/* Cancel a thread.

   Copyright (C) 2002-2018 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 <pthread.h>

#include <pt-internal.h>

int

pthread_cancel (pthread_t t)

{

  int err = 0;

  struct __pthread *p;

  p = __pthread_getid (t);

  if (p == NULL)

    return ESRCH;

  __pthread_mutex_lock (&p->cancel_lock);

  if (p->cancel_pending)

    {

      __pthread_mutex_unlock (&p->cancel_lock);

      return 0;

    }

  p->cancel_pending = 1;

  if (p->cancel_state != PTHREAD_CANCEL_ENABLE)

    {

      __pthread_mutex_unlock (&p->cancel_lock);

      return 0;

    }

  if (p->cancel_type == PTHREAD_CANCEL_ASYNCHRONOUS)

    /* CANCEL_LOCK is unlocked by this call.  */

    err = __pthread_do_cancel (p);

  else

    {

      if (p->cancel_hook != NULL)

	/* Thread blocking on a cancellation point.  Invoke hook to unblock.

	   See __pthread_cond_timedwait_internal.  */

	p->cancel_hook (p->cancel_hook_arg);

      __pthread_mutex_unlock (&p->cancel_lock);

    }

  return err;

}