// Test whether profiling signals are sent to the thread
// whose execution triggered the signal.

#include <sys/time.h>
#include <sys/signal.h>
#include <pthread.h>
#include <unistd.h>
#include <stdlib.h>
#include <stdio.h>
#include <string.h>

static void handler(int);
static void* looper(void*);

enum {
	Nthread = 4,
};

static pthread_t pmain, ploop[Nthread];
static int maincount, loopcount[Nthread];

int
main(void)
{
	int i;
	struct itimerval it;
	struct sigaction sa;
	pthread_cond_t cond;
	pthread_mutex_t mu;

	memset(&sa, 0, sizeof sa);
	sa.sa_handler = handler;
	sa.sa_flags = SA_RESTART;
	memset(&sa.sa_mask, 0xff, sizeof sa.sa_mask);
	sigaction(SIGPROF, &sa, 0);

	pmain = pthread_self();
	for(i=0; i<Nthread; i++)
		pthread_create(&ploop[i], 0, looper, 0);

	memset(&it, 0, sizeof it);
	it.it_interval.tv_usec = 10000;
	it.it_value = it.it_interval;
	setitimer(ITIMER_PROF, &it, 0);

	pthread_mutex_init(&mu, 0);
	pthread_mutex_lock(&mu);

	pthread_cond_init(&cond, 0);
	for(;;)
		pthread_cond_wait(&cond, &mu);

	return 0;
}

static void
handler(int sig)
{
	static volatile int nsig;
	pthread_t p;
	int i, n;

	p = pthread_self();
	if(p == pmain) {
		if(nsig < 5)
			printf("signal on sleeping main thread\n");
		maincount++;
	} else {
	    for(i = 0; i < Nthread; i++) {
		if(p == ploop[i]) {
		    if(nsig < 5)
		    	printf("signal on cpu-chewing looper thread %d\n", i);
		    loopcount[i]++;
		    break;
		}
	    }
	    if(i == 4)
		printf("signal on unknown thread %p\n", (void*)p);
	}
	n = nsig;
	n++;
	nsig = n;
	if(n == 5)
		printf("... still running but not printing signals ...\n");
	if(n == 500) {
		printf("%d signals received.\n", nsig);
		printf("%d on main\n", maincount);
		for(i = 0; i < Nthread; i++)
			printf("%d on looper %d\n", loopcount[i], i);
		exit(0);
	}
}

static void*
looper(void *v)
{
	for(;;);
}