274 lines
7.4 KiB
C
274 lines
7.4 KiB
C
/*
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* Copyright (c) 1998 Daniel M. Eischen <eischen@vigrid.com>
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* All rights reserved.
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*
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that the following conditions
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* are met:
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* 1. Redistributions of source code must retain the above copyright
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* notice, this list of conditions and the following disclaimer.
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* 2. Redistributions in binary form must reproduce the above copyright
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* notice, this list of conditions and the following disclaimer in the
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* documentation and/or other materials provided with the distribution.
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* 3. All advertising materials mentioning features or use of this software
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* must display the following acknowledgement:
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* This product includes software developed by Daniel M. Eischen.
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* 4. Neither the name of the author nor the names of any co-contributors
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* may be used to endorse or promote products derived from this software
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* without specific prior written permission.
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*
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* THIS SOFTWARE IS PROVIDED BY DANIEL M. EISCHEN AND CONTRIBUTORS ``AS IS''
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* AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
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* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
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* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
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* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
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* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
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* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
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* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
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* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
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* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
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* SUCH DAMAGE.
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*
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*/
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#include <stdlib.h>
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#include <unistd.h>
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#include <errno.h>
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#include <pthread.h>
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#include <signal.h>
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#include <stdio.h>
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#include <string.h>
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#if defined(__FreeBSD__)
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#include <pthread_np.h>
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#endif
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static int sigcounts[NSIG + 1];
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static int sigfifo[NSIG + 1];
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static int fifo_depth = 0;
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static sigset_t suspender_mask;
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static pthread_t suspender_tid;
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static void *
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sigsuspender (void *arg)
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{
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int save_count, status, i;
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sigset_t run_mask;
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/* Run with all signals blocked. */
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sigfillset (&run_mask);
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sigprocmask (SIG_SETMASK, &run_mask, NULL);
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/* Allow these signals to wake us up during a sigsuspend. */
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sigfillset (&suspender_mask); /* Default action */
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sigdelset (&suspender_mask, SIGINT); /* terminate */
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sigdelset (&suspender_mask, SIGHUP); /* terminate */
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sigdelset (&suspender_mask, SIGQUIT); /* create core image */
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sigdelset (&suspender_mask, SIGURG); /* ignore */
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sigdelset (&suspender_mask, SIGIO); /* ignore */
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sigdelset (&suspender_mask, SIGUSR2); /* terminate */
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while (sigcounts[SIGINT] == 0) {
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save_count = sigcounts[SIGUSR2];
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status = sigsuspend (&suspender_mask);
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if ((status == 0) || (errno != EINTR)) {
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printf ("Unable to suspend for signals, "
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"errno %d, return value %d\n",
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errno, status);
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exit (1);
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}
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for (i = 0; i < fifo_depth; i++)
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printf ("Sigsuspend woke up by signal %d\n",
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sigfifo[i]);
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fifo_depth = 0;
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}
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pthread_exit (arg);
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return (NULL);
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}
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static void
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sighandler (int signo)
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{
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sigset_t set;
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pthread_t self;
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if ((signo >= 0) && (signo <= NSIG))
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sigcounts[signo]++;
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/*
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* If we are running on behalf of the suspender thread,
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* ensure that we have the correct mask set.
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*/
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self = pthread_self ();
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if (self == suspender_tid) {
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sigfifo[fifo_depth] = signo;
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fifo_depth++;
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printf (" -> Suspender thread signal handler caught signal %d\n",
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signo);
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sigprocmask (SIG_SETMASK, NULL, &set);
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if (set != suspender_mask)
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printf (" >>> FAIL: sigsuspender signal handler running "
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"with incorrect mask.\n");
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}
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else
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printf (" -> Main thread signal handler caught signal %d\n",
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signo);
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}
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static void
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send_thread_signal (pthread_t tid, int signo)
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{
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if (pthread_kill (tid, signo) != 0) {
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printf ("Unable to send thread signal, errno %d.\n", errno);
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exit (1);
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}
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}
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static void
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send_process_signal (int signo)
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{
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if (kill (getpid (), signo) != 0) {
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printf ("Unable to send process signal, errno %d.\n", errno);
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exit (1);
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}
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}
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int main (int argc, char *argv[])
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{
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pthread_attr_t pattr;
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void * exit_status;
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struct sigaction act;
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sigset_t oldset;
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sigset_t newset;
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/* Initialize our signal counts. */
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memset ((void *) sigcounts, 0, NSIG * sizeof (int));
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/* Ignore signal SIGIO. */
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sigemptyset (&act.sa_mask);
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sigaddset (&act.sa_mask, SIGIO);
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act.sa_handler = SIG_IGN;
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act.sa_flags = 0;
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sigaction (SIGIO, &act, NULL);
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/* Install a signal handler for SIGURG. */
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sigemptyset (&act.sa_mask);
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sigaddset (&act.sa_mask, SIGURG);
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act.sa_handler = sighandler;
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act.sa_flags = SA_RESTART;
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sigaction (SIGURG, &act, NULL);
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/* Install a signal handler for SIGXCPU */
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sigemptyset (&act.sa_mask);
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sigaddset (&act.sa_mask, SIGXCPU);
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sigaction (SIGXCPU, &act, NULL);
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/* Get our current signal mask. */
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sigprocmask (SIG_SETMASK, NULL, &oldset);
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/* Mask out SIGUSR1 and SIGUSR2. */
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newset = oldset;
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sigaddset (&newset, SIGUSR1);
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sigaddset (&newset, SIGUSR2);
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sigprocmask (SIG_SETMASK, &newset, NULL);
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/* Install a signal handler for SIGUSR1 and SIGUSR2 */
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sigemptyset (&act.sa_mask);
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sigaddset (&act.sa_mask, SIGUSR1);
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sigaddset (&act.sa_mask, SIGUSR2);
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act.sa_handler = sighandler;
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act.sa_flags = SA_RESTART;
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sigaction (SIGUSR1, &act, NULL);
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sigaction (SIGUSR2, &act, NULL);
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/*
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* Initialize the thread attribute.
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*/
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if ((pthread_attr_init (&pattr) != 0) ||
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(pthread_attr_setdetachstate (&pattr,
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PTHREAD_CREATE_JOINABLE) != 0)) {
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printf ("Unable to initialize thread attributes.\n");
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exit (1);
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}
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/*
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* Create the sigsuspender thread.
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*/
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if (pthread_create (&suspender_tid, &pattr, sigsuspender, NULL) != 0) {
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printf ("Unable to create thread, errno %d.\n", errno);
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exit (1);
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}
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#if defined(__FreeBSD__)
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pthread_set_name_np (suspender_tid, "sigsuspender");
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#endif
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/*
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* Verify that an ignored signal doesn't cause a wakeup.
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* We don't have a handler installed for SIGIO.
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*/
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send_thread_signal (suspender_tid, SIGIO);
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sleep (1);
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send_process_signal (SIGIO);
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sleep (1);
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if (sigcounts[SIGIO] != 0)
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printf ("FAIL: sigsuspend wakes up for ignored signal "
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"SIGIO.\n");
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/*
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* Verify that a signal with a default action of ignore, for
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* which we have a signal handler installed, will release a
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* sigsuspend.
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*/
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send_thread_signal (suspender_tid, SIGURG);
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sleep (1);
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send_process_signal (SIGURG);
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sleep (1);
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if (sigcounts[SIGURG] != 3)
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printf ("FAIL: sigsuspend doesn't wake up for SIGURG.\n");
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/*
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* Verify that a SIGUSR2 signal will release a sigsuspended
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* thread.
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*/
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send_thread_signal (suspender_tid, SIGUSR2);
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sleep (1);
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send_process_signal (SIGUSR2);
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sleep (1);
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if (sigcounts[SIGUSR2] != 2)
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printf ("FAIL: sigsuspend doesn't wake up for SIGUSR2.\n");
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/*
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* Verify that a signal, blocked in both the main and
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* sigsuspender threads, does not cause the signal handler
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* to be called.
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*/
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send_thread_signal (suspender_tid, SIGUSR1);
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sleep (1);
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send_process_signal (SIGUSR1);
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sleep (1);
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if (sigcounts[SIGUSR1] != 0)
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printf ("FAIL: signal hander called for SIGUSR1.\n");
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/*
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* Verify that we can still kill the process for a signal
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* not being waited on by sigwait.
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*/
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send_process_signal (SIGPIPE);
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printf ("FAIL: SIGPIPE did not terminate process.\n");
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/*
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* Wait for the thread to finish.
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*/
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pthread_join (suspender_tid, &exit_status);
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return (0);
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}
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