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/* $OpenBSD: sigwait.c,v 1.2 2001/11/11 23:26:35 deraadt 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 sigset_t wait_mask;
static pthread_mutex_t waiter_mutex;
static void *
sigwaiter (void *arg)
{
int signo;
sigset_t mask;
SET_NAME("sigwaiter");
/* Block SIGHUP */
sigemptyset (&mask);
sigaddset (&mask, SIGHUP);
CHECKe(sigprocmask (SIG_BLOCK, &mask, NULL));
while (sigcounts[SIGINT] == 0) {
printf("Sigwait waiting (thread %p)\n", pthread_self());
CHECKe(sigwait (&wait_mask, &signo));
sigcounts[signo]++;
printf ("Sigwait caught signal %d (%s)\n", signo,
strsignal(signo));
/* Allow the main thread to prevent the sigwait. */
CHECKr(pthread_mutex_lock (&waiter_mutex));
CHECKr(pthread_mutex_unlock (&waiter_mutex));
}
return (arg);
}
static void
sighandler (int signo)
{
int save_errno = errno;
char buf[8192];
snprintf(buf, sizeof buf,
" -> Signal handler caught signal %d (%s) in thread %p\n",
signo, strsignal(signo), pthread_self());
write(STDOUT_FILENO, buf, strlen(buf));
if ((signo >= 0) && (signo <= NSIG))
sigcounts[signo]++;
errno = save_errno;
}
int main (int argc, char *argv[])
{
pthread_mutexattr_t mattr;
pthread_attr_t pattr;
pthread_t tid;
struct sigaction act;
/* Initialize our signal counts. */
memset ((void *) sigcounts, 0, NSIG * sizeof (int));
/* Setupt our wait mask. */
sigemptyset (&wait_mask); /* Default action */
sigaddset (&wait_mask, SIGHUP); /* terminate */
sigaddset (&wait_mask, SIGINT); /* terminate */
sigaddset (&wait_mask, SIGQUIT); /* create core image */
sigaddset (&wait_mask, SIGURG); /* ignore */
sigaddset (&wait_mask, SIGIO); /* ignore */
sigaddset (&wait_mask, SIGUSR1); /* terminate */
/* Ignore signals SIGHUP and SIGIO. */
sigemptyset (&act.sa_mask);
sigaddset (&act.sa_mask, SIGHUP);
sigaddset (&act.sa_mask, SIGIO);
act.sa_handler = SIG_IGN;
act.sa_flags = 0;
CHECKe(sigaction (SIGHUP, &act, NULL));
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));
/*
* Initialize the thread attribute.
*/
CHECKr(pthread_attr_init (&pattr));
CHECKr(pthread_attr_setdetachstate (&pattr, PTHREAD_CREATE_JOINABLE));
/*
* Initialize and create a mutex.
*/
CHECKr(pthread_mutexattr_init (&mattr));
CHECKr(pthread_mutex_init (&waiter_mutex, &mattr));
/*
* Create the sigwaiter thread.
*/
CHECKr(pthread_create (&tid, &pattr, sigwaiter, NULL));
/*
* Verify that an ignored signal doesn't cause a wakeup.
* We don't have a handler installed for SIGIO.
*/
CHECKr(pthread_kill (tid, SIGIO));
sleep (1);
CHECKe(kill(getpid(), SIGIO));
sleep (1);
/* sigwait 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 sigwait.
*/
CHECKr(pthread_kill (tid, SIGURG));
sleep (1);
CHECKe(kill(getpid(), SIGURG));
sleep (1);
/* sigwait should wake up for SIGURG */
ASSERT(sigcounts[SIGURG] == 2);
/*
* Verify that a signal with a default action that terminates
* the process will release a sigwait.
*/
CHECKr(pthread_kill (tid, SIGUSR1));
sleep (1);
CHECKe(kill(getpid(), SIGUSR1));
sleep (1);
if (sigcounts[SIGUSR1] != 2)
printf ("FAIL: sigwait doesn't wake up for SIGUSR1.\n");
/*
* Verify that if we install a signal handler for a previously
* ignored signal, an occurrence of this signal will release
* the (already waiting) sigwait.
*/
/* Install a signal handler for SIGHUP. */
sigemptyset (&act.sa_mask);
sigaddset (&act.sa_mask, SIGHUP);
act.sa_handler = sighandler;
act.sa_flags = SA_RESTART;
CHECKe(sigaction (SIGHUP, &act, NULL));
/* Sending SIGHUP should release the sigwait. */
CHECKe(kill(getpid(), SIGHUP));
sleep (1);
CHECKr(pthread_kill (tid, SIGHUP));
sleep (1);
/* sigwait should wake up for SIGHUP */
ASSERT(sigcounts[SIGHUP] == 2);
/*
* Verify that a pending signal in the waiters mask will
* cause sigwait to return the pending signal. We do this
* by taking the waiters mutex and signaling the waiter to
* release him from the sigwait. The waiter will block
* on taking the mutex, and we can then send the waiter a
* signal which should be added to his pending signals.
* The next time the waiter does a sigwait, he should
* return with the pending signal.
*/
sigcounts[SIGHUP] = 0;
CHECKr(pthread_mutex_lock (&waiter_mutex));
/* Release the waiter from sigwait. */
CHECKe(kill(getpid(), SIGHUP));
sleep (1);
/* sigwait should wake up for SIGHUP */
ASSERT(sigcounts[SIGHUP] == 1);
/*
* Add SIGHUP to all threads pending signals. Since there is
* a signal handler installed for SIGHUP and this signal is
* blocked from the waiter thread and unblocked in the main
* thread, the signal handler should be called once for SIGHUP.
*/
CHECKe(kill(getpid(), SIGHUP));
/* Release the waiter thread and allow him to run. */
CHECKr(pthread_mutex_unlock (&waiter_mutex));
sleep (1);
/* sigwait should return for pending SIGHUP */
ASSERT(sigcounts[SIGHUP] == 3);
/*
* Repeat the above test using pthread_kill and SIGUSR1
*/
sigcounts[SIGUSR1] = 0;
CHECKr(pthread_mutex_lock (&waiter_mutex));
/* Release the waiter from sigwait. */
CHECKr(pthread_kill (tid, SIGUSR1));
sleep (1);
/* sigwait should wake up for SIGUSR1 */
ASSERT(sigcounts[SIGUSR1] == 1);
/* Add SIGHUP to the waiters pending signals. */
CHECKr(pthread_kill (tid, SIGUSR1));
/* Release the waiter thread and allow him to run. */
CHECKe(pthread_mutex_unlock (&waiter_mutex));
sleep (1);
/* sigwait should return for pending SIGUSR1 */
ASSERT(sigcounts[SIGUSR1] == 2);
#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 (tid, NULL));
#endif
SUCCEED;
}
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