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/* Copyright (C) 1996-2020 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
<https://www.gnu.org/licenses/>. */
#include <errno.h>
#include <hurd.h>
#include <hurd/signal.h>
#include <hurd/msg.h>
#include <hurd/sigpreempt.h>
#include <assert.h>
#include <sysdep-cancel.h>
/* Select any of pending signals from SET or wait for any to arrive. */
int
__sigwait (const sigset_t *set, int *sig)
{
struct hurd_sigstate *ss;
sigset_t mask, ready, blocked;
int signo = 0;
struct hurd_signal_preemptor preemptor;
jmp_buf buf;
mach_port_t wait;
mach_msg_header_t msg;
int cancel_oldtype;
sighandler_t
preempt_fun (struct hurd_signal_preemptor *pe,
struct hurd_sigstate *ss,
int *sigp,
struct hurd_signal_detail *detail)
{
if (signo)
/* We've already been run; don't interfere. */
return SIG_ERR;
signo = *sigp;
/* Make sure this is all kosher */
assert (__sigismember (&mask, signo));
/* Restore the blocking mask. */
ss->blocked = blocked;
return pe->handler;
}
void
handler (int sig)
{
assert (sig == signo);
longjmp (buf, 1);
}
wait = __mach_reply_port ();
if (set != NULL)
/* Crash before locking */
mask = *set;
else
__sigemptyset (&mask);
ss = _hurd_self_sigstate ();
cancel_oldtype = LIBC_CANCEL_ASYNC();
_hurd_sigstate_lock (ss);
/* See if one of these signals is currently pending. */
sigset_t pending = _hurd_sigstate_pending (ss);
__sigandset (&ready, &pending, &mask);
if (! __sigisemptyset (&ready))
{
for (signo = 1; signo < NSIG; signo++)
if (__sigismember (&ready, signo))
{
__sigdelset (&ready, signo);
goto all_done;
}
/* Huh? Where'd it go? */
abort ();
}
/* Wait for one of them to show up. */
if (!setjmp (buf))
{
/* Make the preemptor */
preemptor.signals = mask;
preemptor.first = 0;
preemptor.last = -1;
preemptor.preemptor = preempt_fun;
preemptor.handler = handler;
/* Install this preemptor */
preemptor.next = ss->preemptors;
ss->preemptors = &preemptor;
/* Unblock the expected signals */
blocked = ss->blocked;
ss->blocked &= ~mask;
_hurd_sigstate_unlock (ss);
/* Wait. */
__mach_msg (&msg, MACH_RCV_MSG, 0, sizeof (msg), wait,
MACH_MSG_TIMEOUT_NONE, MACH_PORT_NULL);
abort ();
}
else
{
assert (signo);
_hurd_sigstate_lock (ss);
/* Delete our preemptor. */
assert (ss->preemptors == &preemptor);
ss->preemptors = preemptor.next;
}
all_done:
_hurd_sigstate_unlock (ss);
LIBC_CANCEL_RESET (cancel_oldtype);
__mach_port_destroy (__mach_task_self (), wait);
*sig = signo;
return 0;
}
libc_hidden_def (__sigwait)
weak_alias (__sigwait, sigwait)
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