1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
|
/* $OpenBSD: uthread_sigwait.c,v 1.9 2001/08/21 19:24:53 fgsch Exp $ */
/*
* 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: uthread_sigwait.c,v 1.10 1999/09/30 14:51:31 marcel Exp $
*/
#include <signal.h>
#include <errno.h>
#ifdef _THREAD_SAFE
#include <pthread.h>
#include "pthread_private.h"
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;
/* This is a cancellation point: */
_thread_enter_cancellation_point();
/*
* 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. */
if ((tempset = (curthread->sigpend & waitset)) != 0) {
/* Enter a loop to find a pending signal: */
for (i = 1; i < NSIG; i++) {
if (sigismember (&tempset, i))
break;
}
/* Clear the pending signal: */
sigdelset(&curthread->sigpend,i);
/* Return the signal number to the caller: */
*sig = i;
/* No longer in a cancellation point: */
_thread_leave_cancellation_point();
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.
*/
curthread->data.sigwait = &waitset;
/* Wait for a signal: */
_thread_kern_sched_state(PS_SIGWAIT, __FILE__, __LINE__);
/* 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;
}
/* 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;
}
}
/* No longer in a cancellation point: */
_thread_leave_cancellation_point();
/* Return the completion status: */
return (ret);
}
#endif
|
