1 /*
2 * Copyright (c) 1998, 2015, 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.
8 *
9 * This code is distributed in the hope that it will be useful, but WITHOUT
10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
12 * version 2 for more details (a copy is included in the LICENSE file that
13 * accompanied this code).
14 *
15 * You should have received a copy of the GNU General Public License version
16 * 2 along with this work; if not, write to the Free Software Foundation,
17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
18 *
19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
20 * or visit www.oracle.com if you need additional information or have any
21 * questions.
22 *
23 */
24
25 #include "precompiled.hpp"
26 #include "jvm.h"
27 #include "runtime/interfaceSupport.inline.hpp"
28 #include "runtime/osThread.hpp"
29
30 #include <signal.h>
31
32 // sun.misc.Signal ///////////////////////////////////////////////////////////
33 // Signal code is mostly copied from classic vm, signals_md.c 1.4 98/08/23
34 /*
35 * This function is included primarily as a debugging aid. If Java is
36 * running in a console window, then pressing <CTRL-\\> will cause
37 * the current state of all active threads and monitors to be written
38 * to the console window.
39 */
40
41 JVM_ENTRY_NO_ENV(void*, JVM_RegisterSignal(jint sig, void* handler))
42 // Copied from classic vm
43 // signals_md.c 1.4 98/08/23
44 void* newHandler = handler == (void *)2
45 ? os::user_handler()
46 : handler;
47 switch (sig) {
48 /* The following are already used by the VM. */
49 case SIGFPE:
50 case SIGILL:
51 case SIGSEGV:
52
53 /* The following signal is used by the VM to dump thread stacks unless
54 ReduceSignalUsage is set, in which case the user is allowed to set
55 his own _native_ handler for this signal; thus, in either case,
56 we do not allow JVM_RegisterSignal to change the handler. */
57 case BREAK_SIGNAL:
58 return (void *)-1;
59
60 /* The following signals are used for Shutdown Hooks support. However, if
61 ReduceSignalUsage (-Xrs) is set, Shutdown Hooks must be invoked via
62 System.exit(), Java is not allowed to use these signals, and the the
63 user is allowed to set his own _native_ handler for these signals and
64 invoke System.exit() as needed. Terminator.setup() is avoiding
65 registration of these signals when -Xrs is present.
66 - If the HUP signal is ignored (from the nohup) command, then Java
67 is not allowed to use this signal.
68 */
69 case SHUTDOWN1_SIGNAL:
70 case SHUTDOWN2_SIGNAL:
71 case SHUTDOWN3_SIGNAL:
72 if (ReduceSignalUsage) return (void*)-1;
73 if (os::Solaris::is_sig_ignored(sig)) return (void*)1;
74 }
75
76 void* oldHandler = os::signal(sig, newHandler);
77 if (oldHandler == os::user_handler()) {
78 return (void *)2;
79 } else {
80 return oldHandler;
81 }
82 JVM_END
83
84
85 JVM_ENTRY_NO_ENV(jboolean, JVM_RaiseSignal(jint sig))
86 if (ReduceSignalUsage) {
87 // do not allow SHUTDOWN1_SIGNAL,SHUTDOWN2_SIGNAL,SHUTDOWN3_SIGNAL,
88 // BREAK_SIGNAL to be raised when ReduceSignalUsage is set, since
89 // no handler for them is actually registered in JVM or via
90 // JVM_RegisterSignal.
91 if (sig == SHUTDOWN1_SIGNAL || sig == SHUTDOWN2_SIGNAL ||
92 sig == SHUTDOWN3_SIGNAL || sig == BREAK_SIGNAL) {
93 return JNI_FALSE;
94 }
95 }
96 else if ((sig == SHUTDOWN1_SIGNAL || sig == SHUTDOWN2_SIGNAL ||
97 sig == SHUTDOWN3_SIGNAL) && os::Solaris::is_sig_ignored(sig)) {
98 // do not allow SHUTDOWN1_SIGNAL to be raised when SHUTDOWN1_SIGNAL
99 // is ignored, since no handler for them is actually registered in JVM
100 // or via JVM_RegisterSignal.
101 // This also applies for SHUTDOWN2_SIGNAL and SHUTDOWN3_SIGNAL
102 return JNI_FALSE;
103 }
104
105 os::signal_raise(sig);
106 return JNI_TRUE;
107 JVM_END
108