/* Test for exit/dlclose race (Bug 22180).

   Copyright (C) 2017-2018 Free Software Foundation, Inc.

   This file is part of the GNU C Library.

   The GNU C Library is free software; you can redistribute it and/or

   modify it under the terms of the GNU Lesser General Public

   License as published by the Free Software Foundation; either

   version 2.1 of the License, or (at your option) any later version.

   The GNU C Library is distributed in the hope that it will be useful,

   but WITHOUT ANY WARRANTY; without even the implied warranty of

   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU

   Lesser General Public License for more details.

   You should have received a copy of the GNU Lesser General Public

   License along with the GNU C Library; if not, see

   <http://www.gnu.org/licenses/>.  */

/* This file must be run from within a directory called "stdlib".  */

/* This test verifies that when dlopen in one thread races against exit

   in another thread, we don't call registered destructor twice.

   Expected result:

     second

     first

     ... clean termination

*/

#include <stdio.h>

#include <stdlib.h>

#include <semaphore.h>

#include <support/check.h>

#include <support/xdlfcn.h>

#include <support/xthread.h>

/* Semaphore to ensure we have a happens-before between the first function

   starting and exit being called.  */

sem_t order1;

/* Semaphore to ensure we have a happens-before between the second function

   starting and the first function returning.  */

sem_t order2;

void *

exit_thread (void *arg)

{

  /* Wait for the dlclose to start...  */

  sem_wait (&order1;;

  /* Then try to run the exit sequence which should call all

     __cxa_atexit registered functions and in parallel with

     the executing dlclose().  */

  exit (0);

}

void

last (void)

{

  /* Let dlclose thread proceed.  */

  sem_post (&order2;;

}

int

main (void)

{

  void *dso;

  pthread_t thread;

  atexit (last);

  dso = xdlopen ("$ORIGIN/test-dlclose-exit-race-helper.so",

		 RTLD_NOW|RTLD_GLOBAL);

  thread = xpthread_create (NULL, exit_thread, NULL);

  xdlclose (dso);

  xpthread_join (thread);

  FAIL_EXIT1 ("Did not terminate via exit(0) in exit_thread() as expected.");

}