fish.payara.microprofile.metrics.impl.Clock Maven / Gradle / Ivy
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package fish.payara.microprofile.metrics.impl;
import java.lang.management.ManagementFactory;
/**
* An abstraction for how time passes. It is passed to {@link Timer} to track
* timing.
*/
@FunctionalInterface
public interface Clock {
/**
* Returns the current time tick.
*
* @return time tick in nanoseconds
*/
long getTick();
/**
* Returns the current time in milliseconds.
*
* @return time in milliseconds
*/
default long getTime() {
return System.currentTimeMillis();
}
/**
* A clock implementation which returns the current time in epoch
* nanoseconds.
*/
Clock DEFAULT = () -> System.nanoTime();
/**
* The default clock to use.
*
* @return the {@link #DEFAULT} {@link Clock} instance
*/
public static Clock defaultClock() {
return DEFAULT;
}
/**
* A clock implementation which returns the current thread's CPU time.
*/
Clock THREAD_CPU_TIME = () -> ManagementFactory.getThreadMXBean().getCurrentThreadCpuTime();
}