/*
* Copyright 2002-2009 the original author or authors.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package org.springframework.scheduling.concurrent;
import java.util.Date;
import java.util.concurrent.Delayed;
import java.util.concurrent.ExecutionException;
import java.util.concurrent.ScheduledExecutorService;
import java.util.concurrent.ScheduledFuture;
import java.util.concurrent.TimeUnit;
import java.util.concurrent.TimeoutException;
import org.springframework.scheduling.Trigger;
import org.springframework.scheduling.support.DelegatingErrorHandlingRunnable;
import org.springframework.scheduling.support.SimpleTriggerContext;
import org.springframework.util.ErrorHandler;
/**
* Internal adapter that reschedules an underlying {@link Runnable} according
* to the next execution time suggested by a given {@link Trigger}.
*
* <p>Necessary because a native {@link ScheduledExecutorService} supports
* delay-driven execution only. The flexibility of the {@link Trigger} interface
* will be translated onto a delay for the next execution time (repeatedly).
*
* @author Juergen Hoeller
* @author Mark Fisher
* @since 3.0
*/
class ReschedulingRunnable extends DelegatingErrorHandlingRunnable implements ScheduledFuture<Object> {
private final Trigger trigger;
private final SimpleTriggerContext triggerContext = new SimpleTriggerContext();
private final ScheduledExecutorService executor;
private volatile ScheduledFuture currentFuture;
private volatile Date scheduledExecutionTime;
private final Object triggerContextMonitor = new Object();
public ReschedulingRunnable(Runnable delegate, Trigger trigger, ScheduledExecutorService executor, ErrorHandler errorHandler) {
super(delegate, errorHandler);
this.trigger = trigger;
this.executor = executor;
}
public ScheduledFuture schedule() {
synchronized (this.triggerContextMonitor) {
this.scheduledExecutionTime = this.trigger.nextExecutionTime(this.triggerContext);
if (this.scheduledExecutionTime == null) {
return null;
}
long initialDelay = this.scheduledExecutionTime.getTime() - System.currentTimeMillis();
this.currentFuture = this.executor.schedule(this, initialDelay, TimeUnit.MILLISECONDS);
return this;
}
}
@Override
public void run() {
Date actualExecutionTime = new Date();
super.run();
Date completionTime = new Date();
synchronized (this.triggerContextMonitor) {
this.triggerContext.update(this.scheduledExecutionTime, actualExecutionTime, completionTime);
}
if (!this.currentFuture.isCancelled()) {
schedule();
}
}
public boolean cancel(boolean mayInterruptIfRunning) {
return this.currentFuture.cancel(mayInterruptIfRunning);
}
public boolean isCancelled() {
return this.currentFuture.isCancelled();
}
public boolean isDone() {
return this.currentFuture.isDone();
}
public Object get() throws InterruptedException, ExecutionException {
return this.currentFuture.get();
}
public Object get(long timeout, TimeUnit unit) throws InterruptedException, ExecutionException, TimeoutException {
return this.currentFuture.get(timeout, unit);
}
public long getDelay(TimeUnit unit) {
return this.currentFuture.getDelay(unit);
}
public int compareTo(Delayed other) {
if (this == other) {
return 0;
}
long diff = getDelay(TimeUnit.MILLISECONDS) - other.getDelay(TimeUnit.MILLISECONDS);
return (diff == 0 ? 0 : ((diff < 0)? -1 : 1));
}
}
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