glibc/sysdeps/mach/hurd/sigsuspend.c

84 lines
2.6 KiB
C

/* Copyright (C) 1991-2017 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)
strong_alias (__sigsuspend, sigsuspend_not_cancel)
weak_alias (__sigsuspend, sigsuspend)