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- /* vi: set sw=4 ts=4: */
- /* sigwait
- *
- * Copyright (C) 2006 by Steven J. Hill <sjhill@realitydiluted.com>
- * Copyright (C) 2003-2005 by Erik Andersen <andersen@uclibc.org>
- *
- * This program 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; see the file COPYING.LIB. If
- * not, see <http://www.gnu.org/licenses/>.
- */
- #define __need_NULL
- #include <stddef.h>
- #include <sys/syscall.h>
- #include <signal.h>
- #include <cancel.h>
- #if defined __NR_rt_sigtimedwait && defined __UCLIBC_HAS_REALTIME__
- #include <string.h>
- /* Return any pending signal or wait for one for the given time. */
- static int __NC(sigwait)(const sigset_t *set, int *sig)
- {
- int ret;
- do
- /* we might as well use sigtimedwait and do not care about cancellation */
- ret = __NC(sigtimedwait)(set, NULL, NULL);
- while (ret == -1 && errno == EINTR);
- if (ret != -1) {
- *sig = ret;
- ret = 0;
- } else
- ret = errno;
- return ret;
- }
- #else /* __NR_rt_sigtimedwait */
- /* variant without REALTIME extensions */
- #include <unistd.h> /* smallint */
- static smallint was_sig; /* obviously not thread-safe */
- static void ignore_signal(int sig)
- {
- was_sig = sig;
- }
- static int __NC(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. */
- /* In Linux (as of 2.6.25), fails only if sig is SIGKILL or SIGSTOP */
- /* (so, will it work correctly if set has, say, SIGSTOP?) */
- if (sigaction (this, &action, &saved[this]) != 0)
- goto restore_handler;
- }
- /* Now we can wait for signals. */
- __NC(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;
- }
- #endif /* __NR_rt_sigtimedwait */
- CANCELLABLE_SYSCALL(int, sigwait, (const sigset_t *set, int *sig), (set, sig))
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