare_ptrs :: proc "contextless" (a, b: rawptr, n: int) -> int { - return compare_byte_ptrs((^byte)(a), (^byte)(b), n) -} +This procedure offsets the pointer `ptr` to an object of type `T`, by the amount +of bytes specified by `offset*size_of(T)`, and returns the pointer `ptr`. +**Note**: Prefer to use multipointer types, if possible. +*/ ptr_offset :: intrinsics.ptr_offset + +/* +Offset a given pointer by a given amount backwards. + +This procedure offsets the pointer `ptr` to an object of type `T`, by the amount +of bytes specified by `offset*size_of(T)` in the negative direction, and +returns the pointer `ptr`. +*/ ptr_sub :: intrinsics.ptr_sub +/* +Construct a slice from pointer and length. + +This procedure creates a slice, that points to `len` amount of objects located +at an address, specified by `ptr`. +*/ @(require_results) slice_ptr :: proc "contextless" (ptr: ^$T, len: int) -> []T { return ([^]T)(ptr)[:len] } +/* +Construct a byte slice from raw pointer and length. + +This procedure creates a byte slice, that points to `len` amount of bytes +located at an address specified by `data`. +*/ @(require_results) byte_slice :: #force_inline proc "contextless" (data: rawptr, #any_int len: int) -> []byte { return ([^]u8)(data)[:max(len, 0)] } +/* +Create a byte slice from pointer and length. + +This procedure creates a byte slice, pointing to `len` objects, starting from +the address specified by `ptr`. +*/ +@(require_results) +ptr_to_bytes :: proc "contextless" (ptr: ^$T, len := 1) -> []byte { + return transmute([]byte)Raw_Slice{ptr, len*size_of(T)} +} + +/* +Obtain the slice, pointing to the contents of `any`. + +This procedure returns the slice, pointing to the contents of the specified +value of the `any` type. +*/ +@(require_results) +any_to_bytes :: proc "contextless" (val: any) -> []byte { + ti := type_info_of(val.id) + size := ti != nil ? ti.size : 0 + return transmute([]byte)Raw_Slice{val.data, size} +} + +/* +Obtain a byte slice from any slice. + +This procedure returns a slice, that points to the same bytes as the slice, +specified by `slice` and returns the resulting byte slice. +*/ @(require_results) slice_to_bytes :: proc "contextless" (slice: $E/[]$T) -> []byte { s := transmute(Raw_Slice)slice @@ -139,6 +390,15 @@ slice_to_bytes :: proc "contextless" (slice: $E/[]$T) -> []byte { return transmute([]byte)s } +/* +Transmute slice to a different type. + +This procedure performs an operation similar to transmute, returning a slice of +type `T` that points to the same bytes as the slice specified by `slice` +parameter. Unlike plain transmute operation, this procedure adjusts the length +of the resulting slice, such that the resulting slice points to the correct +amount of objects to cover the memory region pointed to by `slice`. +*/ @(require_results) slice_data_cast :: proc "contextless" ($T: typeid/[]$A, slice: $S/[]$B) -> T { when size_of(A) == 0 || size_of(B) == 0 { @@ -150,12 +410,25 @@ slice_data_cast :: proc "contextless" ($T: typeid/[]$A, slice: $S/[]$B) -> T { } } +/* +Obtain data and length of a slice. + +This procedure returns the pointer to the start of the memory region pointed to +by slice `slice` and the length of the slice. +*/ @(require_results) slice_to_components :: proc "contextless" (slice: $E/[]$T) -> (data: ^T, len: int) { s := transmute(Raw_Slice)slice return (^T)(s.data), s.len } +/* +Create a dynamic array from slice. + +This procedure creates a dynamic array, using slice `backing` as the backing +buffer for the dynamic array. The resulting dynamic array can not grow beyond +the size of the specified slice. +*/ @(require_results) buffer_from_slice :: proc "contextless" (backing: $T/[]$E) -> [dynamic]E { return transmute([dynamic]E)Raw_Dynamic_Array{ @@ -169,19 +442,12 @@ buffer_from_slice :: proc "contextless" (backing: $T/[]$E) -> [dynamic]E { } } -@(require_results) -ptr_to_bytes :: proc "contextless" (ptr: ^$T, len := 1) -> []byte { - return transmute([]byte)Raw_Slice{ptr, len*size_of(T)} -} - -@(require_results) -any_to_bytes :: proc "contextless" (val: any) -> []byte { - ti := type_info_of(val.id) - size := ti != nil ? ti.size : 0 - return transmute([]byte)Raw_Slice{val.data, size} -} - +/* +Check whether a number is a power of two. +This procedure checks whether a given pointer-sized unsigned integer contains +a power-of-two value. +*/ @(require_results) is_power_of_two :: proc "contextless" (x: uintptr) -> bool { if x <= 0 { @@ -190,66 +456,167 @@ is_power_of_two :: proc "contextless" (x: uintptr) -> bool { return (x & (x-1)) == 0 } +/* +Check if a pointer is aligned. + +This procedure checks whether a pointer `x` is aligned to a boundary specified +by `align`, and returns `true` if the pointer is aligned, and false otherwise. +*/ +is_aligned :: proc "contextless" (x: rawptr, align: int) -> bool { + p := uintptr(x) + return (p & (1< uintptr { + assert(is_power_of_two(align)) + return (ptr + align-1) & ~(align-1) +} + +/* +Align pointer forward. + +This procedure returns the next address after `ptr`, that is located on the +alignment boundary specified by `align`. If `ptr` is already aligned to `align` +bytes, `ptr` is returned. + +The specified alignment must be a power of 2. +*/ @(require_results) align_forward :: proc(ptr: rawptr, align: uintptr) -> rawptr { return rawptr(align_forward_uintptr(uintptr(ptr), align)) } -@(require_results) -align_forward_uintptr :: proc(ptr, align: uintptr) -> uintptr { - assert(is_power_of_two(align)) +/* +Align int forward. - p := ptr - modulo := p & (align-1) - if modulo != 0 { - p += align - modulo - } - return p -} +This procedure returns the next address after `ptr`, that is located on the +alignment boundary specified by `align`. If `ptr` is already aligned to `align` +bytes, `ptr` is returned. +The specified alignment must be a power of 2. +*/ @(require_results) align_forward_int :: proc(ptr, align: int) -> int { return int(align_forward_uintptr(uintptr(ptr), uintptr(align))) } + +/* +Align uint forward. + +This procedure returns the next address after `ptr`, that is located on the +alignment boundary specified by `align`. If `ptr` is already aligned to `align` +bytes, `ptr` is returned. + +The specified alignment must be a power of 2. +*/ @(require_results) align_forward_uint :: proc(ptr, align: uint) -> uint { return uint(align_forward_uintptr(uintptr(ptr), uintptr(align))) } +/* +Align uintptr backwards. + +This procedure returns the previous address before `ptr`, that is located on the +alignment boundary specified by `align`. If `ptr` is already aligned to `align` +bytes, `ptr` is returned. + +The specified alignment must be a power of 2. +*/ +@(require_results) +align_backward_uintptr :: proc(ptr, align: uintptr) -> uintptr { + assert(is_power_of_two(align)) + return ptr & ~(align-1) +} + +/* +Align rawptr backwards. + +This procedure returns the previous address before `ptr`, that is located on the +alignment boundary specified by `align`. If `ptr` is already aligned to `align` +bytes, `ptr` is returned. + +The specified alignment must be a power of 2. +*/ @(require_results) align_backward :: proc(ptr: rawptr, align: uintptr) -> rawptr { return rawptr(align_backward_uintptr(uintptr(ptr), align)) } -@(require_results) -align_backward_uintptr :: proc(ptr, align: uintptr) -> uintptr { - return align_forward_uintptr(ptr - align + 1, align) -} +/* +Align int backwards. +This procedure returns the previous address before `ptr`, that is located on the +alignment boundary specified by `align`. If `ptr` is already aligned to `align` +bytes, `ptr` is returned. + +The specified alignment must be a power of 2. +*/ @(require_results) align_backward_int :: proc(ptr, align: int) -> int { return int(align_backward_uintptr(uintptr(ptr), uintptr(align))) } + +/* +Align uint backwards. + +This procedure returns the previous address before `ptr`, that is located on the +alignment boundary specified by `align`. If `ptr` is already aligned to `align` +bytes, `ptr` is returned. + +The specified alignment must be a power of 2. +*/ @(require_results) align_backward_uint :: proc(ptr, align: uint) -> uint { return uint(align_backward_uintptr(uintptr(ptr), uintptr(align))) } +/* +Create a context with a given allocator. + +This procedure returns a copy of the current context with the allocator replaced +by the allocator `a`. +*/ @(require_results) context_from_allocator :: proc(a: Allocator) -> type_of(context) { context.allocator = a return context } +/* +Copy the value from a pointer into a value. + +This procedure copies the object of type `T` pointed to by the pointer `ptr` +into a new stack-allocated value and returns that value. +*/ @(require_results) reinterpret_copy :: proc "contextless" ($T: typeid, ptr: rawptr) -> (value: T) { copy(&value, ptr, size_of(T)) return } +/* +Dynamic array with a fixed capacity buffer. +This type represents dynamic arrays with a fixed-size backing buffer. Upon +allocating memory beyond reaching the maximum capacity, allocations from fixed +byte buffers return `nil` and no error. +*/ Fixed_Byte_Buffer :: distinct [dynamic]byte +/* +Create a fixed byte buffer from a slice. +*/ @(require_results) make_fixed_byte_buffer :: proc "contextless" (backing: []byte) -> Fixed_Byte_Buffer { s := transmute(Raw_Slice)backing @@ -264,40 +631,60 @@ make_fixed_byte_buffer :: proc "contextless" (backing: []byte) -> Fixed_Byte_Buf return transmute(Fixed_Byte_Buffer)d } +/* +General-purpose align formula. - +This procedure is equivalent to `align_forward`, but it does not require the +alignment to be a power of two. +*/ @(require_results) align_formula :: proc "contextless" (size, align: int) -> int { result := size + align-1 return result - result%align } +/* +Calculate the padding for header preceding aligned data. + +This procedure returns the padding, following the specified pointer `ptr` that +will be able to fit in a header of the size `header_size`, immediately +preceding the memory region, aligned on a boundary specified by `align`. See +the following diagram for a visual representation. + + header size + |<------>| + +---+--------+------------- - - - + | HEADER | DATA... + +---+--------+------------- - - - + ^ ^ + |<---------->| + | padding | + ptr aligned ptr + +The function takes in `ptr` and `header_size`, as well as the required +alignment for `DATA`. The return value of the function is the padding between +`ptr` and `aligned_ptr` that will be able to fit the header. +*/ @(require_results) calc_padding_with_header :: proc "contextless" (ptr: uintptr, align: uintptr, header_size: int) -> int { p, a := ptr, align modulo := p & (a-1) - padding := uintptr(0) if modulo != 0 { padding = a - modulo } - needed_space := uintptr(header_size) if padding < needed_space { needed_space -= padding - if needed_space & (a-1) > 0 { padding += align * (1+(needed_space/align)) } else { padding += align * (needed_space/align) } } - return int(padding) } - - @(require_results, deprecated="prefer 'slice.clone'") clone_slice :: proc(slice: $T/[]$E, allocator := context.allocator, loc := #caller_location) -> (new_slice: T) { new_slice, _ = make(T, len(slice), allocator, loc) diff --git a/core/mem/mutex_allocator.odin b/core/mem/mutex_allocator.odin index 591703eab..d2c527fdb 100644 --- a/core/mem/mutex_allocator.odin +++ b/core/mem/mutex_allocator.odin @@ -3,17 +3,31 @@ package mem import "core:sync" +/* +The data for mutex allocator. +*/ Mutex_Allocator :: struct { backing: Allocator, mutex: sync.Mutex, } +/* +Initialize the mutex allocator. + +This procedure initializes the mutex allocator using `backin_allocator` as the +allocator that will be used to pass all allocation requests through. +*/ mutex_allocator_init :: proc(m: ^Mutex_Allocator, backing_allocator: Allocator) { m.backing = backing_allocator m.mutex = {} } +/* +Mutex allocator. +The mutex allocator is a wrapper for allocators that is used to serialize all +allocator requests across multiple threads. +*/ @(require_results) mutex_allocator :: proc(m: ^Mutex_Allocator) -> Allocator { return Allocator{ @@ -22,11 +36,16 @@ mutex_allocator :: proc(m: ^Mutex_Allocator) -> Allocator { } } -mutex_allocator_proc :: proc(allocator_data: rawptr, mode: Allocator_Mode, - size, alignment: int, - old_memory: rawptr, old_size: int, loc := #caller_location) -> (result: []byte, err: Allocator_Error) { +mutex_allocator_proc :: proc( + allocator_data: rawptr, + mode: Allocator_Mode, + size: int, + alignment: int, + old_memory: rawptr, + old_size: int, + loc := #caller_location, +) -> (result: []byte, err: Allocator_Error) { m := (^Mutex_Allocator)(allocator_data) - sync.mutex_guard(&m.mutex) return m.backing.procedure(m.backing.data, mode, size, alignment, old_memory, old_size, loc) } diff --git a/core/mem/raw.odin b/core/mem/raw.odin index f56206957..41c91555e 100644 --- a/core/mem/raw.odin +++ b/core/mem/raw.odin @@ -3,26 +3,100 @@ package mem import "base:builtin" import "base:runtime" -Raw_Any :: runtime.Raw_Any -Raw_String :: runtime.Raw_String -Raw_Cstring :: runtime.Raw_Cstring -Raw_Slice :: runtime.Raw_Slice -Raw_Dynamic_Array :: runtime.Raw_Dynamic_Array -Raw_Map :: runtime.Raw_Map -Raw_Soa_Pointer :: runtime.Raw_Soa_Pointer +/* +Memory layout of the `any` type. +*/ +Raw_Any :: runtime.Raw_Any -Raw_Complex32 :: runtime.Raw_Complex32 -Raw_Complex64 :: runtime.Raw_Complex64 -Raw_Complex128 :: runtime.Raw_Complex128 -Raw_Quaternion64 :: runtime.Raw_Quaternion64 +/* +Memory layout of the `string` type. +*/ +Raw_String :: runtime.Raw_String + +/* +Memory layout of the `cstring` type. +*/ +Raw_Cstring :: runtime.Raw_Cstring + +/* +Memory layout of `[]T` types. +*/ +Raw_Slice :: runtime.Raw_Slice + +/* +Memory layout of `[dynamic]T` types. +*/ +Raw_Dynamic_Array :: runtime.Raw_Dynamic_Array + +/* +Memory layout of `map[K]V` types. +*/ +Raw_Map :: runtime.Raw_Map + +/* +Memory layout of `#soa []T` types. +*/ +Raw_Soa_Pointer :: runtime.Raw_Soa_Pointer + +/* +Memory layout of the `complex32` type. +*/ +Raw_Complex32 :: runtime.Raw_Complex32 + +/* +Memory layout of the `complex64` type. +*/ +Raw_Complex64 :: runtime.Raw_Complex64 + +/* +Memory layout of the `complex128` type. +*/ +Raw_Complex128 :: runtime.Raw_Complex128 + +/* +Memory layout of the `quaternion64` type. +*/ +Raw_Quaternion64 :: runtime.Raw_Quaternion64 + +/* +Memory layout of the `quaternion128` type. +*/ Raw_Quaternion128 :: runtime.Raw_Quaternion128 + +/* +Memory layout of the `quaternion256` type. +*/ Raw_Quaternion256 :: runtime.Raw_Quaternion256 -Raw_Quaternion64_Vector_Scalar :: runtime.Raw_Quaternion64_Vector_Scalar + +/* +Memory layout of the `quaternion64` type. +*/ +Raw_Quaternion64_Vector_Scalar :: runtime.Raw_Quaternion64_Vector_Scalar + +/* +Memory layout of the `quaternion128` type. +*/ Raw_Quaternion128_Vector_Scalar :: runtime.Raw_Quaternion128_Vector_Scalar + +/* +Memory layout of the `quaternion256` type. +*/ Raw_Quaternion256_Vector_Scalar :: runtime.Raw_Quaternion256_Vector_Scalar +/* +Create a value of the any type. + +This procedure creates a value with type `any` that points to an object with +typeid `id` located at an address specified by `data`. +*/ make_any :: proc "contextless" (data: rawptr, id: typeid) -> any { return transmute(any)Raw_Any{data, id} } +/* +Obtain pointer to the data. + +This procedure returns the pointer to the data of a slice, string, or a dynamic +array. +*/ raw_data :: builtin.raw_data diff --git a/core/mem/rollback_stack_allocator.odin b/core/mem/rollback_stack_allocator.odin index f5e428d87..43ef10fe9 100644 --- a/core/mem/rollback_stack_allocator.odin +++ b/core/mem/rollback_stack_allocator.odin @@ -1,52 +1,36 @@ package mem -// The Rollback Stack Allocator was designed for the test runner to be fast, -// able to grow, and respect the Tracking Allocator's requirement for -// individual frees. It is not overly concerned with fragmentation, however. -// -// It has support for expansion when configured with a block allocator and -// limited support for out-of-order frees. -// -// Allocation has constant-time best and usual case performance. -// At worst, it is linear according to the number of memory blocks. -// -// Allocation follows a first-fit strategy when there are multiple memory -// blocks. -// -// Freeing has constant-time best and usual case performance. -// At worst, it is linear according to the number of memory blocks and number -// of freed items preceding the last item in a block. -// -// Resizing has constant-time performance, if it's the last item in a block, or -// the new size is smaller. Naturally, this becomes linear-time if there are -// multiple blocks to search for the pointer's owning block. Otherwise, the -// allocator defaults to a combined alloc & free operation internally. -// -// Out-of-order freeing is accomplished by collapsing a run of freed items -// from the last allocation backwards. -// -// Each allocation has an overhead of 8 bytes and any extra bytes to satisfy -// the requested alignment. - import "base:runtime" +/* +Rollback stack default block size. +*/ ROLLBACK_STACK_DEFAULT_BLOCK_SIZE :: 4 * Megabyte -// This limitation is due to the size of `prev_ptr`, but it is only for the -// head block; any allocation in excess of the allocator's `block_size` is -// valid, so long as the block allocator can handle it. -// -// This is because allocations over the block size are not split up if the item -// within is freed; they are immediately returned to the block allocator. +/* +Rollback stack max head block size. + +This limitation is due to the size of `prev_ptr`, but it is only for the +head block; any allocation in excess of the allocator's `block_size` is +valid, so long as the block allocator can handle it. + +This is because allocations over the block size are not split up if the item +within is freed; they are immediately returned to the block allocator. +*/ ROLLBACK_STACK_MAX_HEAD_BLOCK_SIZE :: 2 * Gigabyte - +/* +Allocation header of the rollback stack allocator. +*/ Rollback_Stack_Header :: bit_field u64 { prev_offset: uintptr | 32, is_free: bool | 1, prev_ptr: uintptr | 31, } +/* +Block header of the rollback stack allocator. +*/ Rollback_Stack_Block :: struct { next_block: ^Rollback_Stack_Block, last_alloc: rawptr, @@ -54,13 +38,15 @@ Rollback_Stack_Block :: struct { buffer: []byte, } +/* +Rollback stack allocator data. +*/ Rollback_Stack :: struct { head: ^Rollback_Stack_Block, block_size: int, block_allocator: Allocator, } - @(private="file", require_results) rb_ptr_in_bounds :: proc(block: ^Rollback_Stack_Block, ptr: rawptr) -> bool { start := raw_data(block.buffer) @@ -110,6 +96,9 @@ rb_rollback_block :: proc(block: ^Rollback_Stack_Block, header: ^Rollback_Stack_ } } +/* +Free memory to a rollback stack allocator. +*/ @(private="file", require_results) rb_free :: proc(stack: ^Rollback_Stack, ptr: rawptr) -> Allocator_Error { parent, block, header := rb_find_ptr(stack, ptr) or_return @@ -128,6 +117,9 @@ rb_free :: proc(stack: ^Rollback_Stack, ptr: rawptr) -> Allocator_Error { return nil } +/* +Free all memory owned by the rollback stack allocator. +*/ @(private="file") rb_free_all :: proc(stack: ^Rollback_Stack) { for block := stack.head.next_block; block != nil; /**/ { @@ -141,45 +133,75 @@ rb_free_all :: proc(stack: ^Rollback_Stack) { stack.head.offset = 0 } -@(private="file", require_results) -rb_resize :: proc(stack: ^Rollback_Stack, ptr: rawptr, old_size, size, alignment: int) -> (result: []byte, err: Allocator_Error) { - if ptr != nil { - if block, _, ok := rb_find_last_alloc(stack, ptr); ok { - // `block.offset` should never underflow because it is contingent - // on `old_size` in the first place, assuming sane arguments. - assert(block.offset >= cast(uintptr)old_size, "Rollback Stack Allocator received invalid `old_size`.") - - if block.offset + cast(uintptr)size - cast(uintptr)old_size < cast(uintptr)len(block.buffer) { - // Prevent singleton allocations from fragmenting by forbidding - // them to shrink, removing the possibility of overflow bugs. - if len(block.buffer) <= stack.block_size { - block.offset += cast(uintptr)size - cast(uintptr)old_size - } - #no_bounds_check return (cast([^]byte)ptr)[:size], nil - } - } +/* +Allocate memory using the rollback stack allocator. +*/ +@(require_results) +rb_alloc :: proc( + stack: ^Rollback_Stack, + size: int, + alignment := DEFAULT_ALIGNMENT, + loc := #caller_location, +) -> (rawptr, Allocator_Error) { + bytes, err := rb_alloc_bytes_non_zeroed(stack, size, alignment, loc) + if bytes != nil { + zero_slice(bytes) } - - result = rb_alloc(stack, size, alignment) or_return - runtime.mem_copy_non_overlapping(raw_data(result), ptr, old_size) - err = rb_free(stack, ptr) - - return + return raw_data(bytes), err } -@(private="file", require_results) -rb_alloc :: proc(stack: ^Rollback_Stack, size, alignment: int) -> (result: []byte, err: Allocator_Error) { +/* +Allocate memory using the rollback stack allocator. +*/ +@(require_results) +rb_alloc_bytes :: proc( + stack: ^Rollback_Stack, + size: int, + alignment := DEFAULT_ALIGNMENT, + loc := #caller_location, +) -> ([]byte, Allocator_Error) { + bytes, err := rb_alloc_bytes_non_zeroed(stack, size, alignment, loc) + if bytes != nil { + zero_slice(bytes) + } + return bytes, err +} + +/* +Allocate non-initialized memory using the rollback stack allocator. +*/ +@(require_results) +rb_alloc_non_zeroed :: proc( + stack: ^Rollback_Stack, + size: int, + alignment := DEFAULT_ALIGNMENT, + loc := #caller_location, +) -> (rawptr, Allocator_Error) { + bytes, err := rb_alloc_bytes_non_zeroed(stack, size, alignment, loc) + return raw_data(bytes), err +} + +/* +Allocate non-initialized memory using the rollback stack allocator. +*/ +@(require_results) +rb_alloc_bytes_non_zeroed :: proc( + stack: ^Rollback_Stack, + size: int, + alignment := DEFAULT_ALIGNMENT, + loc := #caller_location, +) -> (result: []byte, err: Allocator_Error) { + assert(size >= 0, "Size must be positive or zero.", loc) + assert(is_power_of_two(cast(uintptr)alignment), "Alignment must be a power of two.", loc) parent: ^Rollback_Stack_Block for block := stack.head; /**/; block = block.next_block { when !ODIN_DISABLE_ASSERT { allocated_new_block: bool } - if block == nil { if stack.block_allocator.procedure == nil { return nil, .Out_Of_Memory } - minimum_size_required := size_of(Rollback_Stack_Header) + size + alignment - 1 new_block_size := max(minimum_size_required, stack.block_size) block = rb_make_block(new_block_size, stack.block_allocator) or_return @@ -188,10 +210,8 @@ rb_alloc :: proc(stack: ^Rollback_Stack, size, alignment: int) -> (result: []byt allocated_new_block = true } } - start := raw_data(block.buffer)[block.offset:] padding := cast(uintptr)calc_padding_with_header(cast(uintptr)start, cast(uintptr)alignment, size_of(Rollback_Stack_Header)) - if block.offset + padding + cast(uintptr)size > cast(uintptr)len(block.buffer) { when !ODIN_DISABLE_ASSERT { if allocated_new_block { @@ -201,54 +221,150 @@ rb_alloc :: proc(stack: ^Rollback_Stack, size, alignment: int) -> (result: []byt parent = block continue } - header := cast(^Rollback_Stack_Header)(start[padding - size_of(Rollback_Stack_Header):]) ptr := start[padding:] - header^ = { prev_offset = block.offset, prev_ptr = uintptr(0) if block.last_alloc == nil else cast(uintptr)block.last_alloc - cast(uintptr)raw_data(block.buffer), is_free = false, } - block.last_alloc = ptr block.offset += padding + cast(uintptr)size - if len(block.buffer) > stack.block_size { // This block exceeds the allocator's standard block size and is considered a singleton. // Prevent any further allocations on it. block.offset = cast(uintptr)len(block.buffer) } - #no_bounds_check return ptr[:size], nil } - return nil, .Out_Of_Memory } +/* +Resize an allocation owned by rollback stack allocator. +*/ +@(require_results) +rb_resize :: proc( + stack: ^Rollback_Stack, + old_ptr: rawptr, + old_size: int, + size: int, + alignment := DEFAULT_ALIGNMENT, + loc := #caller_location, +) -> (rawptr, Allocator_Error) { + bytes, err := rb_resize_bytes_non_zeroed(stack, byte_slice(old_ptr, old_size), size, alignment, loc) + if bytes != nil { + if old_ptr == nil { + zero_slice(bytes) + } else if size > old_size { + zero_slice(bytes[old_size:]) + } + } + return raw_data(bytes), err +} + +/* +Resize an allocation owned by rollback stack allocator. +*/ +@(require_results) +rb_resize_bytes :: proc( + stack: ^Rollback_Stack, + old_memory: []byte, + size: int, + alignment := DEFAULT_ALIGNMENT, + loc := #caller_location, +) -> ([]u8, Allocator_Error) { + bytes, err := rb_resize_bytes_non_zeroed(stack, old_memory, size, alignment, loc) + if bytes != nil { + if old_memory == nil { + zero_slice(bytes) + } else if size > len(old_memory) { + zero_slice(bytes[len(old_memory):]) + } + } + return bytes, err +} + +/* +Resize an allocation owned by rollback stack allocator without explicit +zero-initialization. +*/ +@(require_results) +rb_resize_non_zeroed :: proc( + stack: ^Rollback_Stack, + old_ptr: rawptr, + old_size: int, + size: int, + alignment := DEFAULT_ALIGNMENT, + loc := #caller_location, +) -> (rawptr, Allocator_Error) { + bytes, err := rb_resize_bytes_non_zeroed(stack, byte_slice(old_ptr, old_size), size, alignment, loc) + return raw_data(bytes), err +} + +/* +Resize an allocation owned by rollback stack allocator without explicit +zero-initialization. +*/ +@(require_results) +rb_resize_bytes_non_zeroed :: proc( + stack: ^Rollback_Stack, + old_memory: []byte, + size: int, + alignment := DEFAULT_ALIGNMENT, + loc := #caller_location, +) -> (result: []byte, err: Allocator_Error) { + old_size := len(old_memory) + ptr := raw_data(old_memory) + assert(size >= 0, "Size must be positive or zero.", loc) + assert(old_size >= 0, "Old size must be positive or zero.", loc) + assert(is_power_of_two(cast(uintptr)alignment), "Alignment must be a power of two.", loc) + if ptr != nil { + if block, _, ok := rb_find_last_alloc(stack, ptr); ok { + // `block.offset` should never underflow because it is contingent + // on `old_size` in the first place, assuming sane arguments. + assert(block.offset >= cast(uintptr)old_size, "Rollback Stack Allocator received invalid `old_size`.") + if block.offset + cast(uintptr)size - cast(uintptr)old_size < cast(uintptr)len(block.buffer) { + // Prevent singleton allocations from fragmenting by forbidding + // them to shrink, removing the possibility of overflow bugs. + if len(block.buffer) <= stack.block_size { + block.offset += cast(uintptr)size - cast(uintptr)old_size + } + #no_bounds_check return (ptr)[:size], nil + } + } + } + result = rb_alloc_bytes_non_zeroed(stack, size, alignment) or_return + runtime.mem_copy_non_overlapping(raw_data(result), ptr, old_size) + err = rb_free(stack, ptr) + return +} + @(private="file", require_results) rb_make_block :: proc(size: int, allocator: Allocator) -> (block: ^Rollback_Stack_Block, err: Allocator_Error) { buffer := runtime.mem_alloc(size_of(Rollback_Stack_Block) + size, align_of(Rollback_Stack_Block), allocator) or_return - block = cast(^Rollback_Stack_Block)raw_data(buffer) #no_bounds_check block.buffer = buffer[size_of(Rollback_Stack_Block):] return } - +/* +Initialize the rollback stack allocator using a fixed backing buffer. +*/ rollback_stack_init_buffered :: proc(stack: ^Rollback_Stack, buffer: []byte, location := #caller_location) { MIN_SIZE :: size_of(Rollback_Stack_Block) + size_of(Rollback_Stack_Header) + size_of(rawptr) assert(len(buffer) >= MIN_SIZE, "User-provided buffer to Rollback Stack Allocator is too small.", location) - block := cast(^Rollback_Stack_Block)raw_data(buffer) block^ = {} #no_bounds_check block.buffer = buffer[size_of(Rollback_Stack_Block):] - stack^ = {} stack.head = block stack.block_size = len(block.buffer) } +/* +Initialize the rollback stack alocator using a backing block allocator. +*/ rollback_stack_init_dynamic :: proc( stack: ^Rollback_Stack, block_size : int = ROLLBACK_STACK_DEFAULT_BLOCK_SIZE, @@ -261,22 +377,25 @@ rollback_stack_init_dynamic :: proc( // size is insufficient; check only on platforms with big enough ints. assert(block_size <= ROLLBACK_STACK_MAX_HEAD_BLOCK_SIZE, "Rollback Stack Allocators cannot support head blocks larger than 2 gigabytes.", location) } - block := rb_make_block(block_size, block_allocator) or_return - stack^ = {} stack.head = block stack.block_size = block_size stack.block_allocator = block_allocator - return nil } +/* +Initialize the rollback stack. +*/ rollback_stack_init :: proc { rollback_stack_init_buffered, rollback_stack_init_dynamic, } +/* +Destroy a rollback stack. +*/ rollback_stack_destroy :: proc(stack: ^Rollback_Stack) { if stack.block_allocator.procedure != nil { rb_free_all(stack) @@ -285,6 +404,37 @@ rollback_stack_destroy :: proc(stack: ^Rollback_Stack) { stack^ = {} } +/* +Rollback stack allocator. + +The Rollback Stack Allocator was designed for the test runner to be fast, +able to grow, and respect the Tracking Allocator's requirement for +individual frees. It is not overly concerned with fragmentation, however. + +It has support for expansion when configured with a block allocator and +limited support for out-of-order frees. + +Allocation has constant-time best and usual case performance. +At worst, it is linear according to the number of memory blocks. + +Allocation follows a first-fit strategy when there are multiple memory +blocks. + +Freeing has constant-time best and usual case performance. +At worst, it is linear according to the number of memory blocks and number +of freed items preceding the last item in a block. + +Resizing has constant-time performance, if it's the last item in a block, or +the new size is smaller. Naturally, this becomes linear-time if there are +multiple blocks to search for the pointer's owning block. Otherwise, the +allocator defaults to a combined alloc & free operation internally. + +Out-of-order freeing is accomplished by collapsing a run of freed items +from the last allocation backwards. + +Each allocation has an overhead of 8 bytes and any extra bytes to satisfy +the requested alignment. +*/ @(require_results) rollback_stack_allocator :: proc(stack: ^Rollback_Stack) -> Allocator { return Allocator { @@ -294,48 +444,37 @@ rollback_stack_allocator :: proc(stack: ^Rollback_Stack) -> Allocator { } @(require_results) -rollback_stack_allocator_proc :: proc(allocator_data: rawptr, mode: Allocator_Mode, - size, alignment: int, - old_memory: rawptr, old_size: int, location := #caller_location, +rollback_stack_allocator_proc :: proc( + allocator_data: rawptr, + mode: Allocator_Mode, + size, alignment: int, + old_memory: rawptr, + old_size: int, + loc := #caller_location, ) -> (result: []byte, err: Allocator_Error) { stack := cast(^Rollback_Stack)allocator_data - switch mode { - case .Alloc, .Alloc_Non_Zeroed: - assert(size >= 0, "Size must be positive or zero.", location) - assert(is_power_of_two(cast(uintptr)alignment), "Alignment must be a power of two.", location) - result = rb_alloc(stack, size, alignment) or_return - - if mode == .Alloc { - zero_slice(result) - } - + case .Alloc: + return rb_alloc_bytes(stack, size, alignment, loc) + case .Alloc_Non_Zeroed: + return rb_alloc_bytes_non_zeroed(stack, size, alignment, loc) case .Free: - err = rb_free(stack, old_memory) - + return nil, rb_free(stack, old_memory) case .Free_All: rb_free_all(stack) - - case .Resize, .Resize_Non_Zeroed: - assert(size >= 0, "Size must be positive or zero.", location) - assert(old_size >= 0, "Old size must be positive or zero.", location) - assert(is_power_of_two(cast(uintptr)alignment), "Alignment must be a power of two.", location) - result = rb_resize(stack, old_memory, old_size, size, alignment) or_return - - #no_bounds_check if mode == .Resize && size > old_size { - zero_slice(result[old_size:]) - } - + return nil, nil + case .Resize: + return rb_resize_bytes(stack, byte_slice(old_memory, old_size), size, alignment, loc) + case .Resize_Non_Zeroed: + return rb_resize_bytes_non_zeroed(stack, byte_slice(old_memory, old_size), size, alignment, loc) case .Query_Features: set := (^Allocator_Mode_Set)(old_memory) if set != nil { set^ = {.Alloc, .Alloc_Non_Zeroed, .Free, .Free_All, .Resize, .Resize_Non_Zeroed} } return nil, nil - case .Query_Info: return nil, .Mode_Not_Implemented } - return } diff --git a/core/mem/tracking_allocator.odin b/core/mem/tracking_allocator.odin index 1b57e5fb4..e436fcb6d 100644 --- a/core/mem/tracking_allocator.odin +++ b/core/mem/tracking_allocator.odin @@ -4,50 +4,85 @@ package mem import "base:runtime" import "core:sync" +/* +Allocation entry for the tracking allocator. + +This structure stores the data related to an allocation. +*/ Tracking_Allocator_Entry :: struct { - memory: rawptr, - size: int, + // Pointer to an allocated region. + memory: rawptr, + // Size of the allocated memory region. + size: int, + // Requested alignment. alignment: int, - mode: Allocator_Mode, - err: Allocator_Error, + // Mode of the operation. + mode: Allocator_Mode, + // Error. + err: Allocator_Error, + // Location of the allocation. location: runtime.Source_Code_Location, } + +/* +Bad free entry for a tracking allocator. +*/ Tracking_Allocator_Bad_Free_Entry :: struct { - memory: rawptr, + // Pointer, on which free operation was called. + memory: rawptr, + // The source location of where the operation was called. location: runtime.Source_Code_Location, } -Tracking_Allocator :: struct { - backing: Allocator, - allocation_map: map[rawptr]Tracking_Allocator_Entry, - bad_free_array: [dynamic]Tracking_Allocator_Bad_Free_Entry, - mutex: sync.Mutex, - clear_on_free_all: bool, - total_memory_allocated: i64, - total_allocation_count: i64, - total_memory_freed: i64, - total_free_count: i64, - peak_memory_allocated: i64, +/* +Tracking allocator data. +*/ +Tracking_Allocator :: struct { + backing: Allocator, + allocation_map: map[rawptr]Tracking_Allocator_Entry, + bad_free_array: [dynamic]Tracking_Allocator_Bad_Free_Entry, + mutex: sync.Mutex, + clear_on_free_all: bool, + total_memory_allocated: i64, + total_allocation_count: i64, + total_memory_freed: i64, + total_free_count: i64, + peak_memory_allocated: i64, current_memory_allocated: i64, } +/* +Initialize the tracking allocator. + +This procedure initializes the tracking allocator `t` with a backing allocator +specified with `backing_allocator`. The `internals_allocator` will used to +allocate the tracked data. +*/ tracking_allocator_init :: proc(t: ^Tracking_Allocator, backing_allocator: Allocator, internals_allocator := context.allocator) { t.backing = backing_allocator t.allocation_map.allocator = internals_allocator t.bad_free_array.allocator = internals_allocator - if .Free_All in query_features(t.backing) { t.clear_on_free_all = true } } +/* +Destroy the tracking allocator. +*/ tracking_allocator_destroy :: proc(t: ^Tracking_Allocator) { delete(t.allocation_map) delete(t.bad_free_array) } +/* +Clear the tracking allocator. -// Clear only the current allocation data while keeping the totals intact. +This procedure clears the tracked data from a tracking allocator. + +**Note**: This procedure clears only the current allocation data while keeping +the totals intact. +*/ tracking_allocator_clear :: proc(t: ^Tracking_Allocator) { sync.mutex_lock(&t.mutex) clear(&t.allocation_map) @@ -56,7 +91,11 @@ tracking_allocator_clear :: proc(t: ^Tracking_Allocator) { sync.mutex_unlock(&t.mutex) } -// Reset all of a Tracking Allocator's allocation data back to zero. +/* +Reset the tracking allocator. + +Reset all of a Tracking Allocator's allocation data back to zero. +*/ tracking_allocator_reset :: proc(t: ^Tracking_Allocator) { sync.mutex_lock(&t.mutex) clear(&t.allocation_map) @@ -70,6 +109,39 @@ tracking_allocator_reset :: proc(t: ^Tracking_Allocator) { sync.mutex_unlock(&t.mutex) } +/* +Tracking allocator. + +The tracking allocator is an allocator wrapper that tracks memory allocations. +This allocator stores all the allocations in a map. Whenever a pointer that's +not inside of the map is freed, the `bad_free_array` entry is added. + +An example of how to use the `Tracking_Allocator` to track subsequent allocations +in your program and report leaks and bad frees: + +Example: + + package foo + + import "core:mem" + import "core:fmt" + + main :: proc() { + track: mem.Tracking_Allocator + mem.tracking_allocator_init(&track, context.allocator) + defer mem.tracking_allocator_destroy(&track) + context.allocator = mem.tracking_allocator(&track) + + do_stuff() + + for _, leak in track.allocation_map { + fmt.printf("%v leaked %m\n", leak.location, leak.size) + } + for bad_free in track.bad_free_array { + fmt.printf("%v allocation %p was freed badly\n", bad_free.location, bad_free.memory) + } + } +*/ @(require_results) tracking_allocator :: proc(data: ^Tracking_Allocator) -> Allocator { return Allocator{ @@ -78,9 +150,14 @@ tracking_allocator :: proc(data: ^Tracking_Allocator) -> Allocator { } } -tracking_allocator_proc :: proc(allocator_data: rawptr, mode: Allocator_Mode, - size, alignment: int, - old_memory: rawptr, old_size: int, loc := #caller_location) -> (result: []byte, err: Allocator_Error) { +tracking_allocator_proc :: proc( + allocator_data: rawptr, + mode: Allocator_Mode, + size, alignment: int, + old_memory: rawptr, + old_size: int, + loc := #caller_location, +) -> (result: []byte, err: Allocator_Error) { track_alloc :: proc(data: ^Tracking_Allocator, entry: ^Tracking_Allocator_Entry) { data.total_memory_allocated += i64(entry.size) data.total_allocation_count += 1 diff --git a/tests/core/mem/test_mem_dynamic_pool.odin b/tests/core/mem/test_mem_dynamic_pool.odin index d1086cfe6..fa204d3b1 100644 --- a/tests/core/mem/test_mem_dynamic_pool.odin +++ b/tests/core/mem/test_mem_dynamic_pool.odin @@ -6,7 +6,7 @@ import "core:mem" expect_pool_allocation :: proc(t: ^testing.T, expected_used_bytes, num_bytes, alignment: int) { pool: mem.Dynamic_Pool - mem.dynamic_pool_init(pool = &pool, alignment = alignment) + mem.dynamic_pool_init(&pool, alignment = alignment) pool_allocator := mem.dynamic_pool_allocator(&pool) element, err := mem.alloc(num_bytes, alignment, pool_allocator) @@ -48,7 +48,7 @@ expect_pool_allocation_out_of_band :: proc(t: ^testing.T, num_bytes, out_band_si testing.expect(t, num_bytes >= out_band_size, "Sanity check failed, your test call is flawed! Make sure that num_bytes >= out_band_size!") pool: mem.Dynamic_Pool - mem.dynamic_pool_init(pool = &pool, out_band_size = out_band_size) + mem.dynamic_pool_init(&pool, out_band_size = out_band_size) pool_allocator := mem.dynamic_pool_allocator(&pool) element, err := mem.alloc(num_bytes, allocator = pool_allocator)