1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
|
/*
* Copyright (c) 2006, 2015, Oracle and/or its affiliates. All rights reserved.
* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
*
* This code is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License version 2 only, as
* published by the Free Software Foundation.
*
* This code is distributed in the hope that it will be useful, but WITHOUT
* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
* version 2 for more details (a copy is included in the LICENSE file that
* accompanied this code).
*
* You should have received a copy of the GNU General Public License version
* 2 along with this work; if not, write to the Free Software Foundation,
* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
*
* Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
* or visit www.oracle.com if you need additional information or have any
* questions.
*/
/*
* @test
* @bug 6475157
* @summary Tests deadlock in simultaneous connection and connector-server close
* @author Eamonn McManus
*/
/* This test is somewhat dependent on implementation details. If it suddenly
* starts failing after a rewrite of the RMIConnectorServer code, you should
* consider whether it is still relevant.
*/
import java.io.IOException;
import java.lang.management.ManagementFactory;
import java.lang.management.ThreadInfo;
import java.lang.management.ThreadMXBean;
import java.util.concurrent.Exchanger;
import javax.management.MBeanServer;
import javax.management.remote.JMXServiceURL;
import javax.management.remote.rmi.RMIConnection;
import javax.management.remote.rmi.RMIConnectorServer;
import javax.management.remote.rmi.RMIJRMPServerImpl;
public class ConnectorStopDeadlockTest {
private static String failure;
private static RMIConnectorServer connectorServer;
public static void main(String[] args) throws Exception {
JMXServiceURL url = new JMXServiceURL("service:jmx:rmi://");
MBeanServer mbs = ManagementFactory.getPlatformMBeanServer();
RMIJRMPServerImplSub impl = new RMIJRMPServerImplSub();
System.out.println("Creating connectorServer");
connectorServer = new RMIConnectorServer(url, null, impl, mbs);
System.out.println("Starting connectorServer");
connectorServer.start();
System.out.println("Making client");
RMIConnection cc = impl.newClient(null);
System.out.println("Closing client");
cc.close();
if (connectorServer.isActive()) {
System.out.println("Stopping connectorServer");
connectorServer.stop();
}
if (failure == null)
System.out.println("TEST PASSED, no deadlock");
else
System.out.println("TEST FAILED");
}
static void fail(Throwable e) {
System.out.println("FAILED WITH EXCEPTION: " + e);
e.printStackTrace(System.out);
failure = e.toString();
}
static void fail(String s) {
System.out.println("FAILED: " + s);
failure = s;
}
// static MonitorInfo[] threadLocks(Thread t) {
// ThreadMXBean tm = ManagementFactory.getThreadMXBean();
// ThreadInfo[] tis = tm.getThreadInfo(new long[] {t.getId()}, true, true);
// if (tis[0] == null)
// return null;
// else
// return tis[0].getLockedMonitors();
// }
//
// static void showLocks(Thread t) {
// System.out.println("Locks for " + t.getName() + ":");
// MonitorInfo[] mis = threadLocks(t);
// if (mis == null)
// System.out.println(" (no longer exists)");
// else if (mis.length == 0)
// System.out.println(" (none)");
// else {
// for (MonitorInfo mi : mis)
// System.out.println(" " + mi);
// }
// }
// Wait until thread t blocks waiting for a lock held by the calling thread,
// or until it exits.
static void waitForBlock(Thread t) {
Thread currentThread = Thread.currentThread();
System.out.println("waiting for thread " + t.getName() + " to block " +
"on a lock held by thread " + currentThread.getName());
ThreadMXBean tm = ManagementFactory.getThreadMXBean();
while (true) {
ThreadInfo ti = tm.getThreadInfo(t.getId());
if (ti == null) {
System.out.println(" thread has exited");
return;
}
if (ti.getLockOwnerId() == currentThread.getId()) {
System.out.println(" thread now blocked");
return;
}
Thread.yield();
}
}
public static class RMIJRMPServerImplSub extends RMIJRMPServerImpl {
RMIJRMPServerImplSub() throws IOException {
super(0, null, null, null);
}
public RMIConnection makeClient() throws IOException {
return super.makeClient("connection id", null);
}
@Override
protected void clientClosed(RMIConnection conn) throws IOException {
System.out.println("clientClosed, will call connectorServer.stop");
final Exchanger<Void> x = new Exchanger<Void>();
Thread t = new Thread() {
public void run() {
try {
connectorServer.stop();
} catch (Exception e) {
fail(e);
}
}
};
t.setName("connectorServer.stop");
t.start();
waitForBlock(t);
/* If this thread is synchronized on RMIServerImpl, then
* the thread that does connectorServer.stop will acquire
* the clientList lock and then block waiting for the RMIServerImpl
* lock. Our call to super.clientClosed will then deadlock because
* it needs to acquire the clientList lock.
*/
System.out.println("calling super.clientClosed");
System.out.flush();
super.clientClosed(conn);
}
}
}
|
