jvm_solaris.cpp revision 1472:c18cbe5936b8 
1/*
2 * Copyright (c) 1998, 2007, 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 "incls/_precompiled.incl"
26#include "incls/_jvm_solaris.cpp.incl"
27
28#include <signal.h>
29
30// sun.misc.Signal ///////////////////////////////////////////////////////////
31// Signal code is mostly copied from classic vm, signals_md.c   1.4 98/08/23
32/*
33 * This function is included primarily as a debugging aid. If Java is
34 * running in a console window, then pressing <CTRL-\\> will cause
35 * the current state of all active threads and monitors to be written
36 * to the console window.
37 */
38
39JVM_ENTRY_NO_ENV(void*, JVM_RegisterSignal(jint sig, void* handler))
40  // Copied from classic vm
41  // signals_md.c       1.4 98/08/23
42  void* newHandler = handler == (void *)2
43                   ? os::user_handler()
44                   : handler;
45  switch (sig) {
46    /* The following are already used by the VM. */
47    case SIGFPE:
48    case SIGILL:
49    case SIGSEGV:
50
51    /* The following signal is used by the VM to dump thread stacks unless
52       ReduceSignalUsage is set, in which case the user is allowed to set
53       his own _native_ handler for this signal; thus, in either case,
54       we do not allow JVM_RegisterSignal to change the handler. */
55    case BREAK_SIGNAL:
56      return (void *)-1;
57
58    /* The following signals are used for Shutdown Hooks support. However, if
59       ReduceSignalUsage (-Xrs) is set, Shutdown Hooks must be invoked via
60       System.exit(), Java is not allowed to use these signals, and the the
61       user is allowed to set his own _native_ handler for these signals and
62       invoke System.exit() as needed. Terminator.setup() is avoiding
63       registration of these signals when -Xrs is present.
64       - If the HUP signal is ignored (from the nohup) command, then Java
65         is not allowed to use this signal.
66     */
67    case SHUTDOWN1_SIGNAL:
68    case SHUTDOWN2_SIGNAL:
69    case SHUTDOWN3_SIGNAL:
70      if (ReduceSignalUsage) return (void*)-1;
71      if (os::Solaris::is_sig_ignored(sig)) return (void*)1;
72  }
73
74  /* Check parameterized signals. Don't allow sharing of our interrupt signal */
75  if (sig == os::Solaris::SIGinterrupt()) {
76      return (void *)-1;
77  }
78
79  void* oldHandler = os::signal(sig, newHandler);
80  if (oldHandler == os::user_handler()) {
81      return (void *)2;
82  } else {
83      return oldHandler;
84  }
85JVM_END
86
87
88JVM_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::Solaris::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  }
107
108  os::signal_raise(sig);
109  return JNI_TRUE;
110JVM_END
111
112
113/*
114  All the defined signal names for Solaris are defined by str2sig().
115
116  NOTE that not all of these names are accepted by our Java implementation
117
118  Via an existing claim by the VM, sigaction restrictions, or
119  the "rules of Unix" some of these names will be rejected at runtime.
120  For example the VM sets up to handle USR1, sigaction returns EINVAL for
121  CANCEL, and Solaris simply doesn't allow catching of KILL.
122
123  Here are the names currently accepted by a user of sun.misc.Signal with
124  1.4.1 (ignoring potential interaction with use of chaining, etc):
125
126      HUP, INT, TRAP, IOT, ABRT, EMT, BUS, SYS, PIPE, ALRM, TERM, USR2,
127      CLD, CHLD, PWR, WINCH, URG, POLL, IO, TSTP, CONT, TTIN, TTOU, VTALRM,
128      PROF, XCPU, XFSZ, FREEZE, THAW, LOST
129*/
130
131JVM_ENTRY_NO_ENV(jint, JVM_FindSignal(const char *name))
132
133  int sig;
134
135  /* return the named signal's number */
136
137  if(str2sig(name, &sig))
138    return -1;
139  else
140    return sig;
141
142JVM_END
143
144
145//Reconciliation History
146// 1.4 98/10/07 13:39:41 jvm_win32.cpp
147// 1.6 99/06/22 16:39:00 jvm_win32.cpp
148//End
149