/* Common definition for pthread_{timed,try}join{_np}.

   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/>.  */

#include "pthreadP.h"

#include <atomic.h>

#include <stap-probe.h>

static void

cleanup (void *arg)

{

  /* If we already changed the waiter ID, reset it.  The call cannot

     fail for any reason but the thread not having done that yet so

     there is no reason for a loop.  */

  struct pthread *self = THREAD_SELF;

  atomic_compare_exchange_weak_acquire (&arg, &self, NULL);

}

int

__pthread_timedjoin_ex (pthread_t threadid, void **thread_return,

			const struct timespec *abstime, bool block)

{

  struct pthread *pd = (struct pthread *) threadid;

  /* Make sure the descriptor is valid.  */

  if (INVALID_NOT_TERMINATED_TD_P (pd))

    /* Not a valid thread handle.  */

    return ESRCH;

  /* Is the thread joinable?.  */

  if (IS_DETACHED (pd))

    /* We cannot wait for the thread.  */

    return EINVAL;

  struct pthread *self = THREAD_SELF;

  int result = 0;

  LIBC_PROBE (pthread_join, 1, threadid);

  if ((pd == self

       || (self->joinid == pd

	   && (pd->cancelhandling

	       & (CANCELING_BITMASK | CANCELED_BITMASK | EXITING_BITMASK

		  | TERMINATED_BITMASK)) == 0))

      && !CANCEL_ENABLED_AND_CANCELED (self->cancelhandling))

    /* This is a deadlock situation.  The threads are waiting for each

       other to finish.  Note that this is a "may" error.  To be 100%

       sure we catch this error we would have to lock the data

       structures but it is not necessary.  In the unlikely case that

       two threads are really caught in this situation they will

       deadlock.  It is the programmer's problem to figure this

       out.  */

    return EDEADLK;

  /* Wait for the thread to finish.  If it is already locked something

     is wrong.  There can only be one waiter.  */

  else if (__glibc_unlikely (atomic_compare_exchange_weak_acquire (&pd->joinid,

								   &self,

								   NULL)))

    /* There is already somebody waiting for the thread.  */

    return EINVAL;

  if (block)

    {

      /* During the wait we change to asynchronous cancellation.  If we

	 are cancelled the thread we are waiting for must be marked as

	 un-wait-ed for again.  */

      pthread_cleanup_push (cleanup, &pd->joinid);

      int oldtype = CANCEL_ASYNC ();

      if (abstime != NULL)

	result = lll_timedwait_tid (pd->tid, abstime);

      else

	lll_wait_tid (pd->tid);

      CANCEL_RESET (oldtype);

      pthread_cleanup_pop (0);

    }

  if (__glibc_likely (result == 0))

    {

      /* We mark the thread as terminated and as joined.  */

      pd->tid = -1;

      /* Store the return value if the caller is interested.  */

      if (thread_return != NULL)

	*thread_return = pd->result;

      /* Free the TCB.  */

      __free_tcb (pd);

    }

  else

    pd->joinid = NULL;

  LIBC_PROBE (pthread_join_ret, 3, threadid, result, pd->result);

  return result;

}

hidden_def (__pthread_timedjoin_ex)