Attachment 275431 Details for Bug 408321 – Test program for pthread_cond_timedwait usage when signal arrives

Test program for pthread_cond_timedwait usage when signal arrives

pthread_cond_timedwait_test.c (text/plain), 4.42 KB, created by David Holmes on 2007-12-03 06:20:32 UTC

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Creator: David Holmes

Created: 2007-12-03 06:20:32 UTC

Size: 4.42 KB

patch

obsolete

>#include <stdio.h>
>#include <unistd.h>
>#include <pthread.h>
>#include <time.h>
>#include <errno.h>
>#include <string.h>
>#include <signal.h>
>
>/* This is a simple test to see if a pthread_cond_timedwait is
>   incorrectly terminated when process control signals, and others, are
>   sent to the process ie SIGTSTP and SIGCONT. We have observed
>   cases where the wait returns with ETIMEDOUT.
>   We install a signal handler for SIGUSR1 and SIGRTMIN
>*/
>
>static void my_handler(int sig, siginfo_t *sip, void *uvp) {
>  printf("Received signal %d\n", sig);
>}
>
>int main (int argc, char* argv[]) {
>
>  int status;
>
>  clock_t clock = (argc > 1) ? CLOCK_REALTIME : CLOCK_MONOTONIC;
>  char* clock_name = (argc > 1) ? "CLOCK_REALTIME" : "CLOCK_MONOTONIC";
>
>  // first initialize the pthread_cond_t to use the desired clock
>
>  pthread_condattr_t attr;
>  pthread_cond_t cv;
>
>  if ((status = pthread_condattr_init(&attr)) != 0) {
>    printf("pthread_condattr_init: %s", strerror(status));
>    return -1;
>  }
>
>  if ((status = pthread_condattr_setclock(&attr, clock)) != 0) {
>    if (status == EINVAL)
>      printf("Clock %s requested for pthread_cond_t is not supported\n", clock_name);
>    else {
>      printf("pthread_condattr_setclock: %s\n", strerror(status));
>      return -1;
>    }
>  }
>  
>  
>  if ((status = pthread_cond_init(&cv, &attr)) != 0) {
>    printf("pthread_cond_init: %s\n", strerror(status));
>    return -1;
>    
>  }
>  if ((status = pthread_condattr_destroy(&attr)) != 0) {
>    printf("pthread_condattr_destroy: %s\n", strerror(status));
>    return -1;
>  }
>  
>  // now initialize the mutex 
>
>  pthread_mutex_t mutex;
>
>  pthread_mutexattr_t mattr;
>  if ((status = pthread_mutexattr_init(&mattr)) != 0) {
>    printf("pthread_mutexattr_init: %s\n", strerror(status));
>    return -1;
>  }
>#if 0  
>  if ((status = pthread_mutexattr_setprotocol(&mattr, PTHREAD_PRIO_INHERIT)) != 0) {
>    if (status == ENOTSUP)
>      printf("Priority-inheritance is not supported for mutexes\n");
>    else {
>      printf("pthread_mutexattr_setprotocol: %s\n", strerror(status));
>      return -1;
>    }
>  }
>#endif  
>  if ((status = pthread_mutex_init(&mutex, &mattr)) != 0) {
>    printf("pthread_mutex_init: %s\n", strerror(status));
>    return -1;
>  }
>  if ((status = pthread_mutexattr_destroy(&mattr)) != 0) {
>    printf("pthread_mutexattr_destroy: %s\n", strerror(status));
>    return -1;
>  }
>
>  // install signal handler for the RT signal and SIGUSR1
>
>  sigset_t mask_sigs;
>  struct sigaction sigact;
>
>  sigfillset(&mask_sigs);
>  sigact.sa_sigaction = my_handler;
>  sigact.sa_mask = mask_sigs;
>  sigact.sa_flags = SA_SIGINFO;
>
>  if(sigaction(SIGUSR1,&sigact,NULL) == -1) {
>    printf("sigaction() failed for SIGUSR1: %s", strerror(errno));
>    return -1;
>  }
>
>  if(sigaction(SIGRTMIN,&sigact,NULL) == -1) {
>    printf("sigaction() failed for SIGRTMIN: %s", strerror(errno));
>    return -1;
>  }
>
>  sigemptyset(&mask_sigs);
>  sigaddset(&mask_sigs,SIGUSR1);
>  sigaddset(&mask_sigs,SIGRTMIN);
>  if ((status = pthread_sigmask(SIG_UNBLOCK,&mask_sigs,NULL)) != 0) {
>    printf("pthread_sigmask: %s\n", strerror(status));
>    return -1;
>  }
>
>
>  // now do the wait;
>
>  status = pthread_mutex_lock(&mutex);
>  if (status != 0) {
>    printf("pthread_mutex_lock: %s\n", strerror(status));
>    return -1;
>  }
>
>  int timeout = 60;
>  struct timespec start;
>  struct timespec end;
>  struct timespec expected;
>  clock_gettime(clock, &start);
>  expected.tv_sec = start.tv_sec + timeout;
>  expected.tv_nsec = start.tv_nsec;
>
>  volatile int done = 0;
>
>  while (!done) {
>    
>    printf("Thread about to do %d sec pthread_cond_timedwait - send signals\n", timeout);
>
>    status = pthread_cond_timedwait(&cv, &mutex, &expected);
>    clock_gettime(clock, &end);
>
>    if (status == EINTR) {
>      printf("Broken linux: pthread_cond_wait returned EINTR\n");
>      return -1 ; 
>    }
>    if (status == ETIMEDOUT) {
>      int elapsed = end.tv_sec - start.tv_sec;
>      int n_elapsed = end.tv_nsec - start.tv_nsec;
>      if (n_elapsed < 0)
>	n_elapsed += 1000000000;
>      if (elapsed < timeout) {
>	printf("Error: pthread_cond_wait returned early: %d secs, %d nsecs\n",
>	       elapsed, n_elapsed );
>	return -1 ; 
>      }
>      else {
>	printf("Returned ok\n");
>	return 0;
>      }
>    }
>    if (status == ETIME) {
>      printf("Broken linux: pthread_cond_wait returned ETIME\n");
>      return -1 ; 
>    }
>    if (status != 0) {
>      printf("pthread_cond_timedwait: %s\n", strerror(status));
>      return -1;
>    }
>    else {
>      printf("spurious wakeup ?\n");
>    }
>  }
>
>  return 0;
>}

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Attachments on bug 408321: 275431 | 278331