"Free list" example

freelist.c

/*
 * http://en.wikipedia.org/wiki/Free_list
 * This code in the public domain under Creative Commons CC0 1.0 Universal Public Domain Dedication:
 * http://creativecommons.org/publicdomain/zero/1.0/
 */

typedef struct free_list_node {
	void* memory;
	size_t size;
	struct free_list_node* next;
} free_list_node;

static free_list_node* free_list = NULL;

void* free_list_alloc(size_t size) {
	free_list_node* foundnode;
	void* memoryptr;
	/* Do stuff
	 * ...
	 * Assume that we've found/created a node with a memory block large enough
	 * and put a pointer to it in "foundnode".
	 */
	memoryptr = foundnode->memory;
	/* Delete the node from the list.
	 * ...
	 */
	return memoryptr;
}

void free_list_free(void* memory) {
	free_list_node* returnednode;
	returnednode = malloc(sizeof(*returnednode));
	if(!returnednode) {
		/* Handle allocation falure... */
	} else {
		/* Add the node to the list... */
	}
}