159612Sjasone/* 259612Sjasone * Copyright (c) 1998 Daniel M. Eischen <eischen@vigrid.com> 359612Sjasone * All rights reserved. 459612Sjasone * 559612Sjasone * Redistribution and use in source and binary forms, with or without 659612Sjasone * modification, are permitted provided that the following conditions 759612Sjasone * are met: 859612Sjasone * 1. Redistributions of source code must retain the above copyright 959612Sjasone * notice, this list of conditions and the following disclaimer. 1059612Sjasone * 2. Redistributions in binary form must reproduce the above copyright 1159612Sjasone * notice, this list of conditions and the following disclaimer in the 1259612Sjasone * documentation and/or other materials provided with the distribution. 1359612Sjasone * 3. All advertising materials mentioning features or use of this software 1459612Sjasone * must display the following acknowledgement: 1559612Sjasone * This product includes software developed by Daniel M. Eischen. 1659612Sjasone * 4. Neither the name of the author nor the names of any co-contributors 1759612Sjasone * may be used to endorse or promote products derived from this software 1859612Sjasone * without specific prior written permission. 1959612Sjasone * 2059612Sjasone * THIS SOFTWARE IS PROVIDED BY DANIEL M. EISCHEN AND CONTRIBUTORS ``AS IS'' 2159612Sjasone * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 2259612Sjasone * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 2359612Sjasone * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 2459612Sjasone * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 2559612Sjasone * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 2659612Sjasone * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 2759612Sjasone * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 2859612Sjasone * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 2959612Sjasone * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 3059612Sjasone * SUCH DAMAGE. 3159612Sjasone * 3259612Sjasone * $FreeBSD$ 3359612Sjasone */ 3459612Sjasone#include <stdlib.h> 3559612Sjasone#include <unistd.h> 3659612Sjasone 3759612Sjasone#include <errno.h> 3859612Sjasone#include <pthread.h> 3959612Sjasone#include <signal.h> 4059612Sjasone#include <stdio.h> 4159612Sjasone#include <string.h> 4259612Sjasone 4359612Sjasone#if defined(_LIBC_R_) 4459612Sjasone#include <pthread_np.h> 4559612Sjasone#endif 4659612Sjasone 4759612Sjasonestatic int sigcounts[NSIG + 1]; 4859612Sjasonestatic int sigfifo[NSIG + 1]; 4959612Sjasonestatic int fifo_depth = 0; 5059612Sjasonestatic sigset_t suspender_mask; 5159612Sjasonestatic pthread_t suspender_tid; 5259612Sjasone 5359612Sjasone 5459612Sjasonestatic void * 5559612Sjasonesigsuspender (void *arg) 5659612Sjasone{ 5759612Sjasone int save_count, status, i; 5859612Sjasone sigset_t run_mask; 5959612Sjasone 6059612Sjasone /* Run with all signals blocked. */ 6159612Sjasone sigfillset (&run_mask); 6259612Sjasone sigprocmask (SIG_SETMASK, &run_mask, NULL); 6359612Sjasone 6459612Sjasone /* Allow these signals to wake us up during a sigsuspend. */ 6559612Sjasone sigfillset (&suspender_mask); /* Default action */ 66117706Sdavidxu sigdelset (&suspender_mask, SIGKILL); /* Cannot catch */ 67117706Sdavidxu sigdelset (&suspender_mask, SIGSTOP); /* Cannot catch */ 6859612Sjasone sigdelset (&suspender_mask, SIGINT); /* terminate */ 6959612Sjasone sigdelset (&suspender_mask, SIGHUP); /* terminate */ 7059612Sjasone sigdelset (&suspender_mask, SIGQUIT); /* create core image */ 7159612Sjasone sigdelset (&suspender_mask, SIGURG); /* ignore */ 7259612Sjasone sigdelset (&suspender_mask, SIGIO); /* ignore */ 7359612Sjasone sigdelset (&suspender_mask, SIGUSR2); /* terminate */ 7459612Sjasone 7559612Sjasone while (sigcounts[SIGINT] == 0) { 7659612Sjasone save_count = sigcounts[SIGUSR2]; 7759612Sjasone 7859612Sjasone status = sigsuspend (&suspender_mask); 7959612Sjasone if ((status == 0) || (errno != EINTR)) { 8059612Sjasone fprintf (stderr, "Unable to suspend for signals, " 8159612Sjasone "errno %d, return value %d\n", 8259612Sjasone errno, status); 8359612Sjasone exit (1); 8459612Sjasone } 8559612Sjasone for (i = 0; i < fifo_depth; i++) 8659612Sjasone fprintf (stderr, "Sigsuspend woke up by signal %d\n", 8759612Sjasone sigfifo[i]); 8859612Sjasone fifo_depth = 0; 8959612Sjasone } 9059612Sjasone 9159612Sjasone pthread_exit (arg); 9259612Sjasone return (NULL); 9359612Sjasone} 9459612Sjasone 9559612Sjasone 9659612Sjasonestatic void 9759612Sjasonesighandler (int signo) 9859612Sjasone{ 9959612Sjasone sigset_t set, suspend_set; 10059612Sjasone pthread_t self; 10159612Sjasone 10259612Sjasone if ((signo >= 0) && (signo <= NSIG)) 10359612Sjasone sigcounts[signo]++; 10459612Sjasone 10559612Sjasone /* 10659612Sjasone * If we are running on behalf of the suspender thread, 10759612Sjasone * ensure that we have the correct mask set. 10859612Sjasone */ 10959612Sjasone self = pthread_self (); 11059612Sjasone if (self == suspender_tid) { 11159612Sjasone sigfifo[fifo_depth] = signo; 11259612Sjasone fifo_depth++; 11359612Sjasone fprintf (stderr, 11459612Sjasone " -> Suspender thread signal handler caught signal %d\n", 11559612Sjasone signo); 11659612Sjasone 11759612Sjasone /* Get the current signal mask. */ 11859612Sjasone sigprocmask (SIG_SETMASK, NULL, &set); 11959612Sjasone 12059612Sjasone /* The handler should run with the current signal masked. */ 12159612Sjasone suspend_set = suspender_mask; 12259612Sjasone sigaddset(&suspend_set, signo); 12359612Sjasone 12459612Sjasone if (memcmp(&set, &suspend_set, sizeof(set))) 12559612Sjasone fprintf (stderr, 12659612Sjasone " >>> FAIL: sigsuspender signal handler running " 12759612Sjasone "with incorrect mask.\n"); 12859612Sjasone } 12959612Sjasone else 13059612Sjasone fprintf (stderr, 13159612Sjasone " -> Main thread signal handler caught signal %d\n", 13259612Sjasone signo); 13359612Sjasone} 13459612Sjasone 13559612Sjasone 13659612Sjasonestatic void 13759612Sjasonesend_thread_signal (pthread_t tid, int signo) 13859612Sjasone{ 13959612Sjasone if (pthread_kill (tid, signo) != 0) { 14059612Sjasone fprintf (stderr, "Unable to send thread signal, errno %d.\n", 14159612Sjasone errno); 14259612Sjasone exit (1); 14359612Sjasone } 14459612Sjasone} 14559612Sjasone 14659612Sjasone 14759612Sjasonestatic void 14859612Sjasonesend_process_signal (int signo) 14959612Sjasone{ 15059612Sjasone if (kill (getpid (), signo) != 0) { 15159612Sjasone fprintf (stderr, "Unable to send process signal, errno %d.\n", 15259612Sjasone errno); 15359612Sjasone exit (1); 15459612Sjasone } 15559612Sjasone} 15659612Sjasone 15759612Sjasone 15859612Sjasoneint main (int argc, char *argv[]) 15959612Sjasone{ 16059612Sjasone pthread_attr_t pattr; 16159612Sjasone void * exit_status; 16259612Sjasone struct sigaction act; 16359612Sjasone sigset_t oldset; 16459612Sjasone sigset_t newset; 16559612Sjasone 16659612Sjasone /* Initialize our signal counts. */ 16759612Sjasone memset ((void *) sigcounts, 0, NSIG * sizeof (int)); 16859612Sjasone 16959612Sjasone /* Ignore signal SIGIO. */ 17059612Sjasone sigemptyset (&act.sa_mask); 17159612Sjasone sigaddset (&act.sa_mask, SIGIO); 17259612Sjasone act.sa_handler = SIG_IGN; 17359612Sjasone act.sa_flags = 0; 17459612Sjasone sigaction (SIGIO, &act, NULL); 17559612Sjasone 17659612Sjasone /* Install a signal handler for SIGURG. */ 17759612Sjasone sigemptyset (&act.sa_mask); 17859612Sjasone sigaddset (&act.sa_mask, SIGURG); 17959612Sjasone act.sa_handler = sighandler; 18059612Sjasone act.sa_flags = SA_RESTART; 18159612Sjasone sigaction (SIGURG, &act, NULL); 18259612Sjasone 18359612Sjasone /* Install a signal handler for SIGXCPU */ 18459612Sjasone sigemptyset (&act.sa_mask); 18559612Sjasone sigaddset (&act.sa_mask, SIGXCPU); 18659612Sjasone sigaction (SIGXCPU, &act, NULL); 18759612Sjasone 18859612Sjasone /* Get our current signal mask. */ 18959612Sjasone sigprocmask (SIG_SETMASK, NULL, &oldset); 19059612Sjasone 19159612Sjasone /* Mask out SIGUSR1 and SIGUSR2. */ 19259612Sjasone newset = oldset; 19359612Sjasone sigaddset (&newset, SIGUSR1); 19459612Sjasone sigaddset (&newset, SIGUSR2); 19559612Sjasone sigprocmask (SIG_SETMASK, &newset, NULL); 19659612Sjasone 19759612Sjasone /* Install a signal handler for SIGUSR1 */ 19859612Sjasone sigemptyset (&act.sa_mask); 19959612Sjasone sigaddset (&act.sa_mask, SIGUSR1); 20059612Sjasone sigaction (SIGUSR1, &act, NULL); 20159612Sjasone 20259612Sjasone /* Install a signal handler for SIGUSR2 */ 20359612Sjasone sigemptyset (&act.sa_mask); 20459612Sjasone sigaddset (&act.sa_mask, SIGUSR2); 20559612Sjasone sigaction (SIGUSR2, &act, NULL); 20659612Sjasone 20759612Sjasone /* 20859612Sjasone * Initialize the thread attribute. 20959612Sjasone */ 21059612Sjasone if ((pthread_attr_init (&pattr) != 0) || 21159612Sjasone (pthread_attr_setdetachstate (&pattr, 21259612Sjasone PTHREAD_CREATE_JOINABLE) != 0)) { 21359612Sjasone fprintf (stderr, "Unable to initialize thread attributes.\n"); 21459612Sjasone exit (1); 21559612Sjasone } 21659612Sjasone 21759612Sjasone /* 21859612Sjasone * Create the sigsuspender thread. 21959612Sjasone */ 22059612Sjasone if (pthread_create (&suspender_tid, &pattr, sigsuspender, NULL) != 0) { 22159612Sjasone fprintf (stderr, "Unable to create thread, errno %d.\n", errno); 22259612Sjasone exit (1); 22359612Sjasone } 224152597Smarcel#if defined(_LIBC_R_) 22559612Sjasone pthread_set_name_np (suspender_tid, "sigsuspender"); 22659612Sjasone#endif 22759612Sjasone 22859612Sjasone /* 22959612Sjasone * Verify that an ignored signal doesn't cause a wakeup. 23059612Sjasone * We don't have a handler installed for SIGIO. 23159612Sjasone */ 23259612Sjasone send_thread_signal (suspender_tid, SIGIO); 23359612Sjasone sleep (1); 23459612Sjasone send_process_signal (SIGIO); 23559612Sjasone sleep (1); 23659612Sjasone if (sigcounts[SIGIO] != 0) 23759612Sjasone fprintf (stderr, "FAIL: sigsuspend wakes up for ignored signal " 23859612Sjasone "SIGIO.\n"); 23959612Sjasone 24059612Sjasone /* 24159612Sjasone * Verify that a signal with a default action of ignore, for 24259612Sjasone * which we have a signal handler installed, will release a 24359612Sjasone * sigsuspend. 24459612Sjasone */ 24559612Sjasone send_thread_signal (suspender_tid, SIGURG); 24659612Sjasone sleep (1); 24759612Sjasone send_process_signal (SIGURG); 24859612Sjasone sleep (1); 24959612Sjasone if (sigcounts[SIGURG] != 2) 25059612Sjasone fprintf (stderr, 25159612Sjasone "FAIL: sigsuspend doesn't wake up for SIGURG.\n"); 25259612Sjasone 25359612Sjasone /* 25459612Sjasone * Verify that a SIGUSR2 signal will release a sigsuspended 25559612Sjasone * thread. 25659612Sjasone */ 25759612Sjasone send_thread_signal (suspender_tid, SIGUSR2); 25859612Sjasone sleep (1); 25959612Sjasone send_process_signal (SIGUSR2); 26059612Sjasone sleep (1); 26159612Sjasone if (sigcounts[SIGUSR2] != 2) 26259612Sjasone fprintf (stderr, 26359612Sjasone "FAIL: sigsuspend doesn't wake up for SIGUSR2.\n"); 26459612Sjasone 26559612Sjasone /* 26659612Sjasone * Verify that a signal, blocked in both the main and 26759612Sjasone * sigsuspender threads, does not cause the signal handler 26859612Sjasone * to be called. 26959612Sjasone */ 27059612Sjasone send_thread_signal (suspender_tid, SIGUSR1); 27159612Sjasone sleep (1); 27259612Sjasone send_process_signal (SIGUSR1); 27359612Sjasone sleep (1); 27459612Sjasone if (sigcounts[SIGUSR1] != 0) 27559612Sjasone fprintf (stderr, "FAIL: signal hander called for SIGUSR1.\n"); 27659612Sjasone 27759612Sjasone /* 27859612Sjasone * Verify that we can still kill the process for a signal 27959612Sjasone * not being waited on by sigwait. 28059612Sjasone */ 28159612Sjasone send_process_signal (SIGPIPE); 28259612Sjasone fprintf (stderr, "FAIL: SIGPIPE did not terminate process.\n"); 28359612Sjasone 28459612Sjasone /* 28559612Sjasone * Wait for the thread to finish. 28659612Sjasone */ 28759612Sjasone pthread_join (suspender_tid, &exit_status); 28859612Sjasone 28959612Sjasone return (0); 29059612Sjasone} 291