#include <unistd.h>
#include <stdio.h>
#include <errno.h>
#include <string.h>
#ifdef HAVE_LOCKS
#include "posix_lock.h"
#endif /* HAVE_LOCKS */
#include "other.h"
#include "sys_alloc.h"
#include "block_header.h"
#include "heap.h"

void *sys_alloc(heap_t *heap, size_t size) {
    size_t allocation_size;
    void *ptr;

#ifdef HAVE_LOCKS
    sbrk_lock();
#endif /* HAVE_LOCKS */

    allocation_size = req_padding(size) + HEADER_SIZE;

    ptr = sbrk((int) allocation_size);
    if(ptr == (void *) -1) {
        printf("sbrk problem for size of: %zu\n", allocation_size);
        printf( "Error on sbrk: %s\n", strerror( errno ) );
    }
    ptr = (void *) ((char *) ptr + HEADER_SIZE);

    set_size(ptr, req_padding(size));
    set_requested_size(ptr, size);
    set_next(ptr, heap->used_blocks_head);	
    heap->used_blocks_head = ptr;

#ifdef HAVE_LOCKS
    sbrk_unlock();
#endif /* HAVE_LOCKS */

    return  ptr;
}