Files
metadesk/code/base/arena.h
T
2025-02-05 10:37:25 -05:00

83 lines
2.3 KiB
C

#ifdef INTELLISENSE_DIRECTIVES
# pragma once
# include "macros.h"
# include "base_types.h"
#endif
// Copyright (c) 2024 Epic Games Tools
// Licensed under the MIT license (https://opensource.org/license/mit/)
////////////////////////////////
//~ rjf: Constants
#define MD_ARENA_HEADER_SIZE 64
////////////////////////////////
//~ rjf: Types
typedef U32 ArenaFlags;
enum
{
ArenaFlag_NoChain = ( 1 << 0),
ArenaFlag_LargePages = ( 1 << 1),
};
typedef struct ArenaParams ArenaParams;
struct ArenaParams
{
ArenaFlags flags;
U64 reserve_size;
U64 commit_size;
void* optional_backing_buffer;
};
typedef struct Arena Arena;
struct Arena
{
Arena* prev; // previous arena in chain
Arena* current; // current arena in chain
ArenaFlags flags;
U32 cmt_size;
U64 res_size;
U64 base_pos;
U64 pos;
U64 cmt;
U64 res;
};
static_assert(sizeof(Arena) <= MD_ARENA_HEADER_SIZE, "sizeof(Arena) <= MD_ARENA_HEADER_SIZE");
typedef struct TempArena TempArena;
struct TempArena
{
Arena* arena;
U64 pos;
};
////////////////////////////////
//~ rjf: Arena Functions
//- rjf: arena creation/destruction
internal Arena* arena_alloc_(ArenaParams *params);
#define arena_alloc(...) arena_alloc_( & ( ArenaParams) { .reserve_size = MB(64), .commit_size = KB(64), __VA_ARGS__ } )
internal void arena_release(Arena *arena);
//- rjf: arena push/pop/pos core functions
internal void *arena_push (Arena *arena, U64 size, U64 align);
internal U64 arena_pos (Arena *arena);
internal void arena_pop_to(Arena *arena, U64 pos);
//- rjf: arena push/pop helpers
internal void arena_clear(Arena *arena);
internal void arena_pop (Arena *arena, U64 amt);
//- rjf: temporary arena scopes
internal TempArena temp_arena_begin(Arena *arena);
internal void temp_arena_end(TempArena temp);
//- rjf: push helper macros
#define push_array_no_zero_aligned(a, T, c, align) (T *)arena_push((a), sizeof(T) * (c), (align))
#define push_array_aligned(a, T, c, align) (T *)memory_zero(push_array_no_zero_aligned(a, T, c, align), sizeof(T) * (c))
#define push_array_no_zero(a, T, c) push_array_no_zero_aligned(a, T, c, max(8, align_of(T)))
#define push_array(a, T, c) push_array_aligned (a, T, c, max(8, align_of(T)))