/Scala 2.12 Library

Package scala.concurrent.duration

package duration

Linear Supertypes

Type Members

case class Deadline extends Ordered[Deadline] with Product with Serializable

This class stores a deadline, as obtained via Deadline.now or the duration DSL:

import scala.concurrent.duration._

Its main purpose is to manage repeated attempts to achieve something (like awaiting a condition) by offering the methods hasTimeLeft and timeLeft. All durations are measured according to System.nanoTime aka wall-time; this does not take into account changes to the system clock (such as leap seconds).

implicit final class DoubleMult extends AnyVal

sealed abstract class Duration extends Serializable with Ordered[Duration]

Utility for working with java.util.concurrent.TimeUnit durations.

This class is not meant as a general purpose representation of time, it is optimized for the needs of scala.concurrent.

Basic Usage


import scala.concurrent.duration._

val duration = Duration(100, MILLISECONDS)
val duration = Duration(100, "millis")

duration < 1.second
duration <= Duration.Inf

Invoking inexpressible conversions (like calling toSeconds on an infinite duration) will throw an IllegalArgumentException.

Implicits are also provided for Int, Long and Double. Example usage:

import scala.concurrent.duration._

val duration = 100 millis

The DSL provided by the implicit conversions always allows construction of finite durations, even for infinite Double inputs; use Duration.Inf instead.

Extractors, parsing and arithmetic are also included:

val d = Duration("1.2 µs")
val Duration(length, unit) = 5 millis
val d2 = d * 2.5
val d3 = d2 + 1.millisecond

Handling of Time Units

Calculations performed on finite durations always retain the more precise unit of either operand, no matter whether a coarser unit would be able to exactly express the same duration. This means that Duration can be used as a lossless container for a (length, unit) pair if it is constructed using the corresponding methods and no arithmetic is performed on it; adding/subtracting durations should in that case be done with care.

Correspondence to Double Semantics

The semantics of arithmetic operations on Duration are two-fold:

    exact addition/subtraction with nanosecond resolution for finite durations, independent of the summands' magnitudeisomorphic to java.lang.Double when it comes to infinite or undefined values

The conversion between Duration and Double is done using Duration.toUnit (with unit NANOSECONDS) and Duration.fromNanos(Double)


The default ordering is consistent with the ordering of Double numbers, which means that Undefined is considered greater than all other durations, including Duration.Inf.

trait DurationConversions extends Any

implicit final class DurationDouble extends AnyVal with DurationConversions

implicit final class DurationInt extends AnyVal with DurationConversions

implicit final class DurationLong extends AnyVal with DurationConversions

final class FiniteDuration extends Duration

This class represents a finite duration. Its addition and subtraction operators are overloaded to retain this guarantee statically. The range of this class is limited to +-(2^63-1)ns, which is roughly 292 years.

implicit final class IntMult extends AnyVal

implicit final class LongMult extends AnyVal

type TimeUnit = java.util.concurrent.TimeUnit

Value Members

final val DAYS: java.util.concurrent.TimeUnit(DAYS)

final val HOURS: java.util.concurrent.TimeUnit(HOURS)

final val MICROSECONDS: java.util.concurrent.TimeUnit(MICROSECONDS)

final val MILLISECONDS: java.util.concurrent.TimeUnit(MILLISECONDS)

final val MINUTES: java.util.concurrent.TimeUnit(MINUTES)

final val NANOSECONDS: java.util.concurrent.TimeUnit(NANOSECONDS)

final val SECONDS: java.util.concurrent.TimeUnit(SECONDS)

implicit def durationToPair(d: Duration): (Long, TimeUnit)

implicit def pairIntToDuration(p: (Int, TimeUnit)): Duration

implicit def pairLongToDuration(p: (Long, TimeUnit)): FiniteDuration

object Deadline extends Serializable

object Duration extends Serializable

object DurationConversions

object FiniteDuration extends Serializable

object fromNow

This object can be used as closing token for declaring a deadline at some future point in time:

import scala.concurrent.duration._

val deadline = 3 seconds fromNow

object span

This object can be used as closing token if you prefer dot-less style but do not want to enable language.postfixOps:

import scala.concurrent.duration._

val duration = 2 seconds span

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Licensed under the Apache License, Version 2.0.