/*
 * Copyright (c) 2006 Daniel M. Eischen <eischen@vigrid.com>
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Neither the name of the author nor the names of any co-contributors
 *    may be used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY DANIEL M. EISCHEN AND CONTRIBUTORS ``AS IS''
 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 *
 * $Id$
 */

/*
 * gcc -Wall -D_POSIX_PTHREAD_SEMANTICS -o test_sigwaitone test_sigwaitone.c -lpthread
 */
#include <stdlib.h>
#include <unistd.h>

#include <errno.h>
#include <pthread.h>
#include <signal.h>
#include <stdio.h>
#include <string.h>

static int		sigcount = 0;
static pthread_mutex_t	waiter_mutex;
static volatile int	done = 0;
static char		*progname = NULL;


static void
usage(void)
{
	fprintf(stderr, "Usage: %s sig [sig] ...\n", progname);
	exit (1);
}

static void *
sigwaiter(void *arg)
{
	int signo;
	sigset_t mask;
	sigset_t waitmask;

	/* Initially block everything. */
	sigfillset(&mask);
	sigprocmask(SIG_SETMASK, &mask, NULL);

	/* Wait for any signal. */
	sigemptyset(&waitmask);
	sigfillset(&waitmask);

	while (done == 0) {
		if (sigwait(&waitmask, &signo) != 0) {
			fprintf (stderr,
			    "Unable to wait for signal, errno %d\n",
			    errno);
			exit (1);
		}
		sigcount++;
		fprintf (stderr, "Sigwait caught signal %d\n", signo);

		/*
		 * Allow the main thread to suspend the thread in
		 * order to test pending signals.
		 */
		pthread_mutex_lock (&waiter_mutex);
		pthread_mutex_unlock (&waiter_mutex);
	}
	pthread_exit(arg);
	return (NULL);
}


static void
send_process_signal (int signo)
{
	if (kill(getpid (), signo) != 0) {
		fprintf (stderr, "Unable to send process signal, errno %d.\n",
		    errno);
		exit (1);
	}
}


int
main(int argc, char *argv[])
{
	pthread_mutexattr_t mattr;
	pthread_attr_t	pattr;
	pthread_t	tid;
	void *		exit_status;
	sigset_t	set;
	char		junk;
	int		signo;
	int		i;

	progname = argv[0];

	if (argc == 1)
		usage();

	/*
	 * Initialize the thread attribute.
	 */
	if ((pthread_attr_init(&pattr) != 0) ||
	    (pthread_attr_setdetachstate(&pattr,
	    PTHREAD_CREATE_JOINABLE) != 0)) {
		fprintf(stderr, "Unable to initialize thread attributes.\n");
		exit(1);
	}

	/*
	 * Initialize and create a mutex.
	 */
	if ((pthread_mutexattr_init(&mattr) != 0) ||
	    (pthread_mutex_init(&waiter_mutex, &mattr) != 0)) {
		fprintf(stderr, "Unable to create waiter mutex.\n");
		exit(1);
	}

	/*
	 * Create the sigwaiter thread and allow it to start.
	 */
	if (pthread_create(&tid, &pattr, sigwaiter, NULL) != 0) {
		fprintf(stderr, "Unable to create thread.\n");
		exit(1);
	}
	sleep(1);

	for (i = 1; i < argc; i++) {
		if (sscanf(argv[i], "%d%c", &signo, &junk) != 1)
			usage();
		/*
		 * Block the signal from the main (this) thread.
		 */
		sigemptyset(&set);
		sigaddset(&set, signo);
		sigprocmask(SIG_BLOCK, &set, NULL);

		/* Send the signal which should release the sigwait. */
		sigcount = 0;
		send_process_signal(signo);
		sleep(1);
		if (sigcount != 1)
			fprintf(stderr,
			    "FAIL: sigwait doesn't wake up for signal %d.\n",
			    signo);
	}

	done = 1;
	pthread_kill(tid, SIGHUP);

	/*
	 * Wait for the thread to finish.
	 */
	pthread_join(tid, &exit_status);

	return (0);
}