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/* $OpenBSD: sigsuspend.c,v 1.1 2001/08/15 14:37:13 fgsch Exp $ */
/*
* Copyright (c) 1998 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. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. All advertising materials mentioning features or use of this software
* must display the following acknowledgement:
* This product includes software developed by Daniel M. Eischen.
* 4. 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.
*
*/
#include <stdlib.h>
#include <unistd.h>
#include <errno.h>
#include <pthread.h>
#include <signal.h>
#include <stdio.h>
#include <string.h>
#include <pthread_np.h>
#include "test.h"
static int sigcounts[NSIG + 1];
static int sigfifo[NSIG + 1];
static int fifo_depth = 0;
static sigset_t suspender_mask;
static pthread_t suspender_tid;
static void *
sigsuspender (void *arg)
{
int save_count, status, i;
sigset_t run_mask;
SET_NAME("sigsuspender");
/* Run with all signals blocked. */
sigfillset (&run_mask);
CHECKe(sigprocmask (SIG_SETMASK, &run_mask, NULL));
/* Allow these signals to wake us up during a sigsuspend. */
sigfillset (&suspender_mask); /* Default action */
sigdelset (&suspender_mask, SIGINT); /* terminate */
sigdelset (&suspender_mask, SIGHUP); /* terminate */
sigdelset (&suspender_mask, SIGQUIT); /* create core image */
sigdelset (&suspender_mask, SIGURG); /* ignore */
sigdelset (&suspender_mask, SIGIO); /* ignore */
sigdelset (&suspender_mask, SIGUSR2); /* terminate */
while (sigcounts[SIGINT] == 0) {
save_count = sigcounts[SIGUSR2];
status = sigsuspend (&suspender_mask);
if ((status == 0) || (errno != EINTR)) {
DIE(errno, "Unable to suspend for signals, "
"return value %d\n",
status);
}
for (i = 0; i < fifo_depth; i++)
printf ("Sigsuspend woke up by signal %d (%s)\n",
sigfifo[i], strsignal(sigfifo[i]));
fifo_depth = 0;
}
return (arg);
}
static void
sighandler (int signo)
{
sigset_t set;
pthread_t self;
if ((signo >= 0) && (signo <= NSIG))
sigcounts[signo]++;
/*
* If we are running on behalf of the suspender thread,
* ensure that we have the correct mask set.
*/
self = pthread_self ();
if (self == suspender_tid) {
sigfifo[fifo_depth] = signo;
fifo_depth++;
printf (" -> Suspender thread signal handler caught "
"signal %d (%s)\n", signo, strsignal(signo));
sigprocmask (SIG_SETMASK, NULL, &set);
ASSERT(set == suspender_mask);
}
else
printf (" -> Main thread signal handler caught "
"signal %d (%s)\n", signo, strsignal(signo));
}
int main (int argc, char *argv[])
{
pthread_attr_t pattr;
struct sigaction act;
sigset_t oldset;
sigset_t newset;
/* Initialize our signal counts. */
memset ((void *) sigcounts, 0, NSIG * sizeof (int));
/* Ignore signal SIGIO. */
sigemptyset (&act.sa_mask);
sigaddset (&act.sa_mask, SIGIO);
act.sa_handler = SIG_IGN;
act.sa_flags = 0;
CHECKe(sigaction (SIGIO, &act, NULL));
/* Install a signal handler for SIGURG. */
sigemptyset (&act.sa_mask);
sigaddset (&act.sa_mask, SIGURG);
act.sa_handler = sighandler;
act.sa_flags = SA_RESTART;
CHECKe(sigaction (SIGURG, &act, NULL));
/* Install a signal handler for SIGXCPU */
sigemptyset (&act.sa_mask);
sigaddset (&act.sa_mask, SIGXCPU);
CHECKe(sigaction (SIGXCPU, &act, NULL));
/* Get our current signal mask. */
CHECKe(sigprocmask (SIG_SETMASK, NULL, &oldset));
/* Mask out SIGUSR1 and SIGUSR2. */
newset = oldset;
sigaddset (&newset, SIGUSR1);
sigaddset (&newset, SIGUSR2);
CHECKe(sigprocmask (SIG_SETMASK, &newset, NULL));
/* Install a signal handler for SIGUSR1 and SIGUSR2 */
sigemptyset (&act.sa_mask);
sigaddset (&act.sa_mask, SIGUSR1);
sigaddset (&act.sa_mask, SIGUSR2);
act.sa_handler = sighandler;
act.sa_flags = SA_RESTART;
CHECKe(sigaction (SIGUSR1, &act, NULL));
CHECKe(sigaction (SIGUSR2, &act, NULL));
/*
* Initialize the thread attribute.
*/
CHECKr(pthread_attr_init (&pattr));
CHECKr(pthread_attr_setdetachstate (&pattr, PTHREAD_CREATE_JOINABLE));
/*
* Create the sigsuspender thread.
*/
CHECKr(pthread_create (&suspender_tid, &pattr, sigsuspender, NULL));
/*
* Verify that an ignored signal doesn't cause a wakeup.
* We don't have a handler installed for SIGIO.
*/
CHECKr(pthread_kill (suspender_tid, SIGIO));
sleep (1);
CHECKe(kill (getpid (), SIGIO));
sleep (1);
/* sigsuspend should not wake up for ignored signal SIGIO */
ASSERT(sigcounts[SIGIO] == 0);
/*
* Verify that a signal with a default action of ignore, for
* which we have a signal handler installed, will release a
* sigsuspend.
*/
CHECKr(pthread_kill (suspender_tid, SIGURG));
sleep (1);
CHECKe(kill (getpid (), SIGURG));
sleep (1);
/* sigsuspend should wake up for SIGURG */
ASSERT(sigcounts[SIGURG] == 3);
/*
* Verify that a SIGUSR2 signal will release a sigsuspended
* thread.
*/
CHECKr(pthread_kill (suspender_tid, SIGUSR2));
sleep (1);
CHECKe(kill (getpid (), SIGUSR2));
sleep (1);
/* sigsuspend should wake yp for SIGUSR2 */
ASSERT(sigcounts[SIGUSR2] == 2);
/*
* Verify that a signal, blocked in both the main and
* sigsuspender threads, does not cause the signal handler
* to be called.
*/
CHECKr(pthread_kill (suspender_tid, SIGUSR1));
sleep (1);
CHECKe(kill (getpid (), SIGUSR1));
sleep (1);
/* signal handler should not be called for USR1 */
ASSERT(sigcounts[SIGUSR1] == 0);
#if 0
/*
* Verify that we can still kill the process for a signal
* not being waited on by sigwait.
*/
CHECKe(kill (getpid (), SIGPIPE));
PANIC("SIGPIPE did not terminate process");
/*
* Wait for the thread to finish.
*/
CHECKr(pthread_join (suspender_tid, NULL));
#endif
SUCCEED;
}
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