/*
* Copyright 2010-2011 Ning, Inc.
*
* Ning 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 com.ning.billing.util.queue;
import java.util.concurrent.CountDownLatch;
import java.util.concurrent.Executor;
import java.util.concurrent.TimeUnit;
import java.util.concurrent.atomic.AtomicBoolean;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.weakref.jmx.Managed;
import com.ning.billing.util.config.PersistentQueueConfig;
import com.ning.billing.util.jackson.ObjectMapper;
public abstract class PersistentQueueBase implements QueueLifecycle {
private static final Logger log = LoggerFactory.getLogger(PersistentQueueBase.class);
private static final long waitTimeoutMs = 15L * 1000L; // 15 seconds
private final int nbThreads;
private final Executor executor;
private final String svcQName;
protected final PersistentQueueConfig config;
private boolean isProcessingEvents;
private int curActiveThreads;
protected static final ObjectMapper objectMapper = new ObjectMapper();
private final AtomicBoolean isStarted = new AtomicBoolean(false);
// Allow to disable/re-enable notitifcation processing through JMX
private final AtomicBoolean isProcessingSuspended;
public PersistentQueueBase(final String svcQName, final Executor executor, final int nbThreads, final PersistentQueueConfig config) {
this.executor = executor;
this.nbThreads = nbThreads;
this.svcQName = svcQName;
this.config = config;
this.isProcessingEvents = false;
this.curActiveThreads = 0;
this.isProcessingSuspended = new AtomicBoolean(false);
}
@Override
public void startQueue() {
if (config.isProcessingOff() || !isStarted.compareAndSet(false, true)) {
return;
}
isProcessingEvents = true;
curActiveThreads = 0;
final PersistentQueueBase thePersistentQ = this;
final CountDownLatch doneInitialization = new CountDownLatch(nbThreads);
log.info(String.format("%s: Starting with %d threads",
svcQName, nbThreads));
for (int i = 0; i < nbThreads; i++) {
executor.execute(new Runnable() {
@Override
public void run() {
log.info(String.format("%s: Thread %s [%d] starting",
svcQName,
Thread.currentThread().getName(),
Thread.currentThread().getId()));
synchronized (thePersistentQ) {
curActiveThreads++;
}
doneInitialization.countDown();
try {
while (true) {
if (!isProcessingEvents) {
break;
}
try {
if (!isProcessingSuspended.get()) {
doProcessEvents();
}
} catch (Exception e) {
log.warn(String.format("%s: Thread %s [%d] got an exception, catching and moving on...",
svcQName,
Thread.currentThread().getName(),
Thread.currentThread().getId()), e);
}
sleepALittle();
}
} catch (InterruptedException e) {
log.info(String.format("%s: Thread %s got interrupted, exting... ", svcQName, Thread.currentThread().getName()));
} catch (Throwable e) {
log.error(String.format("%s: Thread %s got an exception, exting... ", svcQName, Thread.currentThread().getName()), e);
} finally {
log.info(String.format("%s: Thread %s has exited", svcQName, Thread.currentThread().getName()));
synchronized (thePersistentQ) {
curActiveThreads--;
thePersistentQ.notify();
}
}
}
private void sleepALittle() throws InterruptedException {
Thread.sleep(config.getSleepTimeMs());
}
});
}
try {
final boolean success = doneInitialization.await(waitTimeoutMs, TimeUnit.MILLISECONDS);
if (!success) {
log.warn(String.format("%s: Failed to wait for all threads to be started, got %d/%d", svcQName, (nbThreads - doneInitialization.getCount()), nbThreads));
} else {
log.info(String.format("%s: Done waiting for all threads to be started, got %d/%d", svcQName, (nbThreads - doneInitialization.getCount()), nbThreads));
}
} catch (InterruptedException e) {
log.warn(String.format("%s: Start sequence, got interrupted", svcQName));
}
}
@Override
public void stopQueue() {
if (config.isProcessingOff() || !isStarted.compareAndSet(true, false)) {
return;
}
int remaining = 0;
try {
synchronized (this) {
isProcessingEvents = false;
final long ini = System.currentTimeMillis();
long remainingWaitTimeMs = waitTimeoutMs;
while (curActiveThreads > 0 && remainingWaitTimeMs > 0) {
wait(1000);
remainingWaitTimeMs = waitTimeoutMs - (System.currentTimeMillis() - ini);
}
remaining = curActiveThreads;
}
} catch (InterruptedException ignore) {
log.info(String.format("%s: Stop sequence has been interrupted, remaining active threads = %d", svcQName, curActiveThreads));
} finally {
if (remaining > 0) {
log.error(String.format("%s: Stop sequence completed with %d active remaing threads", svcQName, curActiveThreads));
} else {
log.info(String.format("%s: Stop sequence completed with %d active remaing threads", svcQName, curActiveThreads));
}
curActiveThreads = 0;
}
}
@Managed(description="suspend processing for all notifications")
public void suspendNotificationProcessing() {
isProcessingSuspended.set(true);
}
@Managed(description="resume processing for all notifications")
public void resumeNotificationProcessing() {
isProcessingSuspended.set(false);
}
@Managed(description="check whether notification processing is suspended")
public boolean isNotificationProcessingSuspended() {
return isProcessingSuspended.get();
}
// TODO PIERRE Better API?
public static <T> T deserializeEvent(final String className, final String json) {
try {
final Class<?> claz = Class.forName(className);
return (T) objectMapper.readValue(json, claz);
} catch (Exception e) {
log.error(String.format("Failed to deserialize json object %s for class %s", json, className), e);
return null;
}
}
public abstract int doProcessEvents();
public boolean isStarted() {
return isStarted.get();
}
}