com.sun.tools.sjavac.server.IdleResetSjavac Maven / Gradle / Ivy
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/*
* Copyright (c) 2014, 2016, 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
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*/
package com.sun.tools.sjavac.server;
import com.sun.tools.javac.main.Main.Result;
import com.sun.tools.sjavac.Log;
import java.util.Timer;
import java.util.TimerTask;
/**
* An sjavac implementation that keeps track of idleness and shuts down the
* given Terminable upon idleness timeout.
*
* An idleness timeout kicks in {@code idleTimeout} milliseconds after the last
* request is completed.
*
* This is NOT part of any supported API.
* If you write code that depends on this, you do so at your own risk.
* This code and its internal interfaces are subject to change or
* deletion without notice.
*/
public class IdleResetSjavac implements Sjavac {
private final Sjavac delegate;
private final Terminable toShutdown;
private final Timer idlenessTimer = new Timer();
private final long idleTimeout;
private int outstandingCalls = 0;
// Class invariant: idlenessTimerTask != null <-> idlenessTimerTask is scheduled
private TimerTask idlenessTimerTask;
public IdleResetSjavac(Sjavac delegate,
Terminable toShutdown,
long idleTimeout) {
this.delegate = delegate;
this.toShutdown = toShutdown;
this.idleTimeout = idleTimeout;
scheduleTimeout();
}
@Override
public Result compile(String[] args) {
startCall();
try {
return delegate.compile(args);
} finally {
endCall();
}
}
private synchronized void startCall() {
// Was there no outstanding calls before this call?
if (++outstandingCalls == 1) {
// Then the timer task must have been scheduled
if (idlenessTimerTask == null)
throw new IllegalStateException("Idle timeout already cancelled");
// Cancel timeout task
idlenessTimerTask.cancel();
idlenessTimerTask = null;
}
}
private synchronized void endCall() {
if (--outstandingCalls == 0) {
// No more outstanding calls. Schedule timeout.
scheduleTimeout();
}
}
private void scheduleTimeout() {
if (idlenessTimerTask != null)
throw new IllegalStateException("Idle timeout already scheduled");
idlenessTimerTask = new TimerTask() {
public void run() {
Log.setLogForCurrentThread(ServerMain.getErrorLog());
toShutdown.shutdown("Server has been idle for " + (idleTimeout / 1000) + " seconds.");
}
};
idlenessTimer.schedule(idlenessTimerTask, idleTimeout);
}
@Override
public void shutdown() {
idlenessTimer.cancel();
delegate.shutdown();
}
}