author | ohair |
Tue, 25 May 2010 15:58:33 -0700 | |
changeset 5506 | 202f599c92aa |
parent 3972 | 8942e64cf57d |
child 11264 | 54f2f4c6bd30 |
permissions | -rw-r--r-- |
2 | 1 |
/* |
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* Copyright (c) 2000, 2006, Oracle and/or its affiliates. All rights reserved. |
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* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. |
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* |
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* This code is free software; you can redistribute it and/or modify it |
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* under the terms of the GNU General Public License version 2 only, as |
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* published by the Free Software Foundation. Oracle designates this |
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* particular file as subject to the "Classpath" exception as provided |
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* by Oracle in the LICENSE file that accompanied this code. |
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* |
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* This code is distributed in the hope that it will be useful, but WITHOUT |
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* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or |
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* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License |
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* version 2 for more details (a copy is included in the LICENSE file that |
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* accompanied this code). |
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* |
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* You should have received a copy of the GNU General Public License version |
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* 2 along with this work; if not, write to the Free Software Foundation, |
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* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. |
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* |
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* Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA |
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* or visit www.oracle.com if you need additional information or have any |
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* questions. |
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*/ |
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package sun.awt; |
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import java.awt.AWTEvent; |
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import java.util.Collections; |
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import java.util.HashSet; |
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import java.util.IdentityHashMap; |
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import java.util.Map; |
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import sun.util.logging.PlatformLogger; |
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/** |
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* This class is to let AWT shutdown automatically when a user is done |
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* with AWT. It tracks AWT state using the following parameters: |
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* <ul> |
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* <li><code>peerMap</code> - the map between the existing peer objects |
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* and their associated targets |
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* <li><code>toolkitThreadBusy</code> - whether the toolkit thread |
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* is waiting for a new native event to appear in its queue |
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* or is dispatching an event |
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* <li><code>busyThreadSet</code> - a set of all the event dispatch |
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* threads that are busy at this moment, i.e. those that are not |
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* waiting for a new event to appear in their event queue. |
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* </ul><p> |
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* AWT is considered to be in ready-to-shutdown state when |
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* <code>peerMap</code> is empty and <code>toolkitThreadBusy</code> |
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* is false and <code>busyThreadSet</code> is empty. |
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* The internal AWTAutoShutdown logic secures that the single non-daemon |
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* thread (<code>blockerThread</code>) is running when AWT is not in |
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* ready-to-shutdown state. This blocker thread is to prevent AWT from |
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* exiting since the toolkit thread is now daemon and all the event |
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* dispatch threads are started only when needed. Once it is detected |
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* that AWT is in ready-to-shutdown state this blocker thread waits |
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* for a certain timeout and if AWT state doesn't change during timeout |
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* this blocker thread terminates all the event dispatch threads and |
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* exits. |
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*/ |
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public final class AWTAutoShutdown implements Runnable { |
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private static final AWTAutoShutdown theInstance = new AWTAutoShutdown(); |
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/** |
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* This lock object is used to synchronize shutdown operations. |
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*/ |
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private final Object mainLock = new Object(); |
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/** |
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* This lock object is to secure that when a new blocker thread is |
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* started it will be the first who acquire the main lock after |
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* the thread that created the new blocker released the main lock |
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* by calling lock.wait() to wait for the blocker to start. |
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*/ |
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private final Object activationLock = new Object(); |
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/** |
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* This set keeps references to all the event dispatch threads that |
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* are busy at this moment, i.e. those that are not waiting for a |
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* new event to appear in their event queue. |
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* Access is synchronized on the main lock object. |
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*/ |
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private final HashSet busyThreadSet = new HashSet(7); |
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/** |
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* Indicates whether the toolkit thread is waiting for a new native |
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* event to appear or is dispatching an event. |
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*/ |
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private boolean toolkitThreadBusy = false; |
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/** |
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* This is a map between components and their peers. |
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* we should work with in under activationLock&mainLock lock. |
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*/ |
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private final Map peerMap = new IdentityHashMap(); |
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/** |
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* References the alive non-daemon thread that is currently used |
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* for keeping AWT from exiting. |
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*/ |
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private Thread blockerThread = null; |
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/** |
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* We need this flag to secure that AWT state hasn't changed while |
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* we were waiting for the safety timeout to pass. |
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*/ |
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private boolean timeoutPassed = false; |
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/** |
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* Once we detect that AWT is ready to shutdown we wait for a certain |
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* timeout to pass before stopping event dispatch threads. |
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*/ |
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private static final int SAFETY_TIMEOUT = 1000; |
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/** |
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* Constructor method is intentionally made private to secure |
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* a single instance. Use getInstance() to reference it. |
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* |
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* @see AWTAutoShutdown#getInstance |
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*/ |
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private AWTAutoShutdown() {} |
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/** |
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* Returns reference to a single AWTAutoShutdown instance. |
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*/ |
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public static AWTAutoShutdown getInstance() { |
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return theInstance; |
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} |
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/** |
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* Notify that the toolkit thread is not waiting for a native event |
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* to appear in its queue. |
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* |
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* @see AWTAutoShutdown#notifyToolkitThreadFree |
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* @see AWTAutoShutdown#setToolkitBusy |
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* @see AWTAutoShutdown#isReadyToShutdown |
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*/ |
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public static void notifyToolkitThreadBusy() { |
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getInstance().setToolkitBusy(true); |
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} |
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/** |
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* Notify that the toolkit thread is waiting for a native event |
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* to appear in its queue. |
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* |
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* @see AWTAutoShutdown#notifyToolkitThreadFree |
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* @see AWTAutoShutdown#setToolkitBusy |
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* @see AWTAutoShutdown#isReadyToShutdown |
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*/ |
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public static void notifyToolkitThreadFree() { |
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getInstance().setToolkitBusy(false); |
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} |
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/** |
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* Add a specified thread to the set of busy event dispatch threads. |
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6e77be3973ea
6878284: Sometimes test/javax/swing/system/6799345/TestShutdown.java "hangs"
dcherepanov
parents:
2
diff
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* If this set already contains the specified thread or the thread is null, |
6e77be3973ea
6878284: Sometimes test/javax/swing/system/6799345/TestShutdown.java "hangs"
dcherepanov
parents:
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* the call leaves this set unchanged and returns silently. |
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* |
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* @param thread thread to be added to this set, if not present. |
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* @see AWTAutoShutdown#notifyThreadFree |
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* @see AWTAutoShutdown#isReadyToShutdown |
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*/ |
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public void notifyThreadBusy(final Thread thread) { |
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if (thread == null) { |
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return; |
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dcherepanov
parents:
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} |
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synchronized (activationLock) { |
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synchronized (mainLock) { |
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if (blockerThread == null) { |
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activateBlockerThread(); |
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} else if (isReadyToShutdown()) { |
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mainLock.notifyAll(); |
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timeoutPassed = false; |
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} |
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busyThreadSet.add(thread); |
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} |
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} |
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} |
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/** |
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* Remove a specified thread from the set of busy event dispatch threads. |
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3969
6e77be3973ea
6878284: Sometimes test/javax/swing/system/6799345/TestShutdown.java "hangs"
dcherepanov
parents:
2
diff
changeset
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* If this set doesn't contain the specified thread or the thread is null, |
6e77be3973ea
6878284: Sometimes test/javax/swing/system/6799345/TestShutdown.java "hangs"
dcherepanov
parents:
2
diff
changeset
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* the call leaves this set unchanged and returns silently. |
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* |
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* @param thread thread to be removed from this set, if present. |
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* @see AWTAutoShutdown#notifyThreadBusy |
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* @see AWTAutoShutdown#isReadyToShutdown |
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*/ |
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public void notifyThreadFree(final Thread thread) { |
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6e77be3973ea
6878284: Sometimes test/javax/swing/system/6799345/TestShutdown.java "hangs"
dcherepanov
parents:
2
diff
changeset
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if (thread == null) { |
6e77be3973ea
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dcherepanov
parents:
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return; |
6e77be3973ea
6878284: Sometimes test/javax/swing/system/6799345/TestShutdown.java "hangs"
dcherepanov
parents:
2
diff
changeset
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} |
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synchronized (activationLock) { |
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synchronized (mainLock) { |
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busyThreadSet.remove(thread); |
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if (isReadyToShutdown()) { |
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mainLock.notifyAll(); |
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timeoutPassed = false; |
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} |
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} |
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} |
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} |
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/** |
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* Notify that the peermap has been updated, that means a new peer |
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* has been created or some existing peer has been disposed. |
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* |
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* @see AWTAutoShutdown#isReadyToShutdown |
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*/ |
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void notifyPeerMapUpdated() { |
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synchronized (activationLock) { |
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synchronized (mainLock) { |
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if (!isReadyToShutdown() && blockerThread == null) { |
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activateBlockerThread(); |
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} else { |
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mainLock.notifyAll(); |
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timeoutPassed = false; |
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} |
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} |
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} |
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} |
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/** |
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* Determine whether AWT is currently in ready-to-shutdown state. |
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* AWT is considered to be in ready-to-shutdown state if |
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* <code>peerMap</code> is empty and <code>toolkitThreadBusy</code> |
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* is false and <code>busyThreadSet</code> is empty. |
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* |
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* @return true if AWT is in ready-to-shutdown state. |
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*/ |
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private boolean isReadyToShutdown() { |
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return (!toolkitThreadBusy && |
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peerMap.isEmpty() && |
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busyThreadSet.isEmpty()); |
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} |
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/** |
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* Notify about the toolkit thread state change. |
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* |
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* @param busy true if the toolkit thread state changes from idle |
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* to busy. |
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* @see AWTAutoShutdown#notifyToolkitThreadBusy |
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* @see AWTAutoShutdown#notifyToolkitThreadFree |
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* @see AWTAutoShutdown#isReadyToShutdown |
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*/ |
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private void setToolkitBusy(final boolean busy) { |
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if (busy != toolkitThreadBusy) { |
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synchronized (activationLock) { |
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synchronized (mainLock) { |
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if (busy != toolkitThreadBusy) { |
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if (busy) { |
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if (blockerThread == null) { |
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activateBlockerThread(); |
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} else if (isReadyToShutdown()) { |
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mainLock.notifyAll(); |
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timeoutPassed = false; |
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} |
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toolkitThreadBusy = busy; |
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} else { |
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toolkitThreadBusy = busy; |
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if (isReadyToShutdown()) { |
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mainLock.notifyAll(); |
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timeoutPassed = false; |
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} |
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} |
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} |
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} |
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} |
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} |
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} |
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/** |
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* Implementation of the Runnable interface. |
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* Incapsulates the blocker thread functionality. |
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* |
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* @see AWTAutoShutdown#isReadyToShutdown |
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*/ |
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public void run() { |
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Thread currentThread = Thread.currentThread(); |
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boolean interrupted = false; |
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synchronized (mainLock) { |
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try { |
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/* Notify that the thread is started. */ |
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mainLock.notifyAll(); |
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while (blockerThread == currentThread) { |
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mainLock.wait(); |
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timeoutPassed = false; |
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/* |
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290 |
* This loop is introduced to handle the following case: |
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* it is possible that while we are waiting for the |
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* safety timeout to pass AWT state can change to |
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* not-ready-to-shutdown and back to ready-to-shutdown. |
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* In this case we have to wait once again. |
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295 |
* NOTE: we shouldn't break into the outer loop |
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296 |
* in this case, since we may never be notified |
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297 |
* in an outer infinite wait at this point. |
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*/ |
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299 |
while (isReadyToShutdown()) { |
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300 |
if (timeoutPassed) { |
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301 |
timeoutPassed = false; |
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blockerThread = null; |
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break; |
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} |
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timeoutPassed = true; |
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mainLock.wait(SAFETY_TIMEOUT); |
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} |
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308 |
} |
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309 |
} catch (InterruptedException e) { |
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310 |
interrupted = true; |
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311 |
} finally { |
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312 |
if (blockerThread == currentThread) { |
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blockerThread = null; |
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314 |
} |
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315 |
} |
|
316 |
} |
|
317 |
if (!interrupted) { |
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318 |
AppContext.stopEventDispatchThreads(); |
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319 |
} |
|
320 |
} |
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321 |
||
322 |
static AWTEvent getShutdownEvent() { |
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323 |
return new AWTEvent(getInstance(), 0) {}; |
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324 |
} |
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325 |
||
326 |
/** |
|
327 |
* Creates and starts a new blocker thread. Doesn't return until |
|
328 |
* the new blocker thread starts. |
|
329 |
*/ |
|
330 |
private void activateBlockerThread() { |
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331 |
Thread thread = new Thread(this, "AWT-Shutdown"); |
|
332 |
thread.setDaemon(false); |
|
333 |
blockerThread = thread; |
|
334 |
thread.start(); |
|
335 |
try { |
|
336 |
/* Wait for the blocker thread to start. */ |
|
337 |
mainLock.wait(); |
|
338 |
} catch (InterruptedException e) { |
|
339 |
System.err.println("AWT blocker activation interrupted:"); |
|
340 |
e.printStackTrace(); |
|
341 |
} |
|
342 |
} |
|
343 |
||
344 |
final void registerPeer(final Object target, final Object peer) { |
|
345 |
synchronized (activationLock) { |
|
346 |
synchronized (mainLock) { |
|
347 |
peerMap.put(target, peer); |
|
348 |
notifyPeerMapUpdated(); |
|
349 |
} |
|
350 |
} |
|
351 |
} |
|
352 |
||
353 |
final void unregisterPeer(final Object target, final Object peer) { |
|
354 |
synchronized (activationLock) { |
|
355 |
synchronized (mainLock) { |
|
356 |
if (peerMap.get(target) == peer) { |
|
357 |
peerMap.remove(target); |
|
358 |
notifyPeerMapUpdated(); |
|
359 |
} |
|
360 |
} |
|
361 |
} |
|
362 |
} |
|
363 |
||
364 |
final Object getPeer(final Object target) { |
|
365 |
synchronized (activationLock) { |
|
366 |
synchronized (mainLock) { |
|
367 |
return peerMap.get(target); |
|
368 |
} |
|
369 |
} |
|
370 |
} |
|
371 |
||
3938
ef327bd847c0
6879044: Eliminate the dependency on logging from the AWT/2D/Swing classes
mchung
parents:
2
diff
changeset
|
372 |
final void dumpPeers(final PlatformLogger aLog) { |
2 | 373 |
synchronized (activationLock) { |
374 |
synchronized (mainLock) { |
|
375 |
aLog.fine("Mapped peers:"); |
|
376 |
for (Object key : peerMap.keySet()) { |
|
377 |
aLog.fine(key + "->" + peerMap.get(key)); |
|
378 |
} |
|
379 |
} |
|
380 |
} |
|
381 |
} |
|
382 |
||
383 |
} // class AWTAutoShutdown |