Reorganize package mem

This commit is contained in:
gingerBill
2019-02-10 22:15:34 +00:00
parent 6a0c3d5599
commit 53d8216311
3 changed files with 628 additions and 664 deletions
+4 -389
View File
@@ -183,27 +183,13 @@ align_forward_uintptr :: proc(ptr, align: uintptr) -> uintptr {
return uintptr(p);
}
Allocation_Header :: struct {size: int};
allocation_header_fill :: proc(header: ^Allocation_Header, data: rawptr, size: int) {
header.size = size;
ptr := cast(^uint)(ptr_offset(header, 1));
n := ptr_sub(cast(^uint)data, ptr);
for i in 0..n-1 {
ptr_offset(ptr, i)^ = ~uint(0);
}
}
allocation_header :: proc(data: rawptr) -> ^Allocation_Header {
if data == nil do return nil;
p := cast(^uint)data;
for ptr_offset(p, -1)^ == ~uint(0) do p = ptr_offset(p, -1);
return (^Allocation_Header)(ptr_offset(p, -1));
context_from_allocator :: proc(a: Allocator) -> type_of(context) {
context.allocator = a;
return context;
}
Fixed_Byte_Buffer :: distinct [dynamic]byte;
make_fixed_byte_buffer :: proc(backing: []byte) -> Fixed_Byte_Buffer {
@@ -218,110 +204,6 @@ make_fixed_byte_buffer :: proc(backing: []byte) -> Fixed_Byte_Buffer {
// Custom allocators
Arena :: struct {
backing: Allocator,
memory: Fixed_Byte_Buffer,
temp_count: int,
}
Arena_Temp_Memory :: struct {
arena: ^Arena,
original_count: int,
}
init_arena_from_memory :: proc(using a: ^Arena, data: []byte) {
backing = Allocator{};
memory = make_fixed_byte_buffer(data);
temp_count = 0;
}
init_arena_from_context :: proc(using a: ^Arena, size: int) {
backing = context.allocator;
memory = make_fixed_byte_buffer(make([]byte, size));
temp_count = 0;
}
context_from_allocator :: proc(a: Allocator) -> type_of(context) {
context.allocator = a;
return context;
}
destroy_arena :: proc(using a: ^Arena) {
if backing.procedure != nil {
context.allocator = backing;
if memory != nil {
free(&memory[0]);
}
memory = nil;
}
}
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, flags: u64, location := #caller_location) -> rawptr {
using Allocator_Mode;
arena := cast(^Arena)allocator_data;
switch mode {
case Alloc:
total_size := size + alignment;
if len(arena.memory) + total_size > cap(arena.memory) {
return nil;
}
#no_bounds_check end := &arena.memory[len(arena.memory)];
ptr := align_forward(end, uintptr(alignment));
(^Raw_Slice)(&arena.memory).len += total_size;
return zero(ptr, size);
case Free:
// NOTE(bill): Free all at once
// Use Arena_Temp_Memory if you want to free a block
case Free_All:
(^Raw_Slice)(&arena.memory).len = 0;
case Resize:
return default_resize_align(old_memory, old_size, size, alignment, arena_allocator(arena));
}
return nil;
}
begin_arena_temp_memory :: proc(a: ^Arena) -> Arena_Temp_Memory {
tmp: Arena_Temp_Memory;
tmp.arena = a;
tmp.original_count = len(a.memory);
a.temp_count += 1;
return tmp;
}
end_arena_temp_memory :: proc(using tmp: Arena_Temp_Memory) {
assert(len(arena.memory) >= original_count);
assert(arena.temp_count > 0);
(^Raw_Dynamic_Array)(&arena.memory).len = original_count;
arena.temp_count -= 1;
}
align_formula :: proc(size, align: int) -> int {
result := size + align-1;
return result - result%align;
@@ -350,270 +232,3 @@ calc_padding_with_header :: proc(ptr: uintptr, align: uintptr, header_size: int)
}
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,
}
init_stack :: proc(s: ^Stack, data: []byte) {
s.data = data;
s.prev_offset = 0;
s.curr_offset = 0;
s.peak_used = 0;
}
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, flags: u64, location := #caller_location) -> rawptr {
using Allocator_Mode;
s := cast(^Stack)allocator_data;
if s.data == nil {
return nil;
}
raw_alloc :: proc(s: ^Stack, size, alignment: int) -> rawptr {
curr_addr := uintptr(&s.data[0]) + 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;
}
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 = auto_cast padding;
header.prev_offset = auto_cast s.prev_offset;
s.curr_offset += size;
s.peak_used = max(s.peak_used, s.curr_offset);
return zero(rawptr(next_addr), size);
}
switch mode {
case Alloc:
return raw_alloc(s, size, alignment);
case Free:
if old_memory == nil {
return nil;
}
start := uintptr(&s.data[0]);
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;
}
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(&s.data[0]));
if old_offset != int(header.prev_offset) {
panic("Out of order stack allocator free");
return nil;
}
s.curr_offset = int(old_offset);
s.prev_offset = int(header.prev_offset);
case Free_All:
s.prev_offset = 0;
s.curr_offset = 0;
case Resize:
if old_memory == nil {
return raw_alloc(s, size, alignment);
}
if size == 0 {
return nil;
}
start := uintptr(&s.data[0]);
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;
}
if curr_addr >= start+uintptr(s.curr_offset) {
// NOTE(bill): Allow double frees
return nil;
}
if old_size == size {
return old_memory;
}
header := (^Stack_Allocation_Header)(curr_addr - size_of(Stack_Allocation_Header));
old_offset := int(curr_addr - uintptr(header.padding) - uintptr(&s.data[0]));
if old_offset != int(header.prev_offset) {
ptr := raw_alloc(s, size, alignment);
copy(ptr, old_memory, min(old_size, size));
return ptr;
}
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 old_memory;
}
return nil;
}
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,
}
init_small_stack :: proc(s: ^Small_Stack, data: []byte) {
s.data = data;
s.offset = 0;
s.peak_used = 0;
}
small_stack_allocator :: proc(stack: ^Small_Stack) -> Allocator {
return Allocator{
procedure = small_stack_allocator_proc,
data = stack,
};
}
small_stack_allocator_proc :: proc(allocator_data: rawptr, mode: Allocator_Mode,
size, alignment: int,
old_memory: rawptr, old_size: int, flags: u64, location := #caller_location) -> rawptr {
using Allocator_Mode;
s := cast(^Small_Stack)allocator_data;
if s.data == nil {
return nil;
}
raw_alloc :: proc(s: ^Small_Stack, size, alignment: int) -> rawptr {
curr_addr := uintptr(&s.data[0]) + 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;
}
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 zero(rawptr(next_addr), size);
}
switch mode {
case Alloc:
return raw_alloc(s, size, alignment);
case Free:
if old_memory == nil {
return nil;
}
start := uintptr(&s.data[0]);
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;
}
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(&s.data[0]));
s.offset = int(old_offset);
case Free_All:
s.offset = 0;
case Resize:
if old_memory == nil {
return raw_alloc(s, size, alignment);
}
if size == 0 {
return nil;
}
start := uintptr(&s.data[0]);
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;
}
if curr_addr >= start+uintptr(s.offset) {
// NOTE(bill): Treat as a double free
return nil;
}
if old_size == size {
return old_memory;
}
ptr := raw_alloc(s, size, alignment);
copy(ptr, old_memory, min(old_size, size));
return ptr;
}
return nil;
}