/*
* Copyright (c) 2008-2017, Hazelcast, Inc. All Rights Reserved.
*
* 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 com.hazelcast.test.jitter;
import static com.hazelcast.test.jitter.JitterRule.RESOLUTION_NANOS;
import static java.lang.Math.min;
import static java.util.concurrent.locks.LockSupport.parkNanos;
public class JitterThread extends Thread {
private final JitterRecorder jitterRecorder;
public JitterThread(JitterRecorder jitterRecorder) {
this.jitterRecorder = jitterRecorder;
}
public void run() {
long beforeNanos = System.nanoTime();
long shortestHiccup = Long.MAX_VALUE;
for (; ; ) {
long beforeMillis = System.currentTimeMillis();
sleepNanos(RESOLUTION_NANOS);
long after = System.nanoTime();
long delta = after - beforeNanos;
long currentHiccup = delta - RESOLUTION_NANOS;
//subtract the shortest observed hiccups. as that's
//an inherit cost of the measuring loop and OS scheduler
//imprecision.
shortestHiccup = min(shortestHiccup, currentHiccup);
currentHiccup -= shortestHiccup;
jitterRecorder.recordPause(beforeMillis, currentHiccup);
beforeNanos = after;
}
}
private void sleepNanos(long duration) {
parkNanos(duration);
}
}