/* Copyright (C) 1991-2018 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 <errno.h>

#include <hurd.h>

#include <hurd/signal.h>

#include <hurd/msg.h>

/* Change the set of blocked signals to SET,

   wait until a signal arrives, and restore the set of blocked signals.  */

int

__sigsuspend (const sigset_t *set)

{

  struct hurd_sigstate *ss;

  sigset_t newmask, oldmask, pending;

  mach_port_t wait;

  mach_msg_header_t msg;

  if (set != NULL)

    /* Crash before locking.  */

    newmask = *set;

  /* Get a fresh port we will wait on.  */

  wait = __mach_reply_port ();

  ss = _hurd_self_sigstate ();

  __spin_lock (&ss->lock);

  oldmask = ss->blocked;

  if (set != NULL)

    /* Change to the new blocked signal mask.  */

    ss->blocked = newmask & ~_SIG_CANT_MASK;

  /* Notice if any pending signals just became unblocked.  */

  pending = ss->pending & ~ss->blocked;

  /* Tell the signal thread to message us when a signal arrives.  */

  ss->suspended = wait;

  __spin_unlock (&ss->lock);

  if (pending)

    /* Tell the signal thread to check for pending signals.  */

    __msg_sig_post (_hurd_msgport, 0, 0, __mach_task_self ());

  /* Wait for the signal thread's message.  */

  __mach_msg (&msg, MACH_RCV_MSG, 0, sizeof (msg), wait,

	      MACH_MSG_TIMEOUT_NONE, MACH_PORT_NULL);

  __mach_port_destroy (__mach_task_self (), wait);

  __spin_lock (&ss->lock);

  ss->blocked = oldmask;	/* Restore the old mask.  */

  pending = ss->pending & ~ss->blocked;	/* Again check for pending signals.  */

  __spin_unlock (&ss->lock);

  if (pending)

    /* Tell the signal thread to check for pending signals.  */

    __msg_sig_post (_hurd_msgport, 0, 0, __mach_task_self ());

  /* We've been interrupted!  And a good thing, too.

     Otherwise we'd never return.

     That's right; this function always returns an error.  */

  errno = EINTR;

  return -1;

}

libc_hidden_def (__sigsuspend)

weak_alias (__sigsuspend, sigsuspend)