org.apache.hadoop.util

Class Time

java.lang.Object

org.apache.hadoop.util.Time

@InterfaceAudience.LimitedPrivate(value={"HDFS","MapReduce"})
@InterfaceStability.Unstable
public final class Time
extends Object

Utility methods for getting the time and computing intervals.

Constructor Summary

Constructors

Constructor and Description
Time()

Method Summary

Methods

Modifier and Type	Method and Description
static long	monotonicNow() Current time from some arbitrary time base in the past, counting in milliseconds, and not affected by settimeofday or similar system clock changes.
static long	now() Current system time.

Methods inherited from class java.lang.Object

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

Constructor Detail

Time

public Time()

Method Detail

now

public static long now()

Current system time. Do not use this to calculate a duration or interval to sleep, because it will be broken by settimeofday. Instead, use monotonicNow.

Returns:

current time in msec.

monotonicNow

public static long monotonicNow()

Current time from some arbitrary time base in the past, counting in milliseconds, and not affected by settimeofday or similar system clock changes. This is appropriate to use when computing how much longer to wait for an interval to expire.

Returns:

a monotonic clock that counts in milliseconds.