/*
* Copyright (C) 2006-2013 Bitronix Software (http://www.bitronix.be)
*
* 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 bitronix.tm.timer;
import bitronix.tm.BitronixTransaction;
import bitronix.tm.TransactionManagerServices;
import bitronix.tm.recovery.Recoverer;
import bitronix.tm.resource.common.XAPool;
import bitronix.tm.utils.ClassLoaderUtils;
import bitronix.tm.utils.MonotonicClock;
import bitronix.tm.utils.Service;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import java.util.Date;
import java.util.HashSet;
import java.util.Set;
import java.util.SortedSet;
import java.util.TreeSet;
import java.util.concurrent.atomic.AtomicBoolean;
import java.util.concurrent.locks.Lock;
import java.util.concurrent.locks.ReentrantLock;
/**
* Timed tasks service.
*
* @author Ludovic Orban
*/
public class TaskScheduler extends Thread implements Service {
private final static Logger log = LoggerFactory.getLogger(TaskScheduler.class);
private final SortedSet<Task> tasks;
private final Lock tasksLock;
private final AtomicBoolean active = new AtomicBoolean(true);
public TaskScheduler() {
// it is up to the ShutdownHandler to control the lifespan of the JVM and give some time for this thread
// to die gracefully, meaning enough time for all tasks to get executed. This is why it is set as daemon.
setDaemon(true);
setName("bitronix-task-scheduler");
SortedSet<Task> tasks;
Lock tasksLock;
try {
@SuppressWarnings("unchecked")
Class<SortedSet<Task>> clazz = ClassLoaderUtils.loadClass("java.util.concurrent.ConcurrentSkipListSet");
tasks = clazz.newInstance();
tasksLock = null;
if (log.isDebugEnabled()) { log.debug("task scheduler backed by ConcurrentSkipListSet"); }
} catch (Exception e) {
tasks = new TreeSet<Task>();
tasksLock = new ReentrantLock();
if (log.isDebugEnabled()) { log.debug("task scheduler backed by locked TreeSet"); }
}
this.tasks = tasks;
this.tasksLock = tasksLock;
}
private void lock() {
if (tasksLock != null) {
tasksLock.lock();
}
}
private void unlock() {
if (tasksLock != null) {
tasksLock.unlock();
}
}
private SortedSet<Task> getSafeIterableTasks() {
if (tasksLock != null) {
return new TreeSet<Task>(tasks);
} else {
return tasks;
}
}
/**
* Get the amount of tasks currently queued.
* @return the amount of tasks currently queued.
*/
public int countTasksQueued() {
lock();
try {
return tasks.size();
} finally {
unlock();
}
}
@Override
public void shutdown() {
boolean wasActive = setActive(false);
if (wasActive) {
try {
long gracefulShutdownTime = TransactionManagerServices.getConfiguration().getGracefulShutdownInterval() * 1000;
if (log.isDebugEnabled()) { log.debug("graceful scheduler shutdown interval: " + gracefulShutdownTime + "ms"); }
join(gracefulShutdownTime);
} catch (InterruptedException ex) {
log.error("could not stop the task scheduler within " + TransactionManagerServices.getConfiguration().getGracefulShutdownInterval() + "s");
}
}
}
/**
* Schedule a task that will mark the transaction as timed out at the specified date. If this method is called
* with the same transaction multiple times, the previous timeout date is dropped and replaced by the new one.
* @param transaction the transaction to mark as timeout.
* @param executionTime the date at which the transaction must be marked.
*/
public void scheduleTransactionTimeout(BitronixTransaction transaction, Date executionTime) {
if (log.isDebugEnabled()) { log.debug("scheduling transaction timeout task on " + transaction + " for " + executionTime); }
if (transaction == null)
throw new IllegalArgumentException("expected a non-null transaction");
if (executionTime == null)
throw new IllegalArgumentException("expected a non-null execution date");
TransactionTimeoutTask task = new TransactionTimeoutTask(transaction, executionTime, this);
addTask(task);
if (log.isDebugEnabled()) { log.debug("scheduled " + task + ", total task(s) queued: " + countTasksQueued()); }
}
/**
* Cancel the task that will mark the transaction as timed out at the specified date.
* @param transaction the transaction to mark as timeout.
*/
public void cancelTransactionTimeout(BitronixTransaction transaction) {
if (log.isDebugEnabled()) { log.debug("cancelling transaction timeout task on " + transaction); }
if (transaction == null)
throw new IllegalArgumentException("expected a non-null transaction");
if (!removeTaskByObject(transaction))
if (log.isDebugEnabled()) { log.debug("no task found based on object " + transaction); }
}
/**
* Schedule a task that will run background recovery at the specified date.
* @param recoverer the recovery implementation to use.
* @param executionTime the date at which the transaction must be marked.
*/
public void scheduleRecovery(Recoverer recoverer, Date executionTime) {
if (log.isDebugEnabled()) { log.debug("scheduling recovery task for " + executionTime); }
if (recoverer == null)
throw new IllegalArgumentException("expected a non-null recoverer");
if (executionTime == null)
throw new IllegalArgumentException("expected a non-null execution date");
RecoveryTask task = new RecoveryTask(recoverer, executionTime, this);
addTask(task);
if (log.isDebugEnabled()) { log.debug("scheduled " + task + ", total task(s) queued: " + countTasksQueued()); }
}
/**
* Cancel the task that will run background recovery at the specified date.
* @param recoverer the recovery implementation to use.
*/
public void cancelRecovery(Recoverer recoverer) {
if (log.isDebugEnabled()) { log.debug("cancelling recovery task"); }
if (!removeTaskByObject(recoverer))
if (log.isDebugEnabled()) { log.debug("no task found based on object " + recoverer); }
}
/**
* Schedule a task that will tell a XA pool to close idle connections. The execution time will be provided by the
* XA pool itself via the {@link bitronix.tm.resource.common.XAPool#getNextShrinkDate()}.
* @param xaPool the XA pool to notify.
*/
public void schedulePoolShrinking(XAPool xaPool) {
Date executionTime = xaPool.getNextShrinkDate();
if (log.isDebugEnabled()) { log.debug("scheduling pool shrinking task on " + xaPool + " for " + executionTime); }
if (executionTime == null)
throw new IllegalArgumentException("expected a non-null execution date");
PoolShrinkingTask task = new PoolShrinkingTask(xaPool, executionTime, this);
addTask(task);
if (log.isDebugEnabled()) { log.debug("scheduled " + task + ", total task(s) queued: " + tasks.size()); }
}
/**
* Cancel the task that will tell a XA pool to close idle connections.
* @param xaPool the XA pool to notify.
*/
public void cancelPoolShrinking(XAPool xaPool) {
if (log.isDebugEnabled()) { log.debug("cancelling pool shrinking task on " + xaPool); }
if (xaPool == null)
throw new IllegalArgumentException("expected a non-null XA pool");
if (!removeTaskByObject(xaPool))
if (log.isDebugEnabled()) { log.debug("no task found based on object " + xaPool); }
}
void addTask(Task task) {
lock();
try {
removeTaskByObject(task.getObject());
tasks.add(task);
} finally {
unlock();
}
}
boolean removeTaskByObject(Object obj) {
lock();
try {
if (log.isDebugEnabled()) { log.debug("removing task by " + obj); }
for (Task task : tasks) {
if (task.getObject() == obj) {
tasks.remove(task);
if (log.isDebugEnabled()) { log.debug("cancelled " + task + ", total task(s) still queued: " + tasks.size()); }
return true;
}
}
return false;
} finally {
unlock();
}
}
boolean setActive(boolean active) {
return this.active.getAndSet(active);
}
private boolean isActive() {
return active.get();
}
@Override
public void run() {
while (isActive()) {
try {
executeElapsedTasks();
Thread.sleep(500); // execute twice per second. That's enough precision.
} catch (InterruptedException ex) {
// ignore
}
}
}
private void executeElapsedTasks() {
lock();
try {
if (this.tasks.isEmpty())
return;
Set<Task> toRemove = new HashSet<Task>();
for (Task task : getSafeIterableTasks()) {
if (task.getExecutionTime().compareTo(new Date(MonotonicClock.currentTimeMillis())) <= 0) {
// if the execution time is now or in the past
if (log.isDebugEnabled()) { log.debug("running " + task); }
try {
task.execute();
if (log.isDebugEnabled()) { log.debug("successfully ran " + task); }
} catch (Exception ex) {
log.warn("error running " + task, ex);
} finally {
toRemove.add(task);
if (log.isDebugEnabled()) { log.debug("total task(s) still queued: " + tasks.size()); }
}
} // if
}
this.tasks.removeAll(toRemove);
} finally {
unlock();
}
}
}