diff options
Diffstat (limited to 'lib/libpthread/thread/thr_sigwait.c')
| -rw-r--r-- | lib/libpthread/thread/thr_sigwait.c | 175 |
1 files changed, 175 insertions, 0 deletions
diff --git a/lib/libpthread/thread/thr_sigwait.c b/lib/libpthread/thread/thr_sigwait.c new file mode 100644 index 0000000..7b5a31f --- /dev/null +++ b/lib/libpthread/thread/thr_sigwait.c @@ -0,0 +1,175 @@ +//depot/projects/kse/lib/libpthread/thread/thr_sigwait.c#1 - branch change 15154 (text+ko) +/* + * Copyright (c) 1997 John Birrell <jb@cimlogic.com.au>. + * All rights reserved. + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions + * are met: + * 1. Redistributions of source code must retain the above copyright + * notice, this list of conditions and the following disclaimer. + * 2. Redistributions in binary form must reproduce the above copyright + * notice, this list of conditions and the following disclaimer in the + * documentation and/or other materials provided with the distribution. + * 3. All advertising materials mentioning features or use of this software + * must display the following acknowledgement: + * This product includes software developed by John Birrell. + * 4. Neither the name of the author nor the names of any co-contributors + * may be used to endorse or promote products derived from this software + * without specific prior written permission. + * + * THIS SOFTWARE IS PROVIDED BY JOHN BIRRELL AND CONTRIBUTORS ``AS IS'' AND + * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE + * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE + * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE + * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL + * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS + * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) + * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT + * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY + * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF + * SUCH DAMAGE. + * + * $FreeBSD$ + */ +#include <signal.h> +#include <sys/param.h> +#include <sys/signalvar.h> +#include <errno.h> +#include <pthread.h> +#include "thr_private.h" + +__weak_reference(_sigwait, sigwait); + +int +_sigwait(const sigset_t *set, int *sig) +{ + struct pthread *curthread = _get_curthread(); + int ret = 0; + int i; + sigset_t tempset, waitset; + struct sigaction act; + + _thr_enter_cancellation_point(curthread); + + /* + * Specify the thread kernel signal handler. + */ + act.sa_handler = (void (*) ()) _thr_sig_handler; + act.sa_flags = SA_RESTART | SA_SIGINFO; + /* Ensure the signal handler cannot be interrupted by other signals: */ + sigfillset(&act.sa_mask); + + /* + * Initialize the set of signals that will be waited on: + */ + waitset = *set; + + /* These signals can't be waited on. */ + sigdelset(&waitset, SIGKILL); + sigdelset(&waitset, SIGSTOP); + + /* + * Check to see if a pending signal is in the wait mask. + * This has to be atomic. */ + tempset = curthread->sigpend; + SIGSETOR(tempset, _thr_proc_sigpending); + SIGSETAND(tempset, waitset); + if (SIGNOTEMPTY(tempset)) { + /* Enter a loop to find a pending signal: */ + for (i = 1; i < NSIG; i++) { + if (sigismember (&tempset, i)) + break; + } + + /* Clear the pending signal: */ + if (sigismember(&curthread->sigpend,i)) + sigdelset(&curthread->sigpend,i); + else + sigdelset(&_thr_proc_sigpending,i); + + /* Return the signal number to the caller: */ + *sig = i; + + _thr_leave_cancellation_point(curthread); + return (0); + } + + /* + * Lock the array of SIG_DFL wait counts. + */ + THR_LOCK_ACQUIRE(curthread, &_thread_signal_lock); + + /* + * Enter a loop to find the signals that are SIG_DFL. For + * these signals we must install a dummy signal handler in + * order for the kernel to pass them in to us. POSIX says + * that the _application_ must explicitly install a dummy + * handler for signals that are SIG_IGN in order to sigwait + * on them. Note that SIG_IGN signals are left in the + * mask because a subsequent sigaction could enable an + * ignored signal. + */ + sigemptyset(&tempset); + for (i = 1; i < NSIG; i++) { + if (sigismember(&waitset, i) && + (_thread_sigact[i - 1].sa_handler == SIG_DFL)) { + _thread_dfl_count[i]++; + sigaddset(&tempset, i); + if (_thread_dfl_count[i] == 1) { + if (__sys_sigaction(i, &act, NULL) != 0) + ret = -1; + } + } + } + /* Done accessing _thread_dfl_count for now. */ + THR_LOCK_RELEASE(curthread, &_thread_signal_lock); + + if (ret == 0) { + /* + * Save the wait signal mask. The wait signal + * mask is independent of the threads signal mask + * and requires separate storage. + */ + curthread->data.sigwait = &waitset; + + /* Wait for a signal: */ + THR_LOCK_SWITCH(curthread); + THR_SET_STATE(curthread, PS_SIGWAIT); + _thr_sched_switch(curthread); + THR_UNLOCK_SWITCH(curthread); + /* Return the signal number to the caller: */ + *sig = curthread->signo; + + /* + * Probably unnecessary, but since it's in a union struct + * we don't know how it could be used in the future. + */ + curthread->data.sigwait = NULL; + } + + /* + * Relock the array of SIG_DFL wait counts. + */ + THR_LOCK_ACQUIRE(curthread, &_thread_signal_lock); + + /* Restore the sigactions: */ + act.sa_handler = SIG_DFL; + for (i = 1; i < NSIG; i++) { + if (sigismember(&tempset, i)) { + _thread_dfl_count[i]--; + if ((_thread_sigact[i - 1].sa_handler == SIG_DFL) && + (_thread_dfl_count[i] == 0)) { + if (__sys_sigaction(i, &act, NULL) != 0) + ret = -1; + } + } + } + /* Done accessing _thread_dfl_count. */ + THR_LOCK_RELEASE(curthread, &_thread_signal_lock); + + _thr_leave_cancellation_point(curthread); + + /* Return the completion status: */ + return (ret); +} |
