Package org.apache.flink.util.clock

Class 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 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