/*
* Licensed to the Apache Software Foundation (ASF) under one
* or more contributor license agreements. See the NOTICE file
* distributed with this work for additional information
* regarding copyright ownership. The ASF 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.apache.cassandra.scheduler;
import java.util.concurrent.SynchronousQueue;
import java.util.concurrent.TimeoutException;
import java.util.concurrent.TimeUnit;
import java.lang.management.ManagementFactory;
import javax.management.MBeanServer;
import javax.management.ObjectName;
import org.apache.cassandra.metrics.LatencyMetrics;
class WeightedQueue implements WeightedQueueMBean
{
private final LatencyMetrics metric;
public final String key;
public final int weight;
private final SynchronousQueue<Entry> queue;
public WeightedQueue(String key, int weight)
{
this.key = key;
this.weight = weight;
this.queue = new SynchronousQueue<Entry>(true);
this.metric = new LatencyMetrics("org.apache.cassandra.metrics", "scheduler", "WeightedQueue", key);
}
public void register()
{
// expose monitoring data
MBeanServer mbs = ManagementFactory.getPlatformMBeanServer();
try
{
mbs.registerMBean(this, new ObjectName("org.apache.cassandra.scheduler:type=WeightedQueue,queue=" + key));
}
catch (Exception e)
{
throw new RuntimeException(e);
}
}
public void put(Thread t, long timeoutMS) throws InterruptedException, TimeoutException
{
if (!queue.offer(new WeightedQueue.Entry(t), timeoutMS, TimeUnit.MILLISECONDS))
throw new TimeoutException("Failed to acquire request scheduler slot for '" + key + "'");
}
public Thread poll()
{
Entry e = queue.poll();
if (e == null)
return null;
metric.addNano(System.nanoTime() - e.creationTime);
return e.thread;
}
@Override
public String toString()
{
return "RoundRobinScheduler.WeightedQueue(key=" + key + " weight=" + weight + ")";
}
private final static class Entry
{
public final long creationTime = System.nanoTime();
public final Thread thread;
public Entry(Thread thread)
{
this.thread = thread;
}
}
/** MBean related methods */
public long getOperations()
{
return metric.latency.count();
}
public long getTotalLatencyMicros()
{
return metric.totalLatency.count();
}
public double getRecentLatencyMicros()
{
return metric.getRecentLatency();
}
public long[] getTotalLatencyHistogramMicros()
{
return metric.totalLatencyHistogram.getBuckets(false);
}
public long[] getRecentLatencyHistogramMicros()
{
return metric.recentLatencyHistogram.getBuckets(true);
}
}