#define INVOCATIONS(n)	static int _invocations = 0; \
			if (_invocations++ % (n) ? 0 : (_invocations = 1))

#define PROP_GRANULARITY 10000 /* 1ms */
#define NBUCKETS (1000000/PROP_GRANULARITY)

void prop_collect_stats(struct buf *new)
{
	/* cscan_collect_stats is a prerequisite and should be called first */
}

#define pprintf(x...) do { } while(0)
/* #define pprintf printf */

int prop_evaluate(volatile struct buf *last, volatile struct buf *next)
{
	quad_t wait[NRC], tot_wait = 0;
	int i, all_okay = 1;
	struct proc *p;

	quad_t minstart = QUAD_MAX;
	for (i = 0; i < NRC; i++) {
		if (rc[i].pending) {
			if (rc[i].start < minstart)
				minstart = rc[i].start;
		}
	}

#define falling_behind(r) (r.start + thresh(r) < minstart)
#define stt bpinfo(next).rc, (state == IDLE ? "idle" : state == WAIT ? "wait" : "busy")

	for (i = 0; i < NRC; i++) if (falling_behind(rc[i]))
		pprintf("behind %d ", i);
	pprintf("\n");

	if (falling_behind(RC(next))) { /* if that can happen */
		pprintf("[%d] %s: 0: self falling behind\n", stt);
		return 0;
	}

	for (i = 0; i < NRC; i++) if (falling_behind(rc[i])) all_okay = 0;
	if (all_okay) {
		pprintf("[%d] %s: 0: nobody falling behind\n", stt);
		return 0;
	}

	for (i = 0; i < NRC; i++) wait[i] = QUAD_MAX;

#define pentity (*pinfo(p))
	LIST_FOREACH(p, &allproc, p_list) {
		i = pinfo(p)->rc;
		if (falling_behind(rc[i])) {
			if (pentity.expected_thinktime < 0
			    || pentity.expected_thinktime > 9*MAXTIME/10)
				continue;
			pprintf("<%d> mostthinktime = %lld\n", i, pentity.expected_most_thinktime);
			wait[i] = qmin(wait[i], pentity.expected_most_thinktime);
		}
	}

	tot_wait = QUAD_MAX;
	for (i = 0; i < NRC; i++) {
		/* if (wait[i] == QUAD_MAX) wait[i] = -1; */
		pprintf("wait<%d>:%lld ", i, wait[i]);
		tot_wait = qmin(tot_wait, wait[i]);
	}
	if (tot_wait == QUAD_MAX) tot_wait = -1;
	pprintf("\n");
	if (tot_wait < 0)
		pprintf("[%d] %s: -1: hopeless\n", stt);
	else
		pprintf("[%d] %s: %lld: wait\n", stt, tot_wait);
	return tot_wait;
}