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Source file | Conditionals | Statements | Methods | TOTAL | |||||||||||||||
AbstractSlaveJVM.java | 50% | 90.9% | 100% | 90.3% |
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1 | /*BEGIN_COPYRIGHT_BLOCK | |
2 | * | |
3 | * Copyright (c) 2001-2010, JavaPLT group at Rice University (drjava@rice.edu) | |
4 | * All rights reserved. | |
5 | * | |
6 | * Redistribution and use in source and binary forms, with or without | |
7 | * modification, are permitted provided that the following conditions are met: | |
8 | * * Redistributions of source code must retain the above copyright | |
9 | * notice, this list of conditions and the following disclaimer. | |
10 | * * Redistributions in binary form must reproduce the above copyright | |
11 | * notice, this list of conditions and the following disclaimer in the | |
12 | * documentation and/or other materials provided with the distribution. | |
13 | * * Neither the names of DrJava, the JavaPLT group, Rice University, nor the | |
14 | * names of its contributors may be used to endorse or promote products | |
15 | * derived from this software without specific prior written permission. | |
16 | * | |
17 | * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS | |
18 | * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT | |
19 | * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR | |
20 | * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR | |
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24 | * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF | |
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26 | * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS | |
27 | * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. | |
28 | * | |
29 | * This software is Open Source Initiative approved Open Source Software. | |
30 | * Open Source Initative Approved is a trademark of the Open Source Initiative. | |
31 | * | |
32 | * This file is part of DrJava. Download the current version of this project | |
33 | * from http://www.drjava.org/ or http://sourceforge.net/projects/drjava/ | |
34 | * | |
35 | * END_COPYRIGHT_BLOCK*/ | |
36 | ||
37 | package edu.rice.cs.util.newjvm; | |
38 | ||
39 | import edu.rice.cs.plt.concurrent.ConcurrentUtil; | |
40 | ||
41 | import java.rmi.*; | |
42 | ||
43 | import static edu.rice.cs.plt.debug.DebugUtil.error; | |
44 | import static edu.rice.cs.plt.debug.DebugUtil.debug; | |
45 | ||
46 | /** A partial implementation of a {@link SlaveRemote} that provides the quit functionality and that also periodically | |
47 | * checks if the master is still alive and automatically quits if not. | |
48 | * @version $Id: AbstractSlaveJVM.java 5445 2011-08-17 20:32:57Z rcartwright $ | |
49 | */ | |
50 | public abstract class AbstractSlaveJVM implements SlaveRemote { | |
51 | public static final int CHECK_MAIN_VM_ALIVE_SECONDS = 1; | |
52 | ||
53 | /** Name of the thread to quit the slave. */ | |
54 | private final String _quitSlaveThreadName; | |
55 | /** Name of the thread to periodically poll the master. */ | |
56 | private final String _pollMasterThreadName; | |
57 | private boolean _started; | |
58 | ||
59 | 7 | public AbstractSlaveJVM() { |
60 | 7 | this("Quit SlaveJVM Thread", "Poll MasterJVM Thread"); |
61 | } | |
62 | ||
63 | 187 | public AbstractSlaveJVM(String quitSlaveThreadName, String pollMasterThreadName) { |
64 | 187 | _quitSlaveThreadName = quitSlaveThreadName; |
65 | 187 | _pollMasterThreadName = pollMasterThreadName; |
66 | 187 | _started = false; |
67 | } | |
68 | ||
69 | /** Quits the slave JVM, calling {@link #beforeQuit} before it does. */ | |
70 | 186 | public final synchronized void quit() { |
71 | 186 | beforeQuit(); |
72 | // put exit into another thread to allow this RMI call to return normally. | |
73 | 186 | new Thread(_quitSlaveThreadName) { |
74 | 186 | public void run() { |
75 | // ensure (as best we can) that the quit() RMI call has returned cleanly | |
76 | 186 | synchronized(AbstractSlaveJVM.this) { |
77 | 186 | try { System.exit(0); } |
78 | 0 | catch (RuntimeException e) { error.log("Can't invoke System.exit", e); } |
79 | } | |
80 | } | |
81 | }.start(); | |
82 | } | |
83 | ||
84 | /** Initializes the Slave JVM including starting background thread to periodically poll the master JVM and | |
85 | * automatically quit if it's dead. Synchronized to prevent other method invocations from proceeding before | |
86 | * startup is complete. | |
87 | */ | |
88 | 187 | public final synchronized void start(final MasterRemote master) throws RemoteException { |
89 | 0 | if (_started) { throw new IllegalArgumentException("start() has already been invoked"); } |
90 | 187 | master.checkStillAlive(); // verify that two-way communication works; may throw RemoteException |
91 | ||
92 | 187 | Thread checkMaster = new Thread(_pollMasterThreadName) { |
93 | 187 | public void run() { |
94 | 187 | while (true) { |
95 | 237 | ConcurrentUtil.sleep(CHECK_MAIN_VM_ALIVE_SECONDS*1000); |
96 | 52 | try { master.checkStillAlive(); } |
97 | catch (RemoteException e) { | |
98 | // TODO: This should always be an exceptional situation, but for now | |
99 | // many tests abandon the slave without quitting cleanly. | |
100 | // error.log("Master is no longer available", e); | |
101 | 4 | quit(); |
102 | } | |
103 | } | |
104 | } | |
105 | }; | |
106 | 187 | checkMaster.setDaemon(true); |
107 | 187 | checkMaster.start(); |
108 | 187 | handleStart(master); |
109 | } | |
110 | ||
111 | /** This method is called just before the JVM is quit. It can be overridden to provide cleanup code, etc. */ | |
112 | 186 | protected void beforeQuit() { } |
113 | ||
114 | /** Called when the slave JVM has started running. Subclasses must implement this method. */ | |
115 | protected abstract void handleStart(MasterRemote master); | |
116 | ||
117 | } |
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