org.apache.flink.util.clock

Class Clock

java.lang.Object

org.apache.flink.util.clock.Clock

All Implemented Interfaces:

RelativeClock

Direct Known Subclasses:

ManualClock, SystemClock

@PublicEvolving
public abstract class Clock
extends Object
implements RelativeClock

A clock that gives access to time. This clock returns two flavors of time:

Absolute Time

This refers to real world wall clock time, and it is typically derived from a system clock. It is subject to clock drift and inaccuracy, and can jump if the system clock is adjusted. Absolute time behaves similar to System.currentTimeMillis().

Relative Time

This time advances at the same speed as the absolute time, but the timestamps can only be referred to relative to each other. The timestamps have no absolute meaning and cannot be compared across JVM processes. The source for the timestamps is not affected by adjustments to the system clock, so it never jumps. Relative time behaves similar to System.nanoTime().

Constructor Summary

Constructors

Constructor and Description
Clock()

Method Summary

Modifier and Type	Method and Description
abstract long	absoluteTimeMillis() Gets the current absolute time, in milliseconds.
abstract long	relativeTimeMillis() Gets the current relative time, in milliseconds.
abstract long	relativeTimeNanos() Gets the current relative time, in nanoseconds.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

Clock

public Clock()

Method Detail

absoluteTimeMillis

public abstract long absoluteTimeMillis()

Gets the current absolute time, in milliseconds.

relativeTimeMillis

public abstract long relativeTimeMillis()

Gets the current relative time, in milliseconds.

Specified by:

relativeTimeMillis in interface RelativeClock

relativeTimeNanos

public abstract long relativeTimeNanos()

Gets the current relative time, in nanoseconds.

Specified by:

relativeTimeNanos in interface RelativeClock