kotlinx.coroutines

Library support for Kotlin coroutines. This is a companion version for Kotlin 1.1.0-beta-22 release.

Modules and features

• kotlinx-coroutines-core module with core primitives to work with coroutines. It is designed to work on any JDK6+ and Android and contains the following main pieces:

  • launch(context) {...} to start a coroutine in the given context and get reference to its Job.
  • run(context) {...} to switch to a different context inside a coroutine.
  • runBlocking {...} to use asynchronous Kotlin APIs from a thread-blocking code.
  • defer(context) {...} and lazyDefer(context) {...} to get a deferred result of coroutine execution in a non-blocking way via a light-weight future interface called Deferred.
  • delay(...) for a non-blocking sleep in coroutines and yield to release a thread in single-threaded dispatchers.
  • withTimeout(timeout) {...} scope function to easily set coroutine time-limit (deadline), and NonCancellable context to avoid it when needed.
  • CommonPool and Here contexts, access to context of a parent coroutine in its CoroutineScope.
  • newSingleThreadContext(...) and newFixedThreadPoolContext(...) functions, Executor.toCoroutineDispatcher() extension.
  • Cancellation support with Job interface and suspendCancellableCoroutine helper function.
  • Debugging facilities for coroutines (run JVM with -ea or -Dkotlinx.coroutines.debug options) and newCoroutineContext(context) function to write user-defined coroutine builders that work with these debugging facilities.

• kotlinx-coroutines-jdk8 module with additional libraries for JDK8 (or Android API level 24).

  • future { ... } coroutine builder that returns CompletableFuture and works in CommonPool context by default.
  • .await() suspending function for CompletableFuture.

• kotlinx-coroutines-nio module with extensions for asynchronous IO on JDK7+.

• kotlinx-coroutines-swing module with Swing context for Swing UI applications.

• kotlinx-coroutines-javafx module with JavaFx context for JavaFX UI applications.

• kotlinx-coroutines-rx module with utilities to build Observable objects from RxJava with imperative coroutines and consume their values from inside coroutines. It is in very basic form now (example-only, not even close to production use)

References and documentation

• Guide to kotlinx.coroutines by example
• Change log for kotlinx.coroutines
• Coroutines design document (KEEP)

Using in your projects

Note that these libraries are experimental and are subject to change.

The libraries are published to kotlin-eap-1.1 bintray repository.

These libraries require kotlin compiler version to be at least 1.1-Beta and require kotlin runtime of the same version as a dependency, which can be obtained from the same repository.

Maven

Add the bintray repository to <repositories> section (and also add pluginRepository to <pluginRepositories>, if you're willing to get kotlin-maven-plugin from there):

<repository>
    <snapshots>
        <enabled>false</enabled>
    </snapshots>
    <id>dl</id>
    <name>bintray</name>
    <url>http://dl.bintray.com/kotlin/kotlin-eap-1.1</url>
</repository>

Add dependencies (you can also add other modules that you need):

<dependency>
    <groupId>org.jetbrains.kotlinx</groupId>
    <artifactId>kotlinx-coroutines-core</artifactId>
    <version>0.5-beta</version>
</dependency>

And make sure that you use the right Kotlin version:

<properties>
    <kotlin.version>1.1.0-beta-22</kotlin.version>
</properties>

Gradle

Add the bintray repository (and also add it to buildScript section, if you're willing to get kotlin-gradle-plugin from there):

repositories {
    maven {
        url "http://dl.bintray.com/kotlin/kotlin-eap-1.1"
    }
}

Add dependencies (you can also add other modules that you need):

compile 'org.jetbrains.kotlinx:kotlinx-coroutines-core:0.5-beta'

And make sure that you use the right Kotlin version:

buildscript {
    ext.kotlin_version = '1.1.0-beta-22'
}