summaryrefslogtreecommitdiff
path: root/lib/libpthread/uthread/uthread_kill.c
blob: dc698ff1660adc278bfc4a2ce8d98a93f88b701b (plain)
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
/*	$OpenBSD: uthread_kill.c,v 1.6 1999/05/26 00:18:24 d 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 REGENTS 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.
 *
 */
#include <errno.h>
#include <signal.h>
#ifdef _THREAD_SAFE
#include <pthread.h>
#include "pthread_private.h"

int
pthread_kill(pthread_t pthread, int sig)
{
	int ret;

	/* Check for invalid signal numbers: */
	if (sig < 0 || sig >= NSIG)
		/* Invalid signal: */
		ret = EINVAL;

	/* Ignored signals get dropped on the floor. */
	else if (_thread_sigact[sig - 1].sa_handler == SIG_IGN)
		ret = 0;

	/* Find the thread in the list of active threads: */
	else if ((ret = _find_thread(pthread)) == 0) {
		/*
		 * Guard against preemption by a scheduling signal.
		 * A change of thread state modifies the waiting
		 * and priority queues.
		 */
		_thread_kern_sched_defer();

		switch (pthread->state) {
		case PS_SIGSUSPEND:
			/*
			 * Only wake up the thread if the signal is unblocked
			 * and there is a handler installed for the signal.
			 */
			if (!sigismember(&pthread->sigmask, sig) &&
			    _thread_sigact[sig - 1].sa_handler != SIG_DFL) {
				/* Change the state of the thread to run: */
				PTHREAD_NEW_STATE(pthread,PS_RUNNING);

				/* Return the signal number: */
				pthread->signo = sig;
			}
			/* Increment the pending signal count: */
			sigaddset(&pthread->sigpend,sig);
			break;

		case PS_SIGWAIT:
			/* Wake up the thread if the signal is blocked. */
			if (sigismember(pthread->data.sigwait, sig)) {
				/* Change the state of the thread to run: */
				PTHREAD_NEW_STATE(pthread,PS_RUNNING);

				/* Return the signal number: */
				pthread->signo = sig;
			} else
				/* Increment the pending signal count. */
				sigaddset(&pthread->sigpend,sig);
			break;

		case PS_SELECT_WAIT:
		case PS_FDR_WAIT:
		case PS_FDW_WAIT:
		case PS_SLEEP_WAIT:
			if (!sigismember(&pthread->sigmask, sig) &&
			    (_thread_sigact[sig - 1].sa_handler != SIG_IGN)) {
				/* Flag the operation as interrupted: */
				pthread->interrupted = 1;

				/* Change the state of the thread to run: */
				PTHREAD_NEW_STATE(pthread,PS_RUNNING);

				/* Return the signal number: */
				pthread->signo = sig;
			} else {
				/* Increment the pending signal count: */
				sigaddset(&pthread->sigpend,sig);
			}
			break;

		default:
			/* Increment the pending signal count: */
			sigaddset(&pthread->sigpend,sig);
			break;
		}

		/*
		 * Reenable preemption and yield if a scheduling signal
		 * occurred while in the critical region.
		 */
		_thread_kern_sched_undefer();
	}

	/* Return the completion status: */
	return (ret);
}
#endif