1 /*
 2  * Copyright (c) 2002, 2020, Oracle and/or its affiliates. All rights reserved.
 3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
 4  *
 5  * This code is free software; you can redistribute it and/or modify it
 6  * under the terms of the GNU General Public License version 2 only, as
 7  * published by the Free Software Foundation.  Oracle designates this
 8  * particular file as subject to the "Classpath" exception as provided
 9  * by Oracle in the LICENSE file that accompanied this code.
10  *
11  * This code is distributed in the hope that it will be useful, but WITHOUT
12  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
13  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
14  * version 2 for more details (a copy is included in the LICENSE file that
15  * accompanied this code).
16  *
17  * You should have received a copy of the GNU General Public License version
18  * 2 along with this work; if not, write to the Free Software Foundation,
19  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
20  *
21  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
22  * or visit www.oracle.com if you need additional information or have any
23  * questions.
24  */
25 
26 #include <sys/types.h>
27 #include <string.h>
28 #include "jni.h"
29 #include "jni_util.h"
30 #include "jvm.h"
31 #include "jlong.h"
32 #include "sun_nio_ch_NativeThread.h"
33 #include "nio_util.h"
34 #include <signal.h>
35 #include <pthread.h>
36 
37 #ifdef __linux__
38   /* Also defined in net/linux_close.c */
39   #define INTERRUPT_SIGNAL (SIGRTMAX - 2)
40 #elif defined(_AIX)
41   /* Also defined in net/aix_close.c */
42   #define INTERRUPT_SIGNAL (SIGRTMAX - 1)
43 #elif defined(_ALLBSD_SOURCE)
44   /* Also defined in net/bsd_close.c */
45   #define INTERRUPT_SIGNAL SIGIO
46 #else
47   #error "missing platform-specific definition here"
48 #endif
49 
50 static void
51 nullHandler(int sig)
52 {
53 }
54 
55 JNIEXPORT void JNICALL
56 Java_sun_nio_ch_NativeThread_init(JNIEnv *env, jclass cl)
57 {
58     /* Install the null handler for INTERRUPT_SIGNAL.  This might overwrite the
59      * handler previously installed by <platform>_close.c, but that's okay
60      * since neither handler actually does anything.  We install our own
61      * handler here simply out of paranoia; ultimately the two mechanisms
62      * should somehow be unified, perhaps within the VM.
63      */
64 
65     sigset_t ss;
66     struct sigaction sa, osa;
67     sa.sa_handler = nullHandler;
68     sa.sa_flags = 0;
69     sigemptyset(&sa.sa_mask);
70     if (sigaction(INTERRUPT_SIGNAL, &sa, &osa) < 0)
71         JNU_ThrowIOExceptionWithLastError(env, "sigaction");
72 }
73 
74 JNIEXPORT jlong JNICALL
75 Java_sun_nio_ch_NativeThread_current0(JNIEnv *env, jclass cl)
76 {
77     return (jlong)pthread_self();
78 }
79 
80 JNIEXPORT void JNICALL
81 Java_sun_nio_ch_NativeThread_signal0(JNIEnv *env, jclass cl, jlong thread)
82 {
83     int ret;
84     ret = pthread_kill((pthread_t)thread, INTERRUPT_SIGNAL);
85 #ifdef MACOSX
86     if (ret != 0 && ret != ESRCH)
87 #else
88     if (ret != 0)
89 #endif
90         JNU_ThrowIOExceptionWithLastError(env, "Thread signal failed");
91 }