/* Copyright (C) 2002-2018 Free Software Foundation, Inc.

   This file is part of the GNU C Library.

   Contributed by Ulrich Drepper <drepper@redhat.com>, 2002.

   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/>.  */

#include <errno.h>

#include <pthread.h>

#include <stdint.h>

#include <stdio.h>

#include <stdlib.h>

#include <string.h>

#include <unistd.h>

#include <sys/mman.h>

#include <sys/wait.h>

static int

do_test (void)

{

  size_t ps = sysconf (_SC_PAGESIZE);

  char tmpfname[] = "/tmp/tst-rwlock12.XXXXXX";

  char data[ps];

  void *mem;

  int fd;

  pthread_mutex_t *m;

  pthread_mutexattr_t ma;

  pthread_rwlock_t *r;

  pthread_rwlockattr_t ra;

  pid_t pid;

  int status = 0;

  fd = mkstemp (tmpfname);

  if (fd == -1)

    {

      printf ("cannot open temporary file: %m\n");

      return 1;

    }

  /* Make sure it is always removed.  */

  unlink (tmpfname);

  /* Create one page of data.  */

  memset (data, '\0', ps);

  /* Write the data to the file.  */

  if (write (fd, data, ps) != (ssize_t) ps)

    {

      puts ("short write");

      return 1;

    }

  mem = mmap (NULL, ps, PROT_READ | PROT_WRITE, MAP_SHARED, fd, 0);

  if (mem == MAP_FAILED)

    {

      printf ("mmap failed: %m\n");

      return 1;

    }

  r = (pthread_rwlock_t *) (((uintptr_t) mem + __alignof (pthread_rwlock_t))

			    & ~(__alignof (pthread_rwlock_t) - 1));

  /* The following assumes alignment for a mutex is at least as high

     as that for a rwlock.  Which is true in our case.  */

  m = (pthread_mutex_t *) (r + 1);

  if (pthread_rwlockattr_init (&ra) != 0)

    {

      puts ("rwlockattr_init failed");

      return 1;

    }

  if (pthread_rwlockattr_setpshared (&ra, PTHREAD_PROCESS_SHARED) != 0)

    {

      puts ("rwlockattr_setpshared failed");

      return 1;

    }

  if (pthread_rwlock_init (r, &ra) != 0)

    {

      puts ("rwlock_init failed");

      return 1;

    }

  if (pthread_mutexattr_init (&ma) != 0)

    {

      puts ("rwlockattr_init failed");

      return 1;

    }

  if (pthread_mutexattr_setpshared (&ma, PTHREAD_PROCESS_SHARED) != 0)

    {

      puts ("mutexattr_setpshared failed");

      return 1;

    }

  if (pthread_mutex_init (m, &ma) != 0)

    {

      puts ("mutex_init failed");

      return 1;

    }

  /* Lock the mutex.  */

  if (pthread_mutex_lock (m) != 0)

    {

      puts ("mutex_lock failed");

      return 1;

    }

  puts ("going to fork now");

  pid = fork ();

  if (pid == -1)

    {

      puts ("fork failed");

      return 1;

    }

  else if (pid == 0)

    {

      /* Lock the mutex.  */

      if (pthread_mutex_lock (m) != 0)

	{

	  puts ("child: mutex_lock failed");

	  return 1;

	}

      /* Try to get the rwlock.  */

      if (pthread_rwlock_trywrlock (r) == 0)

	{

	  puts ("rwlock_trywrlock succeeded");

	  return 1;

	}

      /* Try again.  */

      struct timespec ts = { .tv_sec = 0, .tv_nsec = 500000000 };

      int e = pthread_rwlock_timedwrlock (r, &ts);

      if (e == 0)

	{

	  puts ("rwlock_timedwrlock succeeded");

	  return 1;

	}

      if (e != ETIMEDOUT)

	{

	  puts ("rwlock_timedwrlock didn't return ETIMEDOUT");

	  status = 1;

	}

      if (pthread_rwlock_tryrdlock (r) == 0)

	{

	  puts ("rwlock_tryrdlock succeeded");

	  return 1;

	}

      e = pthread_rwlock_timedrdlock (r, &ts);

      if (e == 0)

	{

	  puts ("rwlock_timedrdlock succeeded");

	  return 1;

	}

      if (e != ETIMEDOUT)

	{

	  puts ("rwlock_timedrdlock didn't return ETIMEDOUT");

	  status = 1;

	}

    }

  else

    {

      /* Lock the rwlock for writing.  */

      if (pthread_rwlock_wrlock (r) != 0)

	{

	  puts ("rwlock_wrlock failed");

	  kill (pid, SIGTERM);

	  return 1;

	}

      /* Allow the child to run.  */

      if (pthread_mutex_unlock (m) != 0)

	{

	  puts ("mutex_unlock failed");

	  kill (pid, SIGTERM);

	  return 1;

	}

      /* Just wait for the child.  */

      if (TEMP_FAILURE_RETRY (waitpid (pid, &status, 0)) != pid)

	{

	  puts ("waitpid failed");

	  kill (pid, SIGTERM);

	  return 1;

	}

    }

  return status;

}

#define TEST_FUNCTION do_test ()

#include "../test-skeleton.c"