From 4b9ab2ec5acf2ecf2e96c38733a835b964664171 Mon Sep 17 00:00:00 2001 From: Omniscient <17525998+omnisci3nce@users.noreply.github.com> Date: Sun, 25 Feb 2024 11:02:46 +1100 Subject: add an arena allocator first impl --- src/std/mem.c | 26 ++++++++++++++++++++++++++ 1 file changed, 26 insertions(+) create mode 100644 src/std/mem.c (limited to 'src/std/mem.c') diff --git a/src/std/mem.c b/src/std/mem.c new file mode 100644 index 0000000..c30f76d --- /dev/null +++ b/src/std/mem.c @@ -0,0 +1,26 @@ +#include "mem.h" +#include +#include +#include +#include "log.h" + +#ifndef DEFAULT_ALIGNMENT +#define DEFAULT_ALIGNMENT (2 * sizeof(void*)) +#endif + +void* arena_alloc_align(arena* a, size_t size, size_t align) { + ptrdiff_t padding = -(uintptr_t)a->begin & (align - 1); + ptrdiff_t available = a->end - a->begin - padding; + TRACE("Padding %td available %td", padding, available); + if (available < 0 || (ptrdiff_t)size > available) { + ERROR_EXIT("Arena ran out of memory\n"); + } + void* p = a->begin + padding; + a->begin += padding + size; + return memset(p, 0, size); +} +void* arena_alloc(arena* a, size_t size) { return arena_alloc_align(a, size, DEFAULT_ALIGNMENT); } + +arena arena_create(void* backing_buffer, size_t capacity) { + return (arena){ .begin = backing_buffer, .end = backing_buffer + (ptrdiff_t)capacity }; +} \ No newline at end of file -- cgit v1.2.3-70-g09d2