1  /* Test sem_wait cancellation for contended case.
       2     Copyright (C) 2003-2023 Free Software Foundation, Inc.
       3     This file is part of the GNU C Library.
       4  
       5     The GNU C Library is free software; you can redistribute it and/or
       6     modify it under the terms of the GNU Lesser General Public
       7     License as published by the Free Software Foundation; either
       8     version 2.1 of the License, or (at your option) any later version.
       9  
      10     The GNU C Library is distributed in the hope that it will be useful,
      11     but WITHOUT ANY WARRANTY; without even the implied warranty of
      12     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
      13     Lesser General Public License for more details.
      14  
      15     You should have received a copy of the GNU Lesser General Public
      16     License along with the GNU C Library; if not, see
      17     <https://www.gnu.org/licenses/>.  */
      18  
      19  #include <errno.h>
      20  #include <pthread.h>
      21  #include <semaphore.h>
      22  #include <stdio.h>
      23  #include <stdlib.h>
      24  #include <string.h>
      25  #include <unistd.h>
      26  
      27  
      28  static pthread_barrier_t bar;
      29  static sem_t sem;
      30  
      31  
      32  static void
      33  cleanup (void *arg)
      34  {
      35    static int ncall;
      36  
      37    if (++ncall != 1)
      38      {
      39        puts ("second call to cleanup");
      40        exit (1);
      41      }
      42  }
      43  
      44  
      45  static void *
      46  tf (void *arg)
      47  {
      48    pthread_cleanup_push (cleanup, NULL);
      49  
      50    int e = pthread_barrier_wait (&bar);
      51    if (e != 0 && e != PTHREAD_BARRIER_SERIAL_THREAD)
      52      {
      53        puts ("error: tf: 1st barrier_wait failed");
      54        exit (1);
      55      }
      56  
      57    /* This call should block and be cancelable.  */
      58    sem_wait (&sem);
      59  
      60    pthread_cleanup_pop (0);
      61  
      62    return NULL;
      63  }
      64  
      65  
      66  static int
      67  do_test (void)
      68  {
      69    pthread_t th;
      70  
      71    if (pthread_barrier_init (&bar, NULL, 2) != 0)
      72      {
      73        puts ("error: barrier_init failed");
      74        exit (1);
      75      }
      76  
      77    /* A value equal to 0 will check for contended pthread cancellation,
      78       where the sem_wait operation will block.  */
      79    if (sem_init (&sem, 0, 0) != 0)
      80      {
      81        puts ("error: sem_init failed");
      82        exit (1);
      83      }
      84  
      85    if (pthread_create (&th, NULL, tf, NULL) != 0)
      86      {
      87        puts ("error: create failed");
      88        exit (1);
      89      }
      90  
      91    int e = pthread_barrier_wait (&bar);
      92    if (e != 0 && e != PTHREAD_BARRIER_SERIAL_THREAD)
      93      {
      94        puts ("error: 1st barrier_wait failed");
      95        exit (1);
      96      }
      97  
      98    /* Give the child a chance to go to sleep in sem_wait.  */
      99    sleep (1);
     100  
     101    /* Check whether cancellation is honored when waiting in sem_wait.  */
     102    if (pthread_cancel (th) != 0)
     103      {
     104        puts ("error: 1st cancel failed");
     105        exit (1);
     106      }
     107  
     108    void *r;
     109    if (pthread_join (th, &r) != 0)
     110      {
     111        puts ("error: join failed");
     112        exit (1);
     113      }
     114  
     115    if (r != PTHREAD_CANCELED)
     116      {
     117        puts ("thread not canceled");
     118        exit (1);
     119      }
     120  
     121    return 0;
     122  }
     123  
     124  
     125  #define TEST_FUNCTION do_test ()
     126  #include "../test-skeleton.c"