/*
* Copyright 2013-present Facebook, Inc.
*
* 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.facebook.buck.timing;
import java.lang.management.ManagementFactory;
import java.lang.management.ThreadMXBean;
/** {@link Clock} implementation that invokes the {@link System} calls. */
public class DefaultClock implements Clock {
private final ThreadMXBean threadMXBean;
private final boolean userNanoTimeEnabled;
public DefaultClock() {
this(true);
}
public DefaultClock(boolean enableThreadCpuTime) {
threadMXBean = ManagementFactory.getThreadMXBean();
userNanoTimeEnabled = enableThreadCpuTime && threadMXBean.isThreadCpuTimeEnabled();
}
@Override
public long currentTimeMillis() {
return System.currentTimeMillis();
}
@Override
public long nanoTime() {
return System.nanoTime();
}
@Override
public long threadUserNanoTime(long threadId) {
if (!userNanoTimeEnabled) {
return -1;
}
return threadMXBean.getThreadUserTime(threadId);
}
}