109 lines
2.9 KiB
C
109 lines
2.9 KiB
C
/* Implementation of sigwait function from POSIX.1c.
|
|
Copyright (C) 1996, 1997, 1999, 2000, 2002 Free Software Foundation, Inc.
|
|
This file is part of the GNU C Library.
|
|
Contributed by Ulrich Drepper <drepper@cygnus.com>, 1996.
|
|
|
|
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 <signal.h>
|
|
#include <stddef.h> /* For NULL. */
|
|
#include <sysdep-cancel.h>
|
|
|
|
/* This is our dummy signal handler we use here. */
|
|
static void ignore_signal (int sig);
|
|
|
|
/* Place where to remember which signal we got. Please note that this
|
|
implementation cannot be used for the threaded libc. The
|
|
libpthread must provide an own version. */
|
|
static int was_sig;
|
|
|
|
|
|
static int
|
|
do_sigwait (const sigset_t *set, int *sig)
|
|
{
|
|
sigset_t tmp_mask;
|
|
struct sigaction saved[NSIG];
|
|
struct sigaction action;
|
|
int save_errno;
|
|
int this;
|
|
|
|
/* Prepare set. */
|
|
__sigfillset (&tmp_mask);
|
|
|
|
/* Unblock all signals in the SET and register our nice handler. */
|
|
action.sa_handler = ignore_signal;
|
|
action.sa_flags = 0;
|
|
__sigfillset (&action.sa_mask); /* Block all signals for handler. */
|
|
|
|
/* Make sure we recognize error conditions by setting WAS_SIG to a
|
|
value which does not describe a legal signal number. */
|
|
was_sig = -1;
|
|
|
|
for (this = 1; this < NSIG; ++this)
|
|
if (__sigismember (set, this))
|
|
{
|
|
/* Unblock this signal. */
|
|
__sigdelset (&tmp_mask, this);
|
|
|
|
/* Register temporary action handler. */
|
|
if (__sigaction (this, &action, &saved[this]) != 0)
|
|
goto restore_handler;
|
|
}
|
|
|
|
/* Now we can wait for signals. */
|
|
__sigsuspend (&tmp_mask);
|
|
|
|
restore_handler:
|
|
save_errno = errno;
|
|
|
|
while (--this >= 1)
|
|
if (__sigismember (set, this))
|
|
/* We ignore errors here since we must restore all handlers. */
|
|
__sigaction (this, &saved[this], NULL);
|
|
|
|
__set_errno (save_errno);
|
|
|
|
/* Store the result and return. */
|
|
*sig = was_sig;
|
|
return was_sig == -1 ? -1 : 0;
|
|
}
|
|
|
|
|
|
int
|
|
__sigwait (const sigset_t *set, int *sig)
|
|
{
|
|
if (SINGLE_THREAD_P)
|
|
return do_sigwait (set, sig);
|
|
|
|
int oldtype = LIBC_CANCEL_ASYNC ();
|
|
|
|
int result = do_sigwait (set, sig);
|
|
|
|
LIBC_CANCEL_RESET (oldtype);
|
|
|
|
return result;
|
|
}
|
|
libc_hidden_def (__sigwait)
|
|
weak_alias (__sigwait, sigwait)
|
|
|
|
|
|
static void
|
|
ignore_signal (int sig)
|
|
{
|
|
/* Remember the signal. */
|
|
was_sig = sig;
|
|
}
|