1 /*
2 * Copyright (c) 1998, 2014, 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. Oracle designates this
8 * particular file as subject to the "Classpath" exception as provided
9 * by Oracle in the LICENSE file that accompanied this code.
10 *
11 * This code is distributed in the hope that it will be useful, but WITHOUT
12 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
13 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
14 * version 2 for more details (a copy is included in the LICENSE file that
15 * accompanied this code).
16 *
17 * You should have received a copy of the GNU General Public License version
18 * 2 along with this work; if not, write to the Free Software Foundation,
19 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
20 *
21 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
22 * or visit www.oracle.com if you need additional information or have any
23 * questions.
24 */
25
26 package jdk.internal.jshell.jdi;
27
28 import java.util.function.Consumer;
29 import com.sun.jdi.*;
30 import com.sun.jdi.event.*;
31
32 /**
33 * Handler of Java Debug Interface events.
34 * Adapted from jdb EventHandler; Handling of events not used by JShell stubbed out.
35 */
36 class JDIEventHandler implements Runnable {
37
38 private final Thread thread;
39 private volatile boolean connected = true;
40 private boolean completed = false;
41 private final VirtualMachine vm;
42 private final Consumer<Boolean> reportVMExit;
43
44 JDIEventHandler(VirtualMachine vm, Consumer<Boolean> reportVMExit) {
45 this.vm = vm;
46 this.reportVMExit = reportVMExit;
47 this.thread = new Thread(this, "event-handler");
48 }
49
50 void start() {
51 thread.start();
52 }
53
54 synchronized void shutdown() {
55 connected = false; // force run() loop termination
56 thread.interrupt();
57 while (!completed) {
58 try {wait();} catch (InterruptedException exc) {}
59 }
60 }
61
62 @Override
63 public void run() {
64 EventQueue queue = vm.eventQueue();
65 while (connected) {
66 try {
67 EventSet eventSet = queue.remove();
68 boolean resumeStoppedApp = false;
69 EventIterator it = eventSet.eventIterator();
70 while (it.hasNext()) {
71 resumeStoppedApp |= handleEvent(it.nextEvent());
72 }
73
74 if (resumeStoppedApp) {
75 eventSet.resume();
76 }
77 } catch (InterruptedException exc) {
78 // Do nothing. Any changes will be seen at top of loop.
79 } catch (VMDisconnectedException discExc) {
80 handleDisconnectedException();
81 break;
82 }
83 }
84 synchronized (this) {
85 completed = true;
86 notifyAll();
87 }
88 }
89
90 private boolean handleEvent(Event event) {
91 if (event instanceof ExceptionEvent) {
92 exceptionEvent(event);
93 } else if (event instanceof WatchpointEvent) {
94 fieldWatchEvent(event);
95 } else if (event instanceof MethodEntryEvent) {
96 methodEntryEvent(event);
97 } else if (event instanceof MethodExitEvent) {
98 methodExitEvent(event);
99 } else if (event instanceof ClassPrepareEvent) {
100 classPrepareEvent(event);
101 } else if (event instanceof ThreadStartEvent) {
102 threadStartEvent(event);
103 } else if (event instanceof ThreadDeathEvent) {
104 threadDeathEvent(event);
105 } else if (event instanceof VMStartEvent) {
106 vmStartEvent(event);
107 return true;
108 } else {
109 handleExitEvent(event);
110 }
111 return true;
112 }
113
114 private boolean vmDied = false;
115
116 private void handleExitEvent(Event event) {
117 if (event instanceof VMDeathEvent) {
118 vmDied = true;
119 } else if (event instanceof VMDisconnectEvent) {
120 connected = false;
121 } else {
122 throw new InternalError("Unexpected event type: " +
123 event.getClass());
124 }
125 reportVMExit.accept(vmDied);
126 }
127
128 private synchronized void handleDisconnectedException() {
129 /*
130 * A VMDisconnectedException has happened while dealing with
131 * another event. We need to flush the event queue, dealing only
132 * with exit events (VMDeath, VMDisconnect) so that we terminate
133 * correctly.
134 */
135 EventQueue queue = vm.eventQueue();
136 while (connected) {
137 try {
138 EventSet eventSet = queue.remove();
139 EventIterator iter = eventSet.eventIterator();
140 while (iter.hasNext()) {
141 handleExitEvent(iter.next());
142 }
143 } catch (InterruptedException exc) {
144 // ignore
145 } catch (InternalError exc) {
146 // ignore
147 }
148 }
149 }
150
151 private void vmStartEvent(Event event) {
152 VMStartEvent se = (VMStartEvent)event;
153 }
154
155 private void methodEntryEvent(Event event) {
156 MethodEntryEvent me = (MethodEntryEvent)event;
157 }
158
159 private void methodExitEvent(Event event) {
160 MethodExitEvent me = (MethodExitEvent)event;
161 }
162
163 private void fieldWatchEvent(Event event) {
164 WatchpointEvent fwe = (WatchpointEvent)event;
165 }
166
167 private void classPrepareEvent(Event event) {
168 ClassPrepareEvent cle = (ClassPrepareEvent)event;
169 }
170
171 private void exceptionEvent(Event event) {
172 ExceptionEvent ee = (ExceptionEvent)event;
173 }
174
175 private void threadDeathEvent(Event event) {
176 ThreadDeathEvent tee = (ThreadDeathEvent)event;
177 }
178
179 private void threadStartEvent(Event event) {
180 ThreadStartEvent tse = (ThreadStartEvent)event;
181 }
182 }