1  /* Test detachability.
       2     Copyright (C) 2000-2023 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  #define _GNU_SOURCE
      20  
      21  #include <pthread.h>
      22  #include <assert.h>
      23  #include <error.h>
      24  #include <errno.h>
      25  #include <unistd.h>
      26  
      27  void *
      28  thread (void *arg)
      29  {
      30    while (1)
      31      sched_yield ();
      32  }
      33  
      34  int
      35  main (int argc, char **argv)
      36  {
      37    int err;
      38    pthread_t tid;
      39    void *ret;
      40  
      41    err = pthread_create (&tid, 0, thread, 0);
      42    if (err)
      43      error (1, err, "pthread_create");
      44  
      45    err = pthread_detach (tid);
      46    if (err)
      47      error (1, err, "pthread_detach");
      48  
      49    err = pthread_detach (tid);
      50    assert (err == EINVAL);
      51  
      52    err = pthread_join (tid, &ret);
      53    assert (err == EINVAL);
      54  
      55    return 0;
      56  }