/* Copyright (C) 2006-2018 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/>.  */

/* We define a special synchronization primitive for AIO.  POSIX

   conditional variables would be ideal but the pthread_cond_*wait

   operations do not return on EINTR.  This is a requirement for

   correct aio_suspend and lio_listio implementations.  */

#include <assert.h>

#include <signal.h>

#include <nptl/pthreadP.h>

#include <futex-internal.h>

#define DONT_NEED_GAI_MISC_COND	1

#define GAI_MISC_NOTIFY(waitlist) \

  do {									      \

    if (*waitlist->counterp > 0 && --*waitlist->counterp == 0)		      \

      futex_wake ((unsigned int *) waitlist->counterp, 1, FUTEX_PRIVATE);     \

  } while (0)

#define GAI_MISC_WAIT(result, futex, timeout, cancel) \

  do {									      \

    volatile unsigned int *futexaddr = &futex;				      \

    unsigned int oldval = futex;					      \

									      \

    if (oldval != 0)							      \

      {									      \

	pthread_mutex_unlock (&__gai_requests_mutex);			      \

									      \

	int oldtype;							      \

	if (cancel)							      \

	  oldtype = LIBC_CANCEL_ASYNC ();				      \

									      \

	int status;							      \

	do								      \

	  {								      \

	    status = futex_reltimed_wait ((unsigned int *) futexaddr, oldval, \

					  timeout, FUTEX_PRIVATE);	      \

	    if (status != EAGAIN)					      \

	      break;							      \

									      \

	    oldval = *futexaddr;					      \

	  }								      \

	while (oldval != 0);						      \

									      \

	if (cancel)							      \

	  LIBC_CANCEL_RESET (oldtype);					      \

									      \

	if (status == EINTR)						      \

	  result = EINTR;						      \

	else if (status == ETIMEDOUT)					      \

	  result = EAGAIN;						      \

	else								      \

	  assert (status == 0 || status == EAGAIN);			      \

									      \

	pthread_mutex_lock (&__gai_requests_mutex);			      \

      }									      \

  } while (0)

#define gai_start_notify_thread __gai_start_notify_thread

#define gai_create_helper_thread __gai_create_helper_thread

extern inline void

__gai_start_notify_thread (void)

{

  sigset_t ss;

  sigemptyset (&ss);

  int sigerr __attribute__ ((unused));

  sigerr = pthread_sigmask (SIG_SETMASK, &ss, NULL);

  assert_perror (sigerr);

}

extern inline int

__gai_create_helper_thread (pthread_t *threadp, void *(*tf) (void *),

			    void *arg)

{

  pthread_attr_t attr;

  /* Make sure the thread is created detached.  */

  pthread_attr_init (&attr);

  pthread_attr_setdetachstate (&attr, PTHREAD_CREATE_DETACHED);

  /* The helper thread needs only very little resources.  */

  (void) pthread_attr_setstacksize (&attr,

				    __pthread_get_minstack (&attr)

				    + 4 * PTHREAD_STACK_MIN);

  /* Block all signals in the helper thread.  To do this thoroughly we

     temporarily have to block all signals here.  */

  sigset_t ss;

  sigset_t oss;

  sigfillset (&ss);

  int sigerr __attribute__ ((unused));

  sigerr = pthread_sigmask (SIG_SETMASK, &ss, &oss;;

  assert_perror (sigerr);

  int ret = pthread_create (threadp, &attr, tf, arg);

  /* Restore the signal mask.  */

  sigerr = pthread_sigmask (SIG_SETMASK, &oss, NULL);

  assert_perror (sigerr);

  (void) pthread_attr_destroy (&attr);

  return ret;

}

#include_next <gai_misc.h>