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/* Copyright (C) 1996 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 Library General Public License as
published by the Free Software Foundation; either version 2 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
Library General Public License for more details.
You should have received a copy of the GNU Library General Public
License along with the GNU C Library; see the file COPYING.LIB. If
not, write to the Free Software Foundation, Inc., 675 Mass Ave,
Cambridge, MA 02139, USA. */
#include <errno.h>
#include <hurd.h>
#include <hurd/signal.h>
#include <hurd/msg.h>
#include <hurd/sigpreempt.h>
#include <assert.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;
int signo = 0;
struct hurd_signal_preempter preempter;
jmp_buf buf;
mach_port_t wait;
mach_msg_header_t msg;
sighandler_t
preempt_fun (struct hurd_signal_preempter *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));
/* Make sure this signal is unblocked */
__sigdelset (&ss->blocked, signo);
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;
ss = _hurd_self_sigstate ();
__spin_lock (&ss->lock);
/* See if one of these signals is currently pending */
if (ss->pending & mask)
{
for (signo = 1; signo < NSIG; signo++)
if (__sigismember (&ss->pending, signo))
{
__sigdelset (&ss->pending, signo);
goto all_done;
}
/* Huh? Where'd it go? */
abort ();
}
/* Wait for one of them to show up */
if (!setjmp (buf))
{
/* Make the preempter */
preempter.signals = mask;
preempter.first = 0;
preempter.last = -1;
preempter.preempter = preempt_fun;
preempter.handler = handler;
/* Install this preempter */
preempter.next = ss->preempters;
ss->preempters = &preempter;
__spin_unlock (&ss->lock);
/* Wait. */
__mach_msg (&msg, MACH_RCV_MSG, 0, sizeof (msg), wait,
MACH_MSG_TIMEOUT_NONE, MACH_PORT_NULL);
abort ();
}
else
{
assert (signo);
__spin_lock (&ss->lock);
/* Delete our preempter. */
assert (ss->preempters == &preempter);
ss->preempters = preempter.next;
}
all_done:
/* Cause the pointless side-effect. */
__sigfillset (&ss->blocked);
for (signo = 1; signo < NSIG; signo++)
if (__sigismember (&mask, signo))
__sigdelset (&ss->blocked, signo);
spin_unlock (&ss->lock);
__mach_port_destroy (__mach_task_self (), wait);
*sig = signo;
return 0;
}
weak_alias (__sigwait, sigwait)
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