CAllocator

CAllocator (short for "CAlloc") is a general-purpose sequential-fit memory allocator written in C (hence the name "C Allocator").

Contents

• API
• Usage Example
• License

API

void cinit(CAllocator *allocator, void *memory, size_t capacity);
void *c_alloc(CAllocator *allocator, size_t size);
void cfree(CAllocator *allocator, void *ptr);
void *crealloc(CAllocator *allocator, void *ptr, size_t size);
void creset(CAllocator *allocator);
void cdestroy(CAllocator *allocator);

• cinit — initializes the allocator over the given memory region. The arena must be aligned to CA_ALIGNMENT. When memory == NULL and the capacity is sufficient, the allocator allocates the initial region itself and can grow as needed.
• c_alloc — allocates a block of at least size bytes; returns NULL when the arena is exhausted (external) or when growth is not possible.
• cfree — frees a block previously returned by c_alloc or crealloc; NULL and double free are ignored.
• crealloc — resizes a block: grows in place when possible, otherwise allocates a new block and copies the contents. On failure the original block is left untouched.
• creset — returns the arena to its initial state (a single free block spanning the whole region).
• cdestroy — frees the region and shuts down the allocator. Required for self-owned arenas; for external ones it only resets the state.

Usage Example

#include <calloc.h>

static unsigned char arena_memory[256 * 1024];

int main(void) {
    CAllocator arena;
    cinit(&arena, arena_memory, sizeof(arena_memory));

    void *p = c_alloc(&arena, 1024);
    p = crealloc(&arena, p, 2048);
    cfree(&arena, p);
    creset(&arena);
}

There are two ways to use the allocator: copy src/calloc.h and src/calloc.c directly into your project, or link against the prebuilt static library.

Build and Verify

Requires xmake:

xmake f -m release
xmake build

Apache License 2.0 — see LICENSE.