Arena.h

Arena allocator.

License: GPL-3.0-or-later.

cbuild_arena_t

typedef struct cbuild_arena_t {
void* base;
size_t capacity;
size_t pointer;
#ifdef CBUILD_PROFILER
size_t max_pointer;
#endif // CBUILD_PROFILER
} cbuild_arena_t;

Arena allocator state.

Arena automatically pad things to 2 * sizeof(void*). This is done to be a little more cache-friendly. Padding is done after allocation so it is always placed after the data.

void* base Base pointer for allocated memory.
size_t capacity Capacity of this arena.
size_t pointer Pointer to first unallocated byte.

cbuild_arena_base_realloc

CBUILDDEF void cbuild_arena_base_realloc(cbuild_arena_t* arena, size_t new_capacity);

Reallocate arena base to new size.

If old base is NULL then new memory will be allocated.

This is just a direct call to realloc plus some metadata management.

cbuild_arena_base_malloc

#define cbuild_arena_base_malloc(arena, capacity)

Allocate new arena base.

cbuild_arena_t* arena Arena object.
size_t capacity Capacity of arena.

cbuild_arena_malloc

CBUILDDEF void* cbuild_arena_malloc(cbuild_arena_t* arena, size_t size);

Allocate inside of arena.

cbuild_arena_t* arena Arena object.
size_t size Number of bytes to allocate.

void* Pointer into arena. NULL if out-of-memory.

cbuild_arena_realloc

CBUILDDEF void* cbuild_arena_realloc(cbuild_arena_t* arena, void* ptr, size_t size);

realloc for arena. Will not free old memory.

It sizesize_t is bigger than old size then memory from adjacent allocations will be used to initialize new memory block. This is safe access (no segmentation fault possible), but can expose unrelated memory trough new allocation.

cbuild_arena_checkpoint

CBUILDDEF size_t cbuild_arena_checkpoint(cbuild_arena_t* arena);

Save checkpoint into arena.

cbuild_arena_reset

CBUILDDEF void cbuild_arena_reset(cbuild_arena_t* arena, size_t checkpoint);

Reset arena to some checkpoint.

cbuild_arena_free

#define cbuild_arena_free(arena)

Free arena. Set pointer to 0.

cbuild_arena_t* arena Arena object.

cbuild_arena_strdup

CBUILDDEF char* cbuild_arena_strdup(cbuild_arena_t* arena, const char* src);

strdup that uses arena as allocator.

cbuild_arena_memdup

CBUILDDEF void* cbuild_arena_memdup(cbuild_arena_t* arena, const void* src, size_t n);

memdup that uses arena as its allocator.

cbuild_arena_sprintf

CBUILDDEF char* cbuild_arena_sprintf(cbuild_arena_t* arena, const char* fmt, ...);

sprintf that uses arena as its allocator.

cbuild_arena_vsprintf

CBUILDDEF char* cbuild_arena_vsprintf(cbuild_arena_t* arena, const char* fmt,
va_list args);

vsprintf that uses arena as its allocator.

Arena allocator profiles

This adds one size_t field to each arena that track maximum allocated size. This makes each allocation a little slower.

cbuild_arena_profiler Just prints usage as TRACE log.