#include <unistd.h>
#include <stdio.h>
#include <errno.h>
#include <string.h>
#include "posix_lock.h"
#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;

	sbrk_lock();

	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;

	sbrk_unlock();

	return  ptr;
}