edu.emory.mathcs.backport.java.util.concurrent

Class TimeUnit

public abstract class TimeUnit extends Object implements Serializable

A TimeUnit represents time durations at a given unit of granularity and provides utility methods to convert across units, and to perform timing and delay operations in these units. A TimeUnit does not maintain time information, but only helps organize and use time representations that may be maintained separately across various contexts. A nanosecond is defined as one thousandth of a microsecond, a microsecond as one thousandth of a millisecond, a millisecond as one thousandth of a second, a minute as sixty seconds, an hour as sixty minutes, and a day as twenty four hours.

A TimeUnit is mainly used to inform time-based methods how a given timing parameter should be interpreted. For example, the following code will timeout in 50 milliseconds if the lock is not available:

  Lock lock = ...;
  if ( lock.tryLock(50L, TimeUnit.MILLISECONDS) ) ...
 
while this code will timeout in 50 seconds:
  Lock lock = ...;
  if ( lock.tryLock(50L, TimeUnit.SECONDS) ) ...
 
Note however, that there is no guarantee that a particular timeout implementation will be able to notice the passage of time at the same granularity as the given TimeUnit.

Since: 1.5

Author: Doug Lea

Field Summary
static TimeUnitDAYS
static TimeUnitHOURS
static TimeUnitMICROSECONDS
static TimeUnitMILLISECONDS
static TimeUnitMINUTES
static TimeUnitNANOSECONDS
static TimeUnitSECONDS
Method Summary
abstract longconvert(long sourceDuration, TimeUnit sourceUnit)
Convert the given time duration in the given unit to this unit.
Stringname()
Returns the name of this enum constant, exactly as declared in its enum declaration.
intordinal()
Returns the ordinal of this enumeration constant (its position in its enum declaration, where the initial constant is assigned an ordinal of zero).
protected ObjectreadResolve()
voidsleep(long timeout)
Performs a Thread.sleep using this unit.
voidtimedJoin(Thread thread, long timeout)
Performs a timed Thread.join using this time unit.
voidtimedWait(Object obj, long timeout)
Performs a timed Object.wait using this time unit.
abstract longtoDays(long duration)
Equivalent to DAYS.convert(duration, this).
abstract longtoHours(long duration)
Equivalent to HOURS.convert(duration, this).
abstract longtoMicros(long duration)
Equivalent to MICROSECONDS.convert(duration, this).
abstract longtoMillis(long duration)
Equivalent to MILLISECONDS.convert(duration, this).
abstract longtoMinutes(long duration)
Equivalent to MINUTES.convert(duration, this).
abstract longtoNanos(long duration)
Equivalent to NANOSECONDS.convert(duration, this).
abstract longtoSeconds(long duration)
Equivalent to SECONDS.convert(duration, this).
StringtoString()
static TimeUnitvalueOf(String name)
Returns the enum constant of this type with the specified name.
static TimeUnit[]values()

Field Detail

DAYS

public static final TimeUnit DAYS

HOURS

public static final TimeUnit HOURS

MICROSECONDS

public static final TimeUnit MICROSECONDS

MILLISECONDS

public static final TimeUnit MILLISECONDS

MINUTES

public static final TimeUnit MINUTES

NANOSECONDS

public static final TimeUnit NANOSECONDS

SECONDS

public static final TimeUnit SECONDS

Method Detail

convert

public abstract long convert(long sourceDuration, TimeUnit sourceUnit)
Convert the given time duration in the given unit to this unit. Conversions from finer to coarser granularities truncate, so lose precision. For example converting 999 milliseconds to seconds results in 0. Conversions from coarser to finer granularities with arguments that would numerically overflow saturate to Long.MIN_VALUE if negative or Long.MAX_VALUE if positive.

For example, to convert 10 minutes to milliseconds, use: TimeUnit.MILLISECONDS.convert(10L, TimeUnit.MINUTES)

Parameters: sourceDuration the time duration in the given sourceUnit sourceUnit the unit of the sourceDuration argument

Returns: the converted duration in this unit, or Long.MIN_VALUE if conversion would negatively overflow, or Long.MAX_VALUE if it would positively overflow.

name

public String name()
Returns the name of this enum constant, exactly as declared in its enum declaration. Most programmers should use the toString method in preference to this one, as the toString method may return a more user-friendly name. This method is designed primarily for use in specialized situations where correctness depends on getting the exact name, which will not vary from release to release.

Returns: the name of this enum constant

ordinal

public int ordinal()
Returns the ordinal of this enumeration constant (its position in its enum declaration, where the initial constant is assigned an ordinal of zero). Most programmers will have no use for this method. It is designed for use by sophisticated enum-based data structures, such as EnumSet and EnumMap.

Returns: the ordinal of this enumeration constant

readResolve

protected Object readResolve()

sleep

public void sleep(long timeout)
Performs a Thread.sleep using this unit. This is a convenience method that converts time arguments into the form required by the Thread.sleep method.

Parameters: timeout the maximum time to sleep. If less than or equal to zero, do not sleep at all.

Throws: InterruptedException if interrupted while sleeping.

See Also: java.lang.Thread#sleep

timedJoin

public void timedJoin(Thread thread, long timeout)
Performs a timed Thread.join using this time unit. This is a convenience method that converts time arguments into the form required by the Thread.join method.

Parameters: thread the thread to wait for timeout the maximum time to wait. If less than or equal to zero, do not wait at all.

Throws: InterruptedException if interrupted while waiting.

See Also: java.lang.Thread#join(long, int)

timedWait

public void timedWait(Object obj, long timeout)
Performs a timed Object.wait using this time unit. This is a convenience method that converts timeout arguments into the form required by the Object.wait method.

For example, you could implement a blocking poll method (see BlockingQueue.poll) using:

  public synchronized  Object poll(long timeout, TimeUnit unit) throws InterruptedException {
    while (empty) {
      unit.timedWait(this, timeout);
      ...
    }
  }

Parameters: obj the object to wait on timeout the maximum time to wait. If less than or equal to zero, do not wait at all.

Throws: InterruptedException if interrupted while waiting.

See Also: java.lang.Object#wait(long, int)

toDays

public abstract long toDays(long duration)
Equivalent to DAYS.convert(duration, this).

Parameters: duration the duration

Returns: the converted duration

Since: 1.6

See Also: TimeUnit

toHours

public abstract long toHours(long duration)
Equivalent to HOURS.convert(duration, this).

Parameters: duration the duration

Returns: the converted duration, or Long.MIN_VALUE if conversion would negatively overflow, or Long.MAX_VALUE if it would positively overflow.

Since: 1.6

See Also: TimeUnit

toMicros

public abstract long toMicros(long duration)
Equivalent to MICROSECONDS.convert(duration, this).

Parameters: duration the duration

Returns: the converted duration, or Long.MIN_VALUE if conversion would negatively overflow, or Long.MAX_VALUE if it would positively overflow.

See Also: TimeUnit

toMillis

public abstract long toMillis(long duration)
Equivalent to MILLISECONDS.convert(duration, this).

Parameters: duration the duration

Returns: the converted duration, or Long.MIN_VALUE if conversion would negatively overflow, or Long.MAX_VALUE if it would positively overflow.

See Also: TimeUnit

toMinutes

public abstract long toMinutes(long duration)
Equivalent to MINUTES.convert(duration, this).

Parameters: duration the duration

Returns: the converted duration, or Long.MIN_VALUE if conversion would negatively overflow, or Long.MAX_VALUE if it would positively overflow.

Since: 1.6

See Also: TimeUnit

toNanos

public abstract long toNanos(long duration)
Equivalent to NANOSECONDS.convert(duration, this).

Parameters: duration the duration

Returns: the converted duration, or Long.MIN_VALUE if conversion would negatively overflow, or Long.MAX_VALUE if it would positively overflow.

See Also: TimeUnit

toSeconds

public abstract long toSeconds(long duration)
Equivalent to SECONDS.convert(duration, this).

Parameters: duration the duration

Returns: the converted duration, or Long.MIN_VALUE if conversion would negatively overflow, or Long.MAX_VALUE if it would positively overflow.

See Also: TimeUnit

toString

public String toString()

valueOf

public static TimeUnit valueOf(String name)
Returns the enum constant of this type with the specified name. The string must match exactly an identifier used to declare an enum constant in this type. (Extraneous whitespace characters are not permitted.)

Parameters: name the name of the enum constant to be returned

Returns: the enum constant with the specified name

Throws: IllegalArgumentException if this enum type has no constant with the specified name

values

public static TimeUnit[] values()