adreuter / mempool

A fast memory pool allocator

mempool

Description

mempool is a tiny static C-library providing a minimal and efficient implementation of a memory pool. For more information on memory pool based allocation see this Wikipedia Page

Usage

#include <stddef.h>
#include <stdio.h>
#include <stdlib.h>

#include "mempool.h"

int main(void)
{
    size_t bc = 8;    // block count
    size_t bs = 512;  // block size
    mp_pool_t mp;

    // first we need to allocate the pool memory on the heap
    void *m = malloc(bc * bs);
    if(!m) {
        return -1;
    }

    // initialize mp
    mp_init(bs, bc, m, &mp);

    // now we can request blocks from the pool using mp_malloc
    // and free blocks using mp_free

    // free the pool's memory after we don't need it anymore
    free(m);
    return 0;
}

Documentation

Types

mp_pool_t

This type represents the memory pool.

Functions

int mp_init(size_t bs, size_t bc, void *m, mp_pool_t *mp)

Initializes the memory pool given blocksize bs, blockcount bc and a pointer m to a piece of memory of minimum size bc * bs. bs is required to be at least sizeof(size_t). Otherwise it returns -1. Guaranteed to run in constant time.

void *mp_malloc(mp_pool_t *mp)

Returns a pointer to a free block in the memory pool. If no free blocks are left it will return NULL. Guaranteed to run in constant time.

void mp_free(mp_pool_t *mp, void *b)

Adds b to the list of free blocks. Guaranteed to run in constant time.

Dependencies

stddef.h

License

MIT License

Copyright (c) 2021 Adrian Reuter

Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.