| /* |
| * Copyright (c) 2010, 2013, 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. Oracle designates this |
| * particular file as subject to the "Classpath" exception as provided |
| * by Oracle in the LICENSE file that accompanied this code. |
| * |
| * 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. |
| */ |
| |
| package java.awt; |
| |
| import java.util.Timer; |
| import java.util.TimerTask; |
| import java.util.concurrent.atomic.AtomicBoolean; |
| |
| import java.security.PrivilegedAction; |
| import java.security.AccessController; |
| |
| import sun.awt.PeerEvent; |
| |
| import sun.util.logging.PlatformLogger; |
| |
| /** |
| * This utility class is used to suspend execution on a thread |
| * while still allowing {@code EventDispatchThread} to dispatch events. |
| * The API methods of the class are thread-safe. |
| * |
| * @author Anton Tarasov, Artem Ananiev |
| * |
| * @since 1.7 |
| */ |
| class WaitDispatchSupport implements SecondaryLoop { |
| |
| private static final PlatformLogger log = |
| PlatformLogger.getLogger("java.awt.event.WaitDispatchSupport"); |
| |
| private EventDispatchThread dispatchThread; |
| private EventFilter filter; |
| |
| private volatile Conditional extCondition; |
| private volatile Conditional condition; |
| |
| private long interval; |
| // Use a shared daemon timer to serve all the WaitDispatchSupports |
| private static Timer timer; |
| // When this WDS expires, we cancel the timer task leaving the |
| // shared timer up and running |
| private TimerTask timerTask; |
| |
| private AtomicBoolean keepBlockingEDT = new AtomicBoolean(false); |
| private AtomicBoolean keepBlockingCT = new AtomicBoolean(false); |
| private AtomicBoolean afterExit = new AtomicBoolean(false); |
| |
| private static synchronized void initializeTimer() { |
| if (timer == null) { |
| timer = new Timer("AWT-WaitDispatchSupport-Timer", true); |
| } |
| } |
| |
| /** |
| * Creates a {@code WaitDispatchSupport} instance to |
| * serve the given event dispatch thread. |
| * |
| * @param dispatchThread An event dispatch thread that |
| * should not stop dispatching events while waiting |
| * |
| * @since 1.7 |
| */ |
| public WaitDispatchSupport(EventDispatchThread dispatchThread) { |
| this(dispatchThread, null); |
| } |
| |
| /** |
| * Creates a {@code WaitDispatchSupport} instance to |
| * serve the given event dispatch thread. |
| * |
| * @param dispatchThread An event dispatch thread that |
| * should not stop dispatching events while waiting |
| * @param extCond A conditional object used to determine |
| * if the loop should be terminated |
| * |
| * @since 1.7 |
| */ |
| public WaitDispatchSupport(EventDispatchThread dispatchThread, |
| Conditional extCond) |
| { |
| if (dispatchThread == null) { |
| throw new IllegalArgumentException("The dispatchThread can not be null"); |
| } |
| |
| this.dispatchThread = dispatchThread; |
| this.extCondition = extCond; |
| this.condition = new Conditional() { |
| @Override |
| public boolean evaluate() { |
| if (log.isLoggable(PlatformLogger.Level.FINEST)) { |
| log.finest("evaluate(): blockingEDT=" + keepBlockingEDT.get() + |
| ", blockingCT=" + keepBlockingCT.get()); |
| } |
| boolean extEvaluate = |
| (extCondition != null) ? extCondition.evaluate() : true; |
| if (!keepBlockingEDT.get() || !extEvaluate || afterExit.get()) { |
| if (timerTask != null) { |
| timerTask.cancel(); |
| timerTask = null; |
| } |
| return false; |
| } |
| return true; |
| } |
| }; |
| } |
| |
| /** |
| * Creates a {@code WaitDispatchSupport} instance to |
| * serve the given event dispatch thread. |
| * <p> |
| * The {@link EventFilter} is set on the {@code dispatchThread} |
| * while waiting. The filter is removed on completion of the |
| * waiting process. |
| * <p> |
| * |
| * |
| * @param dispatchThread An event dispatch thread that |
| * should not stop dispatching events while waiting |
| * @param filter {@code EventFilter} to be set |
| * @param interval A time interval to wait for. Note that |
| * when the waiting process takes place on EDT |
| * there is no guarantee to stop it in the given time |
| * |
| * @since 1.7 |
| */ |
| public WaitDispatchSupport(EventDispatchThread dispatchThread, |
| Conditional extCondition, |
| EventFilter filter, long interval) |
| { |
| this(dispatchThread, extCondition); |
| this.filter = filter; |
| if (interval < 0) { |
| throw new IllegalArgumentException("The interval value must be >= 0"); |
| } |
| this.interval = interval; |
| if (interval != 0) { |
| initializeTimer(); |
| } |
| } |
| |
| /** |
| * {@inheritDoc} |
| */ |
| @Override |
| public boolean enter() { |
| if (log.isLoggable(PlatformLogger.Level.FINE)) { |
| log.fine("enter(): blockingEDT=" + keepBlockingEDT.get() + |
| ", blockingCT=" + keepBlockingCT.get()); |
| } |
| |
| if (!keepBlockingEDT.compareAndSet(false, true)) { |
| log.fine("The secondary loop is already running, aborting"); |
| return false; |
| } |
| try { |
| if (afterExit.get()) { |
| log.fine("Exit was called already, aborting"); |
| return false; |
| } |
| |
| final Runnable run = new Runnable() { |
| public void run() { |
| log.fine("Starting a new event pump"); |
| if (filter == null) { |
| dispatchThread.pumpEvents(condition); |
| } else { |
| dispatchThread.pumpEventsForFilter(condition, filter); |
| } |
| } |
| }; |
| |
| // We have two mechanisms for blocking: if we're on the |
| // dispatch thread, start a new event pump; if we're |
| // on any other thread, call wait() on the treelock |
| |
| Thread currentThread = Thread.currentThread(); |
| if (currentThread == dispatchThread) { |
| if (log.isLoggable(PlatformLogger.Level.FINEST)) { |
| log.finest("On dispatch thread: " + dispatchThread); |
| } |
| if (interval != 0) { |
| if (log.isLoggable(PlatformLogger.Level.FINEST)) { |
| log.finest("scheduling the timer for " + interval + " ms"); |
| } |
| timer.schedule(timerTask = new TimerTask() { |
| @Override |
| public void run() { |
| if (keepBlockingEDT.compareAndSet(true, false)) { |
| wakeupEDT(); |
| } |
| } |
| }, interval); |
| } |
| // Dispose SequencedEvent we are dispatching on the current |
| // AppContext, to prevent us from hang - see 4531693 for details |
| SequencedEvent currentSE = KeyboardFocusManager. |
| getCurrentKeyboardFocusManager().getCurrentSequencedEvent(); |
| if (currentSE != null) { |
| if (log.isLoggable(PlatformLogger.Level.FINE)) { |
| log.fine("Dispose current SequencedEvent: " + currentSE); |
| } |
| currentSE.dispose(); |
| } |
| // In case the exit() method is called before starting |
| // new event pump it will post the waking event to EDT. |
| // The event will be handled after the new event pump |
| // starts. Thus, the enter() method will not hang. |
| // |
| // Event pump should be privileged. See 6300270. |
| AccessController.doPrivileged(new PrivilegedAction<Void>() { |
| public Void run() { |
| run.run(); |
| return null; |
| } |
| }); |
| } else { |
| if (log.isLoggable(PlatformLogger.Level.FINEST)) { |
| log.finest("On non-dispatch thread: " + currentThread); |
| } |
| keepBlockingCT.set(true); |
| synchronized (getTreeLock()) { |
| if (afterExit.get()) return false; |
| if (filter != null) { |
| dispatchThread.addEventFilter(filter); |
| } |
| try { |
| EventQueue eq = dispatchThread.getEventQueue(); |
| eq.postEvent(new PeerEvent(this, run, PeerEvent.PRIORITY_EVENT)); |
| if (interval > 0) { |
| long currTime = System.currentTimeMillis(); |
| while (keepBlockingCT.get() && |
| ((extCondition != null) ? extCondition.evaluate() : true) && |
| (currTime + interval > System.currentTimeMillis())) |
| { |
| getTreeLock().wait(interval); |
| } |
| } else { |
| while (keepBlockingCT.get() && |
| ((extCondition != null) ? extCondition.evaluate() : true)) |
| { |
| getTreeLock().wait(); |
| } |
| } |
| if (log.isLoggable(PlatformLogger.Level.FINE)) { |
| log.fine("waitDone " + keepBlockingEDT.get() + " " + keepBlockingCT.get()); |
| } |
| } catch (InterruptedException e) { |
| if (log.isLoggable(PlatformLogger.Level.FINE)) { |
| log.fine("Exception caught while waiting: " + e); |
| } |
| } finally { |
| if (filter != null) { |
| dispatchThread.removeEventFilter(filter); |
| } |
| } |
| } |
| } |
| return true; |
| } |
| finally { |
| keepBlockingEDT.set(false); |
| keepBlockingCT.set(false); |
| afterExit.set(false); |
| } |
| } |
| |
| /** |
| * {@inheritDoc} |
| */ |
| public boolean exit() { |
| if (log.isLoggable(PlatformLogger.Level.FINE)) { |
| log.fine("exit(): blockingEDT=" + keepBlockingEDT.get() + |
| ", blockingCT=" + keepBlockingCT.get()); |
| } |
| afterExit.set(true); |
| if (keepBlockingEDT.getAndSet(false)) { |
| wakeupEDT(); |
| return true; |
| } |
| return false; |
| } |
| |
| private static final Object getTreeLock() { |
| return Component.LOCK; |
| } |
| |
| private final Runnable wakingRunnable = new Runnable() { |
| public void run() { |
| log.fine("Wake up EDT"); |
| synchronized (getTreeLock()) { |
| keepBlockingCT.set(false); |
| getTreeLock().notifyAll(); |
| } |
| log.fine("Wake up EDT done"); |
| } |
| }; |
| |
| private void wakeupEDT() { |
| if (log.isLoggable(PlatformLogger.Level.FINEST)) { |
| log.finest("wakeupEDT(): EDT == " + dispatchThread); |
| } |
| EventQueue eq = dispatchThread.getEventQueue(); |
| eq.postEvent(new PeerEvent(this, wakingRunnable, PeerEvent.PRIORITY_EVENT)); |
| } |
| } |