Merge pull request Kotlin#3035 from Kotlin/version-1.6.0-RC

Version 1.6.0-RC

CHANGES.md

@@ -1,5 +1,53 @@
 # Change log for kotlinx.coroutines
 
+## Version 1.6.0-RC
+
+### kotlinx-coroutines-test rework
+
+* `kotlinx-coroutines-test` became a multiplatform library usable from K/JVM, K/JS, and K/N.
+* Its API was completely reworked to address long-standing issues with consistency, structured concurrency and correctness (#1203, #1609, #2379, #1749, #1204, #1390, #1222, #1395, #1881, #1910, #1772, #1626, #1742, #2082, #2102, #2405, #2462
+ ).
+* The old API is deprecated for removal, but the new API is based on the similar concepts ([README](kotlinx-coroutines-test/README.md)), and the migration path is designed to be graceful: [migration guide](kotlinx-coroutines-test/MIGRATION.md)
+
+### Dispatchers
+
+* * Introduced `CoroutineDispatcher.limitedParallelism` that allows obtaining a view of the original dispatcher with limited parallelism (#2919).
+* `Dispatchers.IO.limitedParallelism` usages ignore the bound on the parallelism level of `Dispatchers.IO` itself to avoid starvation (#2943).
+* Introduced new `Dispatchers.shutdown` method for containerized environments (#2558).
+* `newSingleThreadContext` and `newFixedThreadPoolContext` are promoted to delicate API (#2919).
+
+### Breaking changes
+
+* When racing with cancellation, the `future` builder no longer reports unhandled exceptions into the global `CoroutineExceptionHandler`. Thanks @vadimsemenov! (#2774, #2791).
+* `Mutex.onLock` is deprecated for removal (#2794).
+* `Dispatchers.Main` is now used as the default source of time for `delay` and `withTimeout` when present(#2972).
+ * To opt-out from this behaviour, `kotlinx.coroutines.main.delay` system property can be set to `false`.
+* Java target of coroutines build is now 8 instead of 6 (#1589).
+
+### Bug fixes and improvements
+
+* Kotlin is updated to 1.6.0.
+* Kotlin/Native [new memory model](https://blog.jetbrains.com/kotlin/2021/08/try-the-new-kotlin-native-memory-manager-development-preview/) is now supported in regular builds of coroutines conditionally depending on whether `kotlin.native.binary.memoryModel` is enabled (#2914).
+* Introduced `CopyableThreadContextElement` for mutable context elements shared among multiple coroutines. Thanks @yorickhenning! (#2893).
+* `transformWhile`, `awaitClose`, `ProducerScope`, `merge`, `runningFold`, `runingReduce`, and `scan` are promoted to stable API (#2971).
+* `SharedFlow.subscriptionCount` no longer conflates incoming updates and gives all subscribers a chance to observe a short-lived subscription (#2488, #2863, #2871).
+* `Flow` exception transparency mechanism is improved to be more exception-friendly (#3017, #2860).
+* Cancellation from `flat*` operators that leverage multiple coroutines is no longer propagated upstream (#2964).
+* `SharedFlow.collect` now returns `Nothing` (#2789, #2502).
+* `FlowCollector` is now `fun interface`, and corresponding inline extension is removed (#2790).
+* Deprecation level of all previously deprecated signatures is raised (#3024).
+* The version file is shipped with each JAR as a resource (#2941).
+* Unhandled exceptions on K/N are passed to the standard library function `processUnhandledException` (#2981).
+* A direct executor is used for `Task` callbacks in `kotlinx-coroutines-play-services` (#2990).
+* Metadata of coroutines artifacts leverages Gradle platform to have all versions of dependencies aligned (#2865).
+* Default `CoroutineExceptionHandler` is loaded eagerly and does not invoke `ServiceLoader` on its exception-handling path (#2552).
+* Fixed the R8 rules for `ServiceLoader` optimization (#2880).
+* Fixed BlockHound integration false-positives (#2894, #2866, #2937).
+* The exception recovery mechanism now uses `ClassValue` when available (#2997).
+* JNA is updated to 5.9.0 to support Apple M1 (#3001).
+* Obsolete method on internal `Delay` interface is deprecated (#2979).
+* Support of deprecated `CommonPool` is removed.
+
 ## Version 1.5.2
 
 * Kotlin is updated to 1.5.30.

README.md

@@ -2,12 +2,12 @@
 
 [![official JetBrains project](https://jb.gg/badges/official.svg)](https://confluence.jetbrains.com/display/ALL/JetBrains+on+GitHub)
 [![GitHub license](https://img.shields.io/badge/license-Apache%20License%202.0-blue.svg?style=flat)](https://www.apache.org/licenses/LICENSE-2.0)
-[![Download](https://img.shields.io/maven-central/v/org.jetbrains.kotlinx/kotlinx-coroutines-core/1.5.2)](https://search.maven.org/artifact/org.jetbrains.kotlinx/kotlinx-coroutines-core/1.5.2/pom)
-[![Kotlin](https://img.shields.io/badge/kotlin-1.5.30-blue.svg?logo=kotlin)](http:https://kotlinlang.org)
+[![Download](https://img.shields.io/maven-central/v/org.jetbrains.kotlinx/kotlinx-coroutines-core/1.6.0-RC)](https://search.maven.org/artifact/org.jetbrains.kotlinx/kotlinx-coroutines-core/1.6.0-RC/pom)
+[![Kotlin](https://img.shields.io/badge/kotlin-1.6.0-blue.svg?logo=kotlin)](http:https://kotlinlang.org)
 [![Slack channel](https://img.shields.io/badge/chat-slack-green.svg?logo=slack)](https://kotlinlang.slack.com/messages/coroutines/)
 
 Library support for Kotlin coroutines with [multiplatform](#multiplatform) support.
-This is a companion version for the Kotlin `1.5.30` release.
+This is a companion version for the Kotlin `1.6.0` release.
 
 ```kotlin
 suspend fun main() = coroutineScope {
@@ -83,15 +83,15 @@ Add dependencies (you can also add other modules that you need):
 <dependency>
  <groupId>org.jetbrains.kotlinx</groupId>
  <artifactId>kotlinx-coroutines-core</artifactId>
- <version>1.5.2</version>
+ <version>1.6.0-RC</version>
 </dependency>
 ```
 
 And make sure that you use the latest Kotlin version:
 
 ```xml
 <properties>
- <kotlin.version>1.5.30</kotlin.version>
+ <kotlin.version>1.6.0</kotlin.version>
 </properties>
 ```
 
@@ -101,15 +101,15 @@ Add dependencies (you can also add other modules that you need):
 
 ```groovy
 dependencies {
- implementation 'org.jetbrains.kotlinx:kotlinx-coroutines-core:1.5.2'
+ implementation 'org.jetbrains.kotlinx:kotlinx-coroutines-core:1.6.0-RC'
 }
 ```
 
 And make sure that you use the latest Kotlin version:
 
 ```groovy
 buildscript {
- ext.kotlin_version = '1.5.30'
+ ext.kotlin_version = '1.6.0'
 }
 ```
 
@@ -127,7 +127,7 @@ Add dependencies (you can also add other modules that you need):
 
 ```groovy
 dependencies {
- implementation("org.jetbrains.kotlinx:kotlinx-coroutines-core:1.5.2")
+ implementation("org.jetbrains.kotlinx:kotlinx-coroutines-core:1.6.0-RC")
 }
 ```
 
@@ -147,7 +147,7 @@ Add [`kotlinx-coroutines-android`](ui/kotlinx-coroutines-android)
 module as a dependency when using `kotlinx.coroutines` on Android:
 
 ```groovy
-implementation 'org.jetbrains.kotlinx:kotlinx-coroutines-android:1.5.2'
+implementation 'org.jetbrains.kotlinx:kotlinx-coroutines-android:1.6.0-RC'
 ```
 
 This gives you access to the Android [Dispatchers.Main]
@@ -180,7 +180,7 @@ In common code that should get compiled for different platforms, you can add a d
 ```groovy
 commonMain {
  dependencies {
- implementation("org.jetbrains.kotlinx:kotlinx-coroutines-core:1.5.2")
+ implementation("org.jetbrains.kotlinx:kotlinx-coroutines-core:1.6.0-RC")
  }
 }
 ```
@@ -192,7 +192,7 @@ Platform-specific dependencies are recommended to be used only for non-multiplat
 #### JS
 
 Kotlin/JS version of `kotlinx.coroutines` is published as 
-[`kotlinx-coroutines-core-js`](https://search.maven.org/artifact/org.jetbrains.kotlinx/kotlinx-coroutines-core-js/1.5.2/jar)
+[`kotlinx-coroutines-core-js`](https://search.maven.org/artifact/org.jetbrains.kotlinx/kotlinx-coroutines-core-js/1.6.0-RC/jar)
 (follow the link to get the dependency declaration snippet) and as [`kotlinx-coroutines-core`](https://www.npmjs.com/package/kotlinx-coroutines-core) NPM package. 
 
 #### Native

benchmarks/build.gradle.kts

@@ -46,21 +46,28 @@ extensions.configure<JMHPluginExtension>("jmh") {
 // includeTests = false
 }
 
-tasks.named<Jar>("jmhJar") {
+val jmhJarTask = tasks.named<Jar>("jmhJar") {
  archiveBaseName by "benchmarks"
  archiveClassifier by null
  archiveVersion by null
  destinationDirectory.file("$rootDir")
 }
 
+tasks {
+ build {
+ dependsOn(jmhJarTask)
+ }
+}
+
 dependencies {
- compile("org.openjdk.jmh:jmh-core:1.26")
- compile("io.projectreactor:reactor-core:${version("reactor")}")
- compile("io.reactivex.rxjava2:rxjava:2.1.9")
- compile("com.github.akarnokd:rxjava2-extensions:0.20.8")
+ implementation("org.openjdk.jmh:jmh-core:1.26")
+ implementation("io.projectreactor:reactor-core:${version("reactor")}")
+ implementation("io.reactivex.rxjava2:rxjava:2.1.9")
+ implementation("com.github.akarnokd:rxjava2-extensions:0.20.8")
 
- compile("com.typesafe.akka:akka-actor_2.12:2.5.0")
- compile(project(":kotlinx-coroutines-core"))
+ implementation("com.typesafe.akka:akka-actor_2.12:2.5.0")
+ implementation(project(":kotlinx-coroutines-core"))
+ implementation(project(":kotlinx-coroutines-reactive"))
 
  // add jmh dependency on main
  "jmhImplementation"(sourceSets.main.get().runtimeClasspath)

benchmarks/src/jmh/kotlin/benchmarks/ParametrizedDispatcherBase.kt

@@ -30,7 +30,7 @@ abstract class ParametrizedDispatcherBase : CoroutineScope {
  coroutineContext = when {
  dispatcher == "fjp" -> ForkJoinPool.commonPool().asCoroutineDispatcher()
  dispatcher == "scheduler" -> {
- ExperimentalCoroutineDispatcher(CORES_COUNT).also { closeable = it }
+ Dispatchers.Default
  }
  dispatcher.startsWith("ftp") -> {
  newFixedThreadPoolContext(dispatcher.substring(4).toInt(), dispatcher).also { closeable = it }

benchmarks/src/jmh/kotlin/benchmarks/SemaphoreBenchmark.kt

@@ -6,13 +6,10 @@ package benchmarks
 
 import benchmarks.common.*
 import kotlinx.coroutines.*
-import kotlinx.coroutines.channels.Channel
-import kotlinx.coroutines.scheduling.ExperimentalCoroutineDispatcher
-import kotlinx.coroutines.sync.Semaphore
-import kotlinx.coroutines.sync.withPermit
+import kotlinx.coroutines.channels.*
+import kotlinx.coroutines.sync.*
 import org.openjdk.jmh.annotations.*
-import java.util.concurrent.ForkJoinPool
-import java.util.concurrent.TimeUnit
+import java.util.concurrent.*
 
 @Warmup(iterations = 3, time = 500, timeUnit = TimeUnit.MICROSECONDS)
 @Measurement(iterations = 10, time = 500, timeUnit = TimeUnit.MICROSECONDS)
@@ -84,7 +81,7 @@ open class SemaphoreBenchmark {
 
 enum class SemaphoreBenchDispatcherCreator(val create: (parallelism: Int) -> CoroutineDispatcher) {
  FORK_JOIN({ parallelism -> ForkJoinPool(parallelism).asCoroutineDispatcher() }),
- EXPERIMENTAL({ parallelism -> ExperimentalCoroutineDispatcher(corePoolSize = parallelism, maxPoolSize = parallelism) })
+ EXPERIMENTAL({ parallelism -> Dispatchers.Default }) // TODO doesn't take parallelism into account
 }
 
 private const val WORK_INSIDE = 80

benchmarks/src/jmh/kotlin/benchmarks/flow/scrabble/SequencePlaysScrabble.kt

@@ -30,7 +30,7 @@ open class SequencePlaysScrabble : ShakespearePlaysScrabble() {
  val bonusForDoubleLetter: (String) -> Int = { word: String ->
  toBeMaxed(word)
  .map { letterScores[it - 'a'.toInt()] }
- .max()!!
+ .maxOrNull()!!
  }
 
  val score3: (String) -> Int = { word: String ->

benchmarks/src/jmh/kotlin/benchmarks/scheduler/actors/PingPongWithBlockingContext.kt

@@ -27,10 +27,8 @@ import kotlin.coroutines.*
 @State(Scope.Benchmark)
 open class PingPongWithBlockingContext {
 
- @UseExperimental(InternalCoroutinesApi::class)
- private val experimental = ExperimentalCoroutineDispatcher(8)
- @UseExperimental(InternalCoroutinesApi::class)
- private val blocking = experimental.blocking(8)
+ private val experimental = Dispatchers.Default
+ private val blocking = Dispatchers.IO.limitedParallelism(8)
  private val threadPool = newFixedThreadPoolContext(8, "PongCtx")
 
  @TearDown