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 "jvm.h"
27 #include "runtime/interfaceSupport.inline.hpp"
28 #include "runtime/osThread.hpp"
29 
30 #include <signal.h>
31 
32 JVM_LEAF(void*, JVM_GetThreadInterruptEvent())
33   return Thread::current()->osthread()->interrupt_event();
34 JVM_END
35 
36 // sun.misc.Signal ///////////////////////////////////////////////////////////
37 // Signal code is mostly copied from classic vm, signals_md.c   1.4 98/08/23
38 /*
39  * This function is included primarily as a debugging aid. If Java is
40  * running in a console window, then pressing <CTRL-BREAK> will cause
41  * the current state of all active threads and monitors to be written
42  * to the console window.
43  */
44 
45 JVM_ENTRY_NO_ENV(void*, JVM_RegisterSignal(jint sig, void* handler))
46   // Copied from classic vm
47   // signals_md.c       1.4 98/08/23
48   void* newHandler = handler == (void *)2
49                    ? os::user_handler()
50                    : handler;
51   switch (sig) {
52    case SIGFPE:
53      return (void *)-1; /* already used by VM */
54    case SIGBREAK:
55      if (!ReduceSignalUsage) return (void *)-1;
56 
57     /* The following signals are used for Shutdown Hooks support. However, if
58        ReduceSignalUsage (-Xrs) is set, Shutdown Hooks must be invoked via
59        System.exit(), Java is not allowed to use these signals, and the the
60        user is allowed to set his own _native_ handler for these signals and
61        invoke System.exit() as needed. Terminator.setup() is avoiding
62        registration of these signals when -Xrs is present. */
63    case SHUTDOWN1_SIGNAL:
64    case SHUTDOWN2_SIGNAL:
65      if (ReduceSignalUsage) return (void*)-1;
66   }
67 
68   void* oldHandler = os::signal(sig, newHandler);
69   if (oldHandler == os::user_handler()) {
70       return (void *)2;
71   } else {
72       return oldHandler;
73   }
74 JVM_END
75 
76 
77 JVM_ENTRY_NO_ENV(jboolean, JVM_RaiseSignal(jint sig))
78   if (ReduceSignalUsage) {
79     // do not allow SHUTDOWN1_SIGNAL,SHUTDOWN2_SIGNAL,BREAK_SIGNAL
80     // to be raised when ReduceSignalUsage is set, since no handler
81     // for them is actually registered in JVM or via JVM_RegisterSignal.
82     if (sig == SHUTDOWN1_SIGNAL || sig == SHUTDOWN2_SIGNAL ||
83         sig == SIGBREAK) {
84       return JNI_FALSE;
85     }
86   }
87   os::signal_raise(sig);
88   return JNI_TRUE;
89 JVM_END
90 
91 
92