Thu, 24 May 2018 17:06:56 +0800
Merge
1 /*
2 * Copyright (c) 1999, 2011, 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 */
25 #include "precompiled.hpp"
26 #include "prims/jvm.h"
27 #include "runtime/interfaceSupport.hpp"
28 #include "runtime/osThread.hpp"
30 #include <signal.h>
33 // sun.misc.Signal ///////////////////////////////////////////////////////////
34 // Signal code is mostly copied from classic vm, signals_md.c 1.4 98/08/23
35 /*
36 * This function is included primarily as a debugging aid. If Java is
37 * running in a console window, then pressing <CTRL-\\> will cause
38 * the current state of all active threads and monitors to be written
39 * to the console window.
40 */
42 JVM_ENTRY_NO_ENV(void*, JVM_RegisterSignal(jint sig, void* handler))
43 // Copied from classic vm
44 // signals_md.c 1.4 98/08/23
45 void* newHandler = handler == (void *)2
46 ? os::user_handler()
47 : handler;
48 switch (sig) {
49 /* The following are already used by the VM. */
50 case INTERRUPT_SIGNAL:
51 case SIGFPE:
52 case SIGILL:
53 case SIGSEGV:
55 /* The following signal is used by the VM to dump thread stacks unless
56 ReduceSignalUsage is set, in which case the user is allowed to set
57 his own _native_ handler for this signal; thus, in either case,
58 we do not allow JVM_RegisterSignal to change the handler. */
59 case BREAK_SIGNAL:
60 return (void *)-1;
62 /* The following signals are used for Shutdown Hooks support. However, if
63 ReduceSignalUsage (-Xrs) is set, Shutdown Hooks must be invoked via
64 System.exit(), Java is not allowed to use these signals, and the the
65 user is allowed to set his own _native_ handler for these signals and
66 invoke System.exit() as needed. Terminator.setup() is avoiding
67 registration of these signals when -Xrs is present.
68 - If the HUP signal is ignored (from the nohup) command, then Java
69 is not allowed to use this signal.
70 */
72 case SHUTDOWN1_SIGNAL:
73 case SHUTDOWN2_SIGNAL:
74 case SHUTDOWN3_SIGNAL:
75 if (ReduceSignalUsage) return (void*)-1;
76 if (os::Bsd::is_sig_ignored(sig)) return (void*)1;
77 }
79 void* oldHandler = os::signal(sig, newHandler);
80 if (oldHandler == os::user_handler()) {
81 return (void *)2;
82 } else {
83 return oldHandler;
84 }
85 JVM_END
88 JVM_ENTRY_NO_ENV(jboolean, JVM_RaiseSignal(jint sig))
89 if (ReduceSignalUsage) {
90 // do not allow SHUTDOWN1_SIGNAL,SHUTDOWN2_SIGNAL,SHUTDOWN3_SIGNAL,
91 // BREAK_SIGNAL to be raised when ReduceSignalUsage is set, since
92 // no handler for them is actually registered in JVM or via
93 // JVM_RegisterSignal.
94 if (sig == SHUTDOWN1_SIGNAL || sig == SHUTDOWN2_SIGNAL ||
95 sig == SHUTDOWN3_SIGNAL || sig == BREAK_SIGNAL) {
96 return JNI_FALSE;
97 }
98 }
99 else if ((sig == SHUTDOWN1_SIGNAL || sig == SHUTDOWN2_SIGNAL ||
100 sig == SHUTDOWN3_SIGNAL) && os::Bsd::is_sig_ignored(sig)) {
101 // do not allow SHUTDOWN1_SIGNAL to be raised when SHUTDOWN1_SIGNAL
102 // is ignored, since no handler for them is actually registered in JVM
103 // or via JVM_RegisterSignal.
104 // This also applies for SHUTDOWN2_SIGNAL and SHUTDOWN3_SIGNAL
105 return JNI_FALSE;
106 }
108 os::signal_raise(sig);
109 return JNI_TRUE;
110 JVM_END
112 /*
113 All the defined signal names for Bsd.
115 NOTE that not all of these names are accepted by our Java implementation
117 Via an existing claim by the VM, sigaction restrictions, or
118 the "rules of Unix" some of these names will be rejected at runtime.
119 For example the VM sets up to handle USR1, sigaction returns EINVAL for
120 STOP, and Bsd simply doesn't allow catching of KILL.
122 Here are the names currently accepted by a user of sun.misc.Signal with
123 1.4.1 (ignoring potential interaction with use of chaining, etc):
125 HUP, INT, TRAP, ABRT, IOT, BUS, USR2, PIPE, ALRM, TERM, STKFLT,
126 CLD, CHLD, CONT, TSTP, TTIN, TTOU, URG, XCPU, XFSZ, VTALRM, PROF,
127 WINCH, POLL, IO, PWR, SYS
129 */
131 struct siglabel {
132 const char *name;
133 int number;
134 };
136 struct siglabel siglabels[] = {
137 /* derived from /usr/include/bits/signum.h on RH7.2 */
138 "HUP", SIGHUP, /* Hangup (POSIX). */
139 "INT", SIGINT, /* Interrupt (ANSI). */
140 "QUIT", SIGQUIT, /* Quit (POSIX). */
141 "ILL", SIGILL, /* Illegal instruction (ANSI). */
142 "TRAP", SIGTRAP, /* Trace trap (POSIX). */
143 "ABRT", SIGABRT, /* Abort (ANSI). */
144 "EMT", SIGEMT, /* EMT trap */
145 "FPE", SIGFPE, /* Floating-point exception (ANSI). */
146 "KILL", SIGKILL, /* Kill, unblockable (POSIX). */
147 "BUS", SIGBUS, /* BUS error (4.2 BSD). */
148 "SEGV", SIGSEGV, /* Segmentation violation (ANSI). */
149 "SYS", SIGSYS, /* Bad system call. Only on some Bsden! */
150 "PIPE", SIGPIPE, /* Broken pipe (POSIX). */
151 "ALRM", SIGALRM, /* Alarm clock (POSIX). */
152 "TERM", SIGTERM, /* Termination (ANSI). */
153 "URG", SIGURG, /* Urgent condition on socket (4.2 BSD). */
154 "STOP", SIGSTOP, /* Stop, unblockable (POSIX). */
155 "TSTP", SIGTSTP, /* Keyboard stop (POSIX). */
156 "CONT", SIGCONT, /* Continue (POSIX). */
157 "CHLD", SIGCHLD, /* Child status has changed (POSIX). */
158 "TTIN", SIGTTIN, /* Background read from tty (POSIX). */
159 "TTOU", SIGTTOU, /* Background write to tty (POSIX). */
160 "IO", SIGIO, /* I/O now possible (4.2 BSD). */
161 "XCPU", SIGXCPU, /* CPU limit exceeded (4.2 BSD). */
162 "XFSZ", SIGXFSZ, /* File size limit exceeded (4.2 BSD). */
163 "VTALRM", SIGVTALRM, /* Virtual alarm clock (4.2 BSD). */
164 "PROF", SIGPROF, /* Profiling alarm clock (4.2 BSD). */
165 "WINCH", SIGWINCH, /* Window size change (4.3 BSD, Sun). */
166 "INFO", SIGINFO, /* Information request. */
167 "USR1", SIGUSR1, /* User-defined signal 1 (POSIX). */
168 "USR2", SIGUSR2 /* User-defined signal 2 (POSIX). */
169 };
171 JVM_ENTRY_NO_ENV(jint, JVM_FindSignal(const char *name))
173 /* find and return the named signal's number */
175 for(uint i=0; i<ARRAY_SIZE(siglabels); i++)
176 if(!strcmp(name, siglabels[i].name))
177 return siglabels[i].number;
179 return -1;
181 JVM_END
183 // used by os::exception_name()
184 extern bool signal_name(int signo, char* buf, size_t len) {
185 for(uint i = 0; i < ARRAY_SIZE(siglabels); i++) {
186 if (signo == siglabels[i].number) {
187 jio_snprintf(buf, len, "SIG%s", siglabels[i].name);
188 return true;
189 }
190 }
191 return false;
192 }