thr_sig.c revision 114772 
1/*
2 * Copyright (c) 2003 Jeffrey Roberson <jeff@freebsd.org>
3 * Copyright (c) 2003 Jonathan Mini <mini@freebsd.org>
4 * All rights reserved.
5 *
6 * Redistribution and use in source and binary forms, with or without
7 * modification, are permitted provided that the following conditions
8 * are met:
9 * 1. Redistributions of source code must retain the above copyright
10 *    notice unmodified, this list of conditions, and the following
11 *    disclaimer.
12 * 2. Redistributions in binary form must reproduce the above copyright
13 *    notice, this list of conditions and the following disclaimer in the
14 *    documentation and/or other materials provided with the distribution.
15 *
16 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
17 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
18 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
19 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
20 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
21 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
22 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
23 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
24 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
25 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
26 *
27 * $FreeBSD: head/lib/libthr/thread/thr_sig.c 114772 2003-05-06 02:30:52Z mtm $
28 */
29
30#include <sys/param.h>
31#include <sys/types.h>
32#include <sys/signalvar.h>
33#include <signal.h>
34#include <fcntl.h>
35#include <unistd.h>
36#include <setjmp.h>
37#include <errno.h>
38#include <pthread.h>
39#include "thr_private.h"
40
41/* #define DEBUG_SIGNAL */
42#ifdef DEBUG_SIGNAL
43#define DBG_MSG		stdout_debug
44#else
45#define DBG_MSG(x...)
46#endif
47
48__weak_reference(_sigprocmask, sigprocmask);
49
50int
51_sigprocmask(int how, const sigset_t *set, sigset_t *oset)
52{
53	sigset_t new;
54
55	/*
56	 * Make sure applications can't unblock our synchronization
57	 * signal. We always want to take this with sigwait().
58	 */
59	if (set != NULL) {
60		new = *set;
61		switch (how) {
62		case SIG_BLOCK:
63		case SIG_SETMASK:
64			SIGADDSET(new, SIGTHR);
65			break;
66		case SIG_UNBLOCK:
67			SIGDELSET(new, SIGTHR);
68			break;
69		default:
70			break;
71		}
72		set = &new;
73	}
74
75	return (__sys_sigprocmask(how, set, oset));
76}
77
78__weak_reference(_pthread_sigmask, pthread_sigmask);
79
80int
81_pthread_sigmask(int how, const sigset_t *set, sigset_t *oset)
82{
83	int error;
84
85	/*
86	 * This always sets the mask on the current thread.
87	 */
88	error = sigprocmask(how, set, oset);
89
90	/*
91	 * pthread_sigmask returns errno or success while sigprocmask returns
92	 * -1 and sets errno.
93	 */
94	if (error == -1)
95		error = errno;
96
97	return (error);
98}
99
100
101__weak_reference(_pthread_kill, pthread_kill);
102
103int
104_pthread_kill(pthread_t pthread, int sig)
105{
106
107	if (_thread_initial == NULL)
108		_thread_init();
109	return (thr_kill(pthread->thr_id, sig));
110}
111
112/*
113 * User thread signal handler wrapper.
114 */
115void
116_thread_sig_wrapper(int sig, siginfo_t *info, ucontext_t *context)
117{
118	struct pthread_state_data psd;
119	__siginfohandler_t *handler;
120
121	GIANT_LOCK(curthread);
122	/* Save the thread's previous state. */
123	curthread->data = psd.psd_wait_data;
124	curthread->state = psd.psd_state;
125	curthread->flags = psd.psd_flags;
126
127	/*
128	 * Do a little cleanup handling for those threads in
129	 * queues before calling the signal handler.  Signals
130	 * for these threads are temporarily blocked until
131	 * after cleanup handling.
132	 */
133	switch (psd.psd_state) {
134	case PS_COND_WAIT:
135		_cond_wait_backout(curthread);
136		psd.psd_state = PS_RUNNING;
137		break;
138
139	case PS_MUTEX_WAIT:
140		/* _mutex_lock_backout(curthread); XXXTHR */
141		psd.psd_state = PS_RUNNING;
142		break;
143
144	default:
145		break;
146	}
147
148	if (_thread_sigact[sig -1].sa_handler != NULL) {
149		GIANT_UNLOCK(curthread);
150		handler = (__siginfohandler_t *)
151			_thread_sigact[sig - 1].sa_handler;
152		handler(sig, info, context);
153		GIANT_LOCK(curthread);
154	}
155
156        /* Restore the signal frame. */
157	psd.psd_wait_data = curthread->data;
158	psd.psd_state = curthread->state;
159	psd.psd_flags = curthread->flags &
160	    (PTHREAD_FLAGS_PRIVATE | PTHREAD_FLAGS_TRACE);
161	GIANT_UNLOCK(curthread);
162}
163