dmmlib/src/sll/first_fit_on_freelist.c

#include "sll/first_fit_on_freelist.h"
#include "block_header.h"

/**
 * \details In order to remove a block from a singly linked list, we need to
 * keep track of the previous block as well: The previous block must point to
 * the current block's next block once the current one is removed.
 */
void * first_fit_on_freelist(heap_t *heap, size_t requested_size) {
    void *current_block, *previous_block, *ptr;

    ptr = NULL;

    for(current_block = heap->free_list_head; current_block != NULL;
            current_block = get_next(current_block)) {
        if(get_size(current_block) >= requested_size) {
            if(current_block == heap->free_list_head) {
                heap->free_list_head = get_next(current_block);
            } else {
                set_next(previous_block, get_next(current_block));
            }
            ptr = current_block;
            break;
        }
        previous_block = current_block;
    } 

    return ptr;
}