1 /*
2 * Copyright (c) 1998, 2010, 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 "prims/jvm.h"
27 #include "runtime/interfaceSupport.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 /* Check parameterized signals. Don't allow sharing of our interrupt signal */
77 if (sig == os::Solaris::SIGinterrupt()) {
78 return (void *)-1;
79 }
80
81 void* oldHandler = os::signal(sig, newHandler);
82 if (oldHandler == os::user_handler()) {
83 return (void *)2;
84 } else {
85 return oldHandler;
86 }
87 JVM_END
88
89
90 JVM_ENTRY_NO_ENV(jboolean, JVM_RaiseSignal(jint sig))
91 if (ReduceSignalUsage) {
92 // do not allow SHUTDOWN1_SIGNAL,SHUTDOWN2_SIGNAL,SHUTDOWN3_SIGNAL,
93 // BREAK_SIGNAL to be raised when ReduceSignalUsage is set, since
94 // no handler for them is actually registered in JVM or via
95 // JVM_RegisterSignal.
96 if (sig == SHUTDOWN1_SIGNAL || sig == SHUTDOWN2_SIGNAL ||
97 sig == SHUTDOWN3_SIGNAL || sig == BREAK_SIGNAL) {
98 return JNI_FALSE;
99 }
100 }
101 else if ((sig == SHUTDOWN1_SIGNAL || sig == SHUTDOWN2_SIGNAL ||
102 sig == SHUTDOWN3_SIGNAL) && os::Solaris::is_sig_ignored(sig)) {
103 // do not allow SHUTDOWN1_SIGNAL to be raised when SHUTDOWN1_SIGNAL
104 // is ignored, since no handler for them is actually registered in JVM
105 // or via JVM_RegisterSignal.
106 // This also applies for SHUTDOWN2_SIGNAL and SHUTDOWN3_SIGNAL
107 return JNI_FALSE;
108 }
109
110 os::signal_raise(sig);
111 return JNI_TRUE;
112 JVM_END
113
114
115 /*
116 All the defined signal names for Solaris are defined by str2sig().
117
118 NOTE that not all of these names are accepted by our Java implementation
119
120 Via an existing claim by the VM, sigaction restrictions, or
121 the "rules of Unix" some of these names will be rejected at runtime.
122 For example the VM sets up to handle USR1, sigaction returns EINVAL for
123 CANCEL, and Solaris simply doesn't allow catching of KILL.
124
125 Here are the names currently accepted by a user of sun.misc.Signal with
126 1.4.1 (ignoring potential interaction with use of chaining, etc):
127
128 HUP, INT, TRAP, IOT, ABRT, EMT, BUS, SYS, PIPE, ALRM, TERM, USR2,
129 CLD, CHLD, PWR, WINCH, URG, POLL, IO, TSTP, CONT, TTIN, TTOU, VTALRM,
130 PROF, XCPU, XFSZ, FREEZE, THAW, LOST
131 */
132
133 JVM_ENTRY_NO_ENV(jint, JVM_FindSignal(const char *name))
134
135 int sig;
136
137 /* return the named signal's number */
138
139 if(str2sig(name, &sig))
140 return -1;
141 else
142 return sig;
143
144 JVM_END
145
146
147 //Reconciliation History
148 // 1.4 98/10/07 13:39:41 jvm_win32.cpp
149 // 1.6 99/06/22 16:39:00 jvm_win32.cpp
150 //End