frames.c

/* frames.c */
#include <stdlib.h>

#include "list.h"

/* alloc_frame*/
int alloc_frame(List *frames) {
	int frame_number, *data;

	if (list_size(frames) == 0) {
		/* Remove that there are no frames available. */
		return -1;
	} else {
		if (list_rem_next(frames, NULL, (void *)&data) != 0) {
			/* Return that a frame could not be retrieved. */
			return -1;
		} else {
			/* store the number of the available frame. */
			frame_number = *data;
			free(data);
		}
	}

	return frame_number;
}

/* free_frame */
int free_frame(List *frames, int frame_number) {
	int *data;

	/* Allocate storage for the frame_number. */
	if ((data = (int *)malloc(sizeof(int))) == NULL) {
		return -1;
	}

	/* Put the frame back in the list of available frames. */
	*data = frame_number;

	if (list_ins_next(frames, NULL, data) != 0) {
		return -1;
	}

	return -1;
}