/**
* Licensed to Jasig under one or more contributor license
* agreements. See the NOTICE file distributed with this work
* for additional information regarding copyright ownership.
* Jasig licenses this file to you 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.jasig.portal.utils.threading;
import java.lang.reflect.Method;
import java.util.Date;
import java.util.concurrent.Callable;
import java.util.concurrent.Delayed;
import java.util.concurrent.ExecutionException;
import java.util.concurrent.ExecutorService;
import java.util.concurrent.Future;
import java.util.concurrent.RejectedExecutionException;
import java.util.concurrent.ScheduledFuture;
import java.util.concurrent.TimeUnit;
import java.util.concurrent.TimeoutException;
import org.joda.time.ReadableDuration;
import org.springframework.scheduling.SchedulingTaskExecutor;
import org.springframework.scheduling.TaskScheduler;
import org.springframework.scheduling.Trigger;
import org.springframework.scheduling.TriggerContext;
import org.springframework.scheduling.concurrent.ThreadPoolTaskScheduler;
import org.springframework.scheduling.support.ScheduledMethodRunnable;
/**
* Scheduling thread pool that upon invocation of the scheduled task immediately
* delegates execution to another {@link ExecutorService}. Also adds a configurable
* start delay to scheduled tasks
*
* @author Eric Dalquist
* @version $Revision$
*/
public class DelegatingThreadPoolTaskScheduler extends ThreadPoolTaskScheduler
implements TaskScheduler, SchedulingTaskExecutor {
private static final long serialVersionUID = 1L;
private volatile long initialized = System.currentTimeMillis();
private volatile long lastStartDelay = 0;
private ExecutorService executorService;
private long initialDelay = 0;
public void setExecutorService(ExecutorService executorService) {
this.executorService = executorService;
}
/**
* delay to add to the start date for all scheduled tasks
*
* @param initialDelay Delay before starting ANY scheduled task
*/
public void setInitialDelay(ReadableDuration initialDelay) {
this.initialDelay = initialDelay.getMillis();
this.lastStartDelay = this.initialDelay;
}
@Override
public void afterPropertiesSet() {
this.initialized = System.currentTimeMillis();
super.afterPropertiesSet();
}
/**
* @return the additional start delay to add to any scheduled task
*/
protected long getAdditionalStartDelay() {
//Only bother recalculating the start delay if the last time it was resulted in a delay
if (this.lastStartDelay != 0) {
this.lastStartDelay = Math.max(0, this.initialDelay - (System.currentTimeMillis() - this.initialized));
logger.debug("Calculated additionalStartDelay of: " + this.lastStartDelay);
}
return this.lastStartDelay;
}
protected Date getDelayedStartDate(Date startDate) {
final long additionalStartDelay = this.getAdditionalStartDelay();
if (additionalStartDelay > 0) {
final Date newStartDate = new Date(startDate.getTime() + additionalStartDelay);
logger.debug("Updated startDate with additionalStartDelay from " + startDate + " to " + newStartDate);
return newStartDate;
}
return startDate;
}
protected Runnable wrapRunnable(Runnable task) {
if (task instanceof ScheduledMethodRunnable) {
final Method method = ((ScheduledMethodRunnable) task).getMethod();
final String methodName = method.getName();
return new ThreadNamingRunnable("-" + methodName, task);
}
return task;
}
@Override
public void execute(Runnable task, long startTimeout) {
task = wrapRunnable(task);
final DelegatingRunnable delegatingRunnable = new DelegatingRunnable(this.executorService, task);
super.execute(delegatingRunnable, startTimeout);
}
@Override
public Future<?> submit(Runnable task) {
task = wrapRunnable(task);
final DelegatingRunnable delegatingRunnable = new DelegatingRunnable(this.executorService, task);
return super.submit(delegatingRunnable);
}
@Override
public <T> Future<T> submit(Callable<T> task) {
final DelegatingCallable<T> delegatingCallable = new DelegatingCallable<T>(this.executorService, task);
final Future<Future<T>> future = super.submit(delegatingCallable);
return new DelegatingForwardingFuture<T>(future);
}
@Override
public void execute(Runnable task) {
task = wrapRunnable(task);
final DelegatingRunnable delegatingRunnable = new DelegatingRunnable(this.executorService, task);
super.execute(delegatingRunnable);
}
@Override
public ScheduledFuture<Object> schedule(Runnable task, final Trigger trigger) {
task = wrapRunnable(task);
//Wrap the trigger so that the first call to nextExecutionTime adds in the additionalStartDelay
final Trigger wrappedTrigger = new Trigger() {
boolean firstExecution = false;
@Override
public Date nextExecutionTime(TriggerContext triggerContext) {
Date nextExecutionTime = trigger.nextExecutionTime(triggerContext);
if (nextExecutionTime == null) {
return null;
}
if (firstExecution) {
nextExecutionTime = getDelayedStartDate(nextExecutionTime);
firstExecution = true;
}
return nextExecutionTime;
}
};
final DelegatingRunnable delegatingRunnable = new DelegatingRunnable(this.executorService, task);
@SuppressWarnings("unchecked")
final ScheduledFuture<ScheduledFuture<Object>> future = super.schedule(delegatingRunnable, wrappedTrigger);
return new DelegatingForwardingScheduledFuture<Object>(future);
}
@Override
public ScheduledFuture<Object> schedule(Runnable task, Date startTime) {
startTime = getDelayedStartDate(startTime);
final DelegatingRunnable delegatingRunnable = new DelegatingRunnable(this.executorService, task);
@SuppressWarnings("unchecked")
final ScheduledFuture<ScheduledFuture<Object>> future = super.schedule(delegatingRunnable, startTime);
return new DelegatingForwardingScheduledFuture<Object>(future);
}
@Override
public ScheduledFuture<Object> scheduleAtFixedRate(Runnable task, Date startTime, long period) {
task = wrapRunnable(task);
startTime = getDelayedStartDate(startTime); //Add scheduled task delay
startTime = new Date(startTime.getTime() + period); //Add period to inital run time
final DelegatingRunnable delegatingRunnable = new DelegatingRunnable(this.executorService, task);
@SuppressWarnings("unchecked")
final ScheduledFuture<ScheduledFuture<Object>> future = super.scheduleAtFixedRate(delegatingRunnable, startTime, period);
return new DelegatingForwardingScheduledFuture<Object>(future);
}
@Override
public ScheduledFuture<Object> scheduleAtFixedRate(Runnable task, long period) {
task = wrapRunnable(task);
final long additionalStartDelay = this.getAdditionalStartDelay();
if (additionalStartDelay > 0) {
//If there is an additional delay use the alternate call which includes a startTime
return this.scheduleAtFixedRate(task, new Date(), period);
}
final DelegatingRunnable delegatingRunnable = new DelegatingRunnable(this.executorService, task);
@SuppressWarnings("unchecked")
final ScheduledFuture<ScheduledFuture<Object>> future = super.scheduleAtFixedRate(delegatingRunnable, period);
return new DelegatingForwardingScheduledFuture<Object>(future);
}
@Override
public ScheduledFuture<Object> scheduleWithFixedDelay(Runnable task, Date startTime, long delay) {
task = wrapRunnable(task);
startTime = getDelayedStartDate(startTime); //Add scheduled task delay
startTime = new Date(startTime.getTime() + delay); //Add period to inital run time
final DelegatingRunnable delegatingRunnable = new DelegatingRunnable(this.executorService, task);
@SuppressWarnings("unchecked")
final ScheduledFuture<ScheduledFuture<Object>> future = super.scheduleWithFixedDelay(delegatingRunnable, startTime, delay);
return new DelegatingForwardingScheduledFuture<Object>(future);
}
@Override
public ScheduledFuture<Object> scheduleWithFixedDelay(Runnable task, long delay) {
task = wrapRunnable(task);
final long additionalStartDelay = this.getAdditionalStartDelay();
if (additionalStartDelay > 0) {
//If there is an additional delay use the alternate call which includes a startTime
return this.scheduleWithFixedDelay(task, new Date(), delay);
}
final DelegatingRunnable delegatingRunnable = new DelegatingRunnable(this.executorService, task);
@SuppressWarnings("unchecked")
final ScheduledFuture<ScheduledFuture<Object>> future = super.scheduleWithFixedDelay(delegatingRunnable, delay);
return new DelegatingForwardingScheduledFuture<Object>(future);
}
private static class DelegatingRunnable implements Runnable {
private final ExecutorService executorService;
private final Runnable runnable;
public DelegatingRunnable(ExecutorService executorService, Runnable runnable) {
this.executorService = executorService;
this.runnable = runnable;
}
@Override
public void run() {
try {
executorService.submit(this.runnable);
}
catch (RejectedExecutionException e) {
throw new RejectedExecutionException("Failed to execute scheduled task " + this.runnable, e);
}
}
}
private static class DelegatingCallable<T> implements Callable<Future<T>> {
private final ExecutorService executorService;
private final Callable<T> callable;
public DelegatingCallable(ExecutorService executorService, Callable<T> callable) {
this.executorService = executorService;
this.callable = callable;
}
@Override
public Future<T> call() throws Exception {
try {
return executorService.submit(this.callable);
}
catch (RejectedExecutionException e) {
throw new RejectedExecutionException("Failed to execute scheduled task " + this.callable, e);
}
}
}
private static class DelegatingForwardingFuture<V> implements Future<V> {
private final Future<? extends Future<V>> future;
public DelegatingForwardingFuture(Future<? extends Future<V>> future) {
this.future = future;
}
@Override
public V get() throws InterruptedException, ExecutionException {
return this.future.get().get();
}
@Override
public V get(long timeout, TimeUnit unit) throws InterruptedException, ExecutionException, TimeoutException {
return this.future.get(timeout, unit).get(timeout, unit);
}
@Override
public boolean cancel(boolean mayInterruptIfRunning) {
return this.future.cancel(mayInterruptIfRunning);
}
@Override
public boolean isCancelled() {
return this.future.isCancelled();
}
@Override
public boolean isDone() {
return this.future.isDone();
}
}
private static class DelegatingForwardingScheduledFuture<V> extends DelegatingForwardingFuture<V> implements ScheduledFuture<V> {
private final ScheduledFuture<ScheduledFuture<V>> future;
public DelegatingForwardingScheduledFuture(ScheduledFuture<ScheduledFuture<V>> scheduledFuture) {
super(scheduledFuture);
this.future = scheduledFuture;
}
@Override
public long getDelay(TimeUnit unit) {
return this.future.getDelay(unit);
}
@Override
public int compareTo(Delayed o) {
return this.future.compareTo(o);
}
}
}