diff options
Diffstat (limited to 'lib/libpthread/thread/thr_sigwait.c')
| -rw-r--r-- | lib/libpthread/thread/thr_sigwait.c | 143 |
1 files changed, 143 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..e08b298 --- /dev/null +++ b/lib/libpthread/thread/thr_sigwait.c @@ -0,0 +1,143 @@ +/* + * 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> +#ifdef _THREAD_SAFE +#include <pthread.h> +#include "pthread_private.h" + +int +sigwait(const sigset_t * set, int *sig) +{ + int ret = 0; + int i; + sigset_t tempset, waitset; + struct sigaction act; + + /* + * Specify the thread kernel signal handler. + */ + act.sa_handler = (void (*) ()) _thread_sig_handler; + act.sa_flags = SA_RESTART; + act.sa_mask = *set; + + /* Ensure the scheduling signal is masked: */ + sigaddset(&act.sa_mask, _SCHED_SIGNAL); + + /* + * 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); + sigdelset(&waitset, _SCHED_SIGNAL); + sigdelset(&waitset, SIGCHLD); + sigdelset(&waitset, SIGINFO); + + /* Check to see if a pending signal is in the wait mask. */ + tempset = _thread_run->sigpend; + 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: */ + sigdelset(&_thread_run->sigpend,i); + + /* Return the signal number to the caller: */ + *sig = i; + + return (0); + } + + /* + * 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. + */ + for (i = 1; i < NSIG; i++) { + if (sigismember(&waitset, i) && + (_thread_sigact[i - 1].sa_handler == SIG_DFL)) { + if (_thread_sys_sigaction(i,&act,NULL) != 0) + ret = -1; + } + } + if (ret == 0) { + + /* + * Save the wait signal mask. The wait signal + * mask is independent of the threads signal mask + * and requires separate storage. + */ + _thread_run->data.sigwait = &waitset; + + /* Wait for a signal: */ + _thread_kern_sched_state(PS_SIGWAIT, __FILE__, __LINE__); + + /* Return the signal number to the caller: */ + *sig = _thread_run->signo; + + /* + * Probably unnecessary, but since it's in a union struct + * we don't know how it could be used in the future. + */ + _thread_run->data.sigwait = NULL; + } + + /* Restore the sigactions: */ + act.sa_handler = SIG_DFL; + for (i = 1; i < NSIG; i++) { + if (sigismember(&waitset, i) && + (_thread_sigact[i - 1].sa_handler == SIG_DFL)) { + if (_thread_sys_sigaction(i,&act,NULL) != 0) + ret = -1; + } + } + + /* Return the completion status: */ + return (ret); +} +#endif |
