/* $Id: mtxloop.c,v 1.2 2012/09/21 10:27:27 kostik Exp kostik $ */

#include <sys/types.h>
#include <err.h>
#include <pthread.h>
#include <signal.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <machine/atomic.h>

#define THRN	10

static unsigned long counter;

static void
siginfo_handler(int signo __unused)
{
}

static void *
worker(void *arg)
{
	pthread_mutex_t *mtx;
	int error;

	mtx = arg;
	for (;;) {
		error = pthread_mutex_lock(mtx);
		if (error != 0)
			errc(1, error, "pthread_mutex_lock");
		error = pthread_mutex_unlock(mtx);
		if (error != 0)
			errc(1, error, "pthread_mutex_unlock");
		atomic_add_long(&counter, 1);
	}
	return (NULL);
}

int
main(void)
{
	pthread_t t[THRN];
	pthread_mutex_t mtx;
	sigset_t sigs;
	struct sigaction sa;
	int error, i, sig;

	bzero(&sa, sizeof(sa));
	sa.sa_handler = siginfo_handler;
	if (sigaction(SIGINFO, &sa, NULL) == -1)
		err(1, "sigaction");
	sigemptyset(&sigs);
	sigaddset(&sigs, SIGINFO);
	sigaddset(&sigs, SIGTERM);
	sigaddset(&sigs, SIGINT);
	error = pthread_sigmask(SIG_BLOCK, &sigs, NULL);
	if (error != 0)
		errc(1, error, "pthread_sigmask");

	error = pthread_mutex_init(&mtx, NULL);
	if (error != 0)
		errc(1, error, "pthread_mutex_init");
	for (i = 0; i < THRN; i++) {
		error = pthread_create(&t[i], NULL, worker, &mtx);
		if (error != 0)
			errc(1, error, "pthread_create %d", i);
	}
	
	for (;;) {
		error = sigwait(&sigs, &sig);
		if (error != 0)
			errc(1, error, "sigwait");
		switch (sig) {
		case SIGINFO:
			printf("Loop counter %lu\n", counter);
			break;
		default:
			return (0);
		}
	}
	return (0);
}