/*
* 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 io.airlift.stats;
import com.google.common.annotations.Beta;
import io.airlift.units.Duration;
import java.lang.management.ManagementFactory;
import java.lang.management.ThreadMXBean;
import static com.google.common.base.MoreObjects.toStringHelper;
import static java.util.concurrent.TimeUnit.NANOSECONDS;
@Beta
public class CpuTimer
{
private static final ThreadMXBean THREAD_MX_BEAN = ManagementFactory.getThreadMXBean();
private final long wallStartTime;
private final long cpuStartTime;
private final long userStartTime;
private long intervalWallStart;
private long intervalCpuStart;
private long intervalUserStart;
public CpuTimer()
{
wallStartTime = System.nanoTime();
cpuStartTime = THREAD_MX_BEAN.getCurrentThreadCpuTime();
userStartTime = THREAD_MX_BEAN.getCurrentThreadUserTime();
intervalWallStart = wallStartTime;
intervalCpuStart = cpuStartTime;
intervalUserStart = userStartTime;
}
public CpuDuration startNewInterval()
{
long currentWallTime = System.nanoTime();
long currentCpuTime = THREAD_MX_BEAN.getCurrentThreadCpuTime();
long currentUserTime = THREAD_MX_BEAN.getCurrentThreadUserTime();
CpuDuration cpuDuration = new CpuDuration(
nanosBetween(intervalWallStart, currentWallTime),
nanosBetween(intervalCpuStart, currentCpuTime),
nanosBetween(intervalUserStart, currentUserTime));
intervalWallStart = currentWallTime;
intervalCpuStart = currentCpuTime;
intervalUserStart = currentUserTime;
return cpuDuration;
}
public CpuDuration elapsedIntervalTime()
{
long currentWallTime = System.nanoTime();
long currentCpuTime = THREAD_MX_BEAN.getCurrentThreadCpuTime();
long currentUserTime = THREAD_MX_BEAN.getCurrentThreadUserTime();
return new CpuDuration(
nanosBetween(intervalWallStart, currentWallTime),
nanosBetween(intervalCpuStart, currentCpuTime),
nanosBetween(intervalUserStart, currentUserTime));
}
public CpuDuration elapsedTime()
{
long currentWallTime = System.nanoTime();
long currentCpuTime = THREAD_MX_BEAN.getCurrentThreadCpuTime();
long currentUserTime = THREAD_MX_BEAN.getCurrentThreadUserTime();
return new CpuDuration(
nanosBetween(wallStartTime, currentWallTime),
nanosBetween(cpuStartTime, currentCpuTime),
nanosBetween(userStartTime, currentUserTime));
}
private static Duration nanosBetween(long start, long end)
{
return new Duration(Math.abs(end - start), NANOSECONDS);
}
public static class CpuDuration
{
private final Duration wall;
private final Duration cpu;
private final Duration user;
public CpuDuration()
{
this.wall = new Duration(0, NANOSECONDS);
this.cpu = new Duration(0, NANOSECONDS);
this.user = new Duration(0, NANOSECONDS);
}
public CpuDuration(Duration wall, Duration cpu, Duration user)
{
this.wall = wall;
this.cpu = cpu;
this.user = user;
}
public Duration getWall()
{
return wall;
}
public Duration getCpu()
{
return cpu;
}
public Duration getUser()
{
return user;
}
public CpuDuration add(CpuDuration cpuDuration)
{
return new CpuDuration(
addDurations(wall, cpuDuration.wall),
addDurations(cpu, cpuDuration.cpu),
addDurations(user, cpuDuration.user));
}
public CpuDuration subtract(CpuDuration cpuDuration)
{
return new CpuDuration(
subtractDurations(wall, cpuDuration.wall),
subtractDurations(cpu, cpuDuration.cpu),
subtractDurations(user, cpuDuration.user));
}
private static Duration addDurations(Duration a, Duration b)
{
return new Duration(a.getValue(NANOSECONDS) + b.getValue(NANOSECONDS), NANOSECONDS);
}
private static Duration subtractDurations(Duration a, Duration b)
{
return new Duration(Math.max(0, a.getValue(NANOSECONDS) - b.getValue(NANOSECONDS)), NANOSECONDS);
}
@Override
public String toString()
{
return toStringHelper(this)
.add("wall", wall)
.add("cpu", cpu)
.add("user", user)
.toString();
}
}
}