2 * Copyright (c) 1997 John Birrell <jb@cimlogic.com.au>.
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
8 * 1. Redistributions of source code must retain the above copyright
9 * notice, this list of conditions and the following disclaimer.
10 * 2. Redistributions in binary form must reproduce the above copyright
11 * notice, this list of conditions and the following disclaimer in the
12 * documentation and/or other materials provided with the distribution.
13 * 3. All advertising materials mentioning features or use of this software
14 * must display the following acknowledgement:
15 * This product includes software developed by John Birrell.
16 * 4. Neither the name of the author nor the names of any co-contributors
17 * may be used to endorse or promote products derived from this software
18 * without specific prior written permission.
20 * THIS SOFTWARE IS PROVIDED BY JOHN BIRRELL AND CONTRIBUTORS ``AS IS'' AND
21 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
22 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
23 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
24 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
25 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
26 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
27 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
28 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
29 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
35 #include <sys/param.h>
36 #include <sys/signalvar.h>
40 #include "pthread_private.h"
43 sigwait(const sigset_t * set, int *sig)
47 sigset_t tempset, waitset;
50 _thread_enter_cancellation_point();
52 * Specify the thread kernel signal handler.
54 act.sa_handler = (void (*) ()) _thread_sig_handler;
55 act.sa_flags = SA_RESTART;
58 /* Ensure the scheduling signal is masked: */
59 sigaddset(&act.sa_mask, _SCHED_SIGNAL);
62 * Initialize the set of signals that will be waited on:
66 /* These signals can't be waited on. */
67 sigdelset(&waitset, SIGKILL);
68 sigdelset(&waitset, SIGSTOP);
69 sigdelset(&waitset, _SCHED_SIGNAL);
70 sigdelset(&waitset, SIGCHLD);
71 sigdelset(&waitset, SIGINFO);
73 /* Check to see if a pending signal is in the wait mask. */
74 tempset = _thread_run->sigpend;
75 SIGSETOR(tempset, _process_sigpending);
76 SIGSETAND(tempset, waitset);
77 if (SIGNOTEMPTY(tempset)) {
78 /* Enter a loop to find a pending signal: */
79 for (i = 1; i < NSIG; i++) {
80 if (sigismember (&tempset, i))
84 /* Clear the pending signal: */
85 if (sigismember(&_thread_run->sigpend,i))
86 sigdelset(&_thread_run->sigpend,i);
88 sigdelset(&_process_sigpending,i);
90 /* Return the signal number to the caller: */
93 _thread_leave_cancellation_point();
98 * Enter a loop to find the signals that are SIG_DFL. For
99 * these signals we must install a dummy signal handler in
100 * order for the kernel to pass them in to us. POSIX says
101 * that the _application_ must explicitly install a dummy
102 * handler for signals that are SIG_IGN in order to sigwait
103 * on them. Note that SIG_IGN signals are left in the
104 * mask because a subsequent sigaction could enable an
107 for (i = 1; i < NSIG; i++) {
108 if (sigismember(&waitset, i) &&
109 (_thread_sigact[i - 1].sa_handler == SIG_DFL)) {
110 if (_thread_sys_sigaction(i,&act,NULL) != 0)
116 * Save the wait signal mask. The wait signal
117 * mask is independent of the threads signal mask
118 * and requires separate storage.
120 _thread_run->data.sigwait = &waitset;
122 /* Wait for a signal: */
123 _thread_kern_sched_state(PS_SIGWAIT, __FILE__, __LINE__);
125 /* Return the signal number to the caller: */
126 *sig = _thread_run->signo;
129 * Probably unnecessary, but since it's in a union struct
130 * we don't know how it could be used in the future.
132 _thread_run->data.sigwait = NULL;
135 /* Restore the sigactions: */
136 act.sa_handler = SIG_DFL;
137 for (i = 1; i < NSIG; i++) {
138 if (sigismember(&waitset, i) &&
139 (_thread_sigact[i - 1].sa_handler == SIG_DFL)) {
140 if (_thread_sys_sigaction(i,&act,NULL) != 0)
145 _thread_leave_cancellation_point();
146 /* Return the completion status: */