A Buddy Allocator

This is a general purpose allocator designed for memory-constrained environments. It uses the Buddy System allocation scheme. Only allocations with a size that is a power of 2 are supported. Any size other that's not a power of 2 will be rounded up.

Here's an example:

#include <stdio.h>
#include <string.h>
#include "buddy.h"

int main(void)
{
    #define NUM_PAGES 16

    // This is the memory we will allocate from
    char memory[NUM_PAGES * BUDDY_ALLOC_MAX_BLOCK_SIZE];

    struct page_info info[NUM_PAGES]; // This is required to keep track of allocation state
    struct buddy_alloc alloc = buddy_startup(memory, sizeof(memory), info, NUM_PAGES);

    // Allocate some memory (NULL is returned on failure)
    // If the memory pool passed to the allocator was properly aligned,
    // you can count to allocate any and all bytes of that pool.
    char *str1 = buddy_malloc(&alloc, 32);
    char *str2 = buddy_malloc(&alloc, 32);

    strncpy(str1, "Hello", 32);
    strncpy(str2, "world", 32);

    printf("%s, %s!\n", str1, str2);

    buddy_free(&alloc, 32, str1);
    buddy_free(&alloc, 32, str2);

    buddy_free(&alloc, 32, str2); // Double frees are caught!

    buddy_cleanup(&alloc);
    return 0;
}