Version 1.6.0

CHANGES.md

@@ -1,5 +1,66 @@
 # Change log for kotlinx.coroutines
 
+## Version 1.6.0
+
+Note that this is a full changelog relative to 1.5.2 version. Changelog relative to 1.6.0-RC3 can be found in the end.
+
+### 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).
+* `DisposableHandle` is now `fun interface`, and corresponding inline extension is removed (#2790).
+* `FlowCollector` is now `fun interface`, and corresponding inline extension is removed (#3047).
+* 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).
+* Fixed the exception handler being invoked several times on Android, thanks to @1zaman (#3056).
+* `SendChannel.trySendBlocking` is now available on Kotlin/Native (#3064).
+* 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.
+* `@ExperimentalTime` is no longer needed for methods that use `Duration` (#3041).
+* JDK 1.6 is no longer required for building the project (#3043).
+* New version of Dokka is used, fixing the memory leak when building the coroutines and providing brand new reference visuals (https://kotlin.github.io/kotlinx.coroutines/) (#3051, #3054).
+
+### Changelog relative to version 1.6.0-RC3
+
+* Restored MPP binary compatibility on K/JS and K/N (#3104).
+* Fixed Dispatchers.Main not being fully initialized on Android and Swing (#3101).
+
 ## Version 1.6.0-RC3
 
 * Fixed the error in 1.6.0-RC2 because of which `Flow.collect` couldn't be called due to the `@InternalCoroutinesApi` annotation (#3082)
@@ -29,7 +90,7 @@
 
 ### Dispatchers
 
-* * Introduced `CoroutineDispatcher.limitedParallelism` that allows obtaining a view of the original dispatcher with limited parallelism (#2919).
+* 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).

README.md

@@ -2,7 +2,7 @@
 
 [![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/1.6.0-RC3)](https://search.maven.org/artifact/org.jetbrains.kotlinx/kotlinx-coroutines-core/1.6.0-RC3/pom)
+[![Download](https://img.shields.io/maven-central/v/org.jetbrains.kotlinx/kotlinx-coroutines-core/1.6.0)](https://search.maven.org/artifact/org.jetbrains.kotlinx/kotlinx-coroutines-core/1.6.0/pom)
 [![Kotlin](https://img.shields.io/badge/kotlin-1.6.0-blue.svg?logo=kotlin)](http://kotlinlang.org)
 [![Slack channel](https://img.shields.io/badge/chat-slack-green.svg?logo=slack)](https://kotlinlang.slack.com/messages/coroutines/)
 
@@ -83,7 +83,7 @@ Add dependencies (you can also add other modules that you need):
 <dependency>
     <groupId>org.jetbrains.kotlinx</groupId>
     <artifactId>kotlinx-coroutines-core</artifactId>
-    <version>1.6.0-RC3</version>
+    <version>1.6.0</version>
 </dependency>
 ```
 
@@ -101,7 +101,7 @@ Add dependencies (you can also add other modules that you need):
 
 ```groovy
 dependencies {
-    implementation 'org.jetbrains.kotlinx:kotlinx-coroutines-core:1.6.0-RC3'
+    implementation 'org.jetbrains.kotlinx:kotlinx-coroutines-core: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:1.6.0-RC3")
+    implementation("org.jetbrains.kotlinx:kotlinx-coroutines-core:1.6.0")
 }
 ```
 
@@ -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:1.6.0-RC3'
+implementation 'org.jetbrains.kotlinx:kotlinx-coroutines-android:1.6.0'
 ```
 
 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:1.6.0-RC3")
+        implementation("org.jetbrains.kotlinx:kotlinx-coroutines-core:1.6.0")
     }
 }
 ```
@@ -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/1.6.0-RC3/jar)
+[`kotlinx-coroutines-core-js`](https://search.maven.org/artifact/org.jetbrains.kotlinx/kotlinx-coroutines-core-js/1.6.0/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

gradle.properties

@@ -3,7 +3,7 @@
 #
 
 # Kotlin
-version=1.6.0-RC3-SNAPSHOT
+version=1.6.0-SNAPSHOT
 group=org.jetbrains.kotlinx
 kotlin_version=1.6.0
 

kotlinx-coroutines-core/api/kotlinx-coroutines-core.api

@@ -919,6 +919,7 @@ public final class kotlinx/coroutines/flow/FlowKt {
 	public static final fun catch (Lkotlinx/coroutines/flow/Flow;Lkotlin/jvm/functions/Function3;)Lkotlinx/coroutines/flow/Flow;
 	public static final fun channelFlow (Lkotlin/jvm/functions/Function2;)Lkotlinx/coroutines/flow/Flow;
 	public static final fun collect (Lkotlinx/coroutines/flow/Flow;Lkotlin/coroutines/Continuation;)Ljava/lang/Object;
+	public static final synthetic fun collect (Lkotlinx/coroutines/flow/Flow;Lkotlin/jvm/functions/Function2;Lkotlin/coroutines/Continuation;)Ljava/lang/Object;
 	public static final fun collectIndexed (Lkotlinx/coroutines/flow/Flow;Lkotlin/jvm/functions/Function3;Lkotlin/coroutines/Continuation;)Ljava/lang/Object;
 	public static final fun collectLatest (Lkotlinx/coroutines/flow/Flow;Lkotlin/jvm/functions/Function2;Lkotlin/coroutines/Continuation;)Ljava/lang/Object;
 	public static final fun combine (Lkotlinx/coroutines/flow/Flow;Lkotlinx/coroutines/flow/Flow;Lkotlin/jvm/functions/Function3;)Lkotlinx/coroutines/flow/Flow;

kotlinx-coroutines-core/common/src/CoroutineDispatcher.kt

@@ -88,7 +88,8 @@ public abstract class CoroutineDispatcher :
      * // At most 1 thread will be doing IO
      * private val fileWriterDispatcher = backgroundDispatcher.limitedParallelism(1)
      * ```
-     * is 6. Yet at most 4 coroutines can be executed simultaneously as each view limits only its own parallelism.
+     * Note how in this example the application has an executor with 4 threads, but the total sum of all limits
+     * is 6. Still, at most 4 coroutines can be executed simultaneously as each view limits only its own parallelism.
      *
      * Note that this example was structured in such a way that it illustrates the parallelism guarantees.
      * In practice, it is usually better to use [Dispatchers.IO] or [Dispatchers.Default] instead of creating a

kotlinx-coroutines-core/common/src/flow/operators/Transform.kt

@@ -45,7 +45,7 @@ public fun <T: Any> Flow<T?>.filterNotNull(): Flow<T> = transform<T?, T> { value
  * Returns a flow containing the results of applying the given [transform] function to each value of the original flow.
  */
 public inline fun <T, R> Flow<T>.map(crossinline transform: suspend (value: T) -> R): Flow<R> = transform { value ->
-   return@transform emit(transform(value))
+    return@transform emit(transform(value))
 }
 
 /**

kotlinx-coroutines-core/common/src/flow/terminal/Collect.kt

@@ -108,3 +108,10 @@ public suspend fun <T> FlowCollector<T>.emitAll(flow: Flow<T>) {
     ensureActive()
     flow.collect(this)
 }
+
+/** @suppress */
+@Deprecated(level = DeprecationLevel.HIDDEN, message = "Backwards compatibility with JS and K/N")
+public suspend inline fun <T> Flow<T>.collect(crossinline action: suspend (value: T) -> Unit): Unit =
+    collect(object : FlowCollector<T> {
+        override suspend fun emit(value: T) = action(value)
+    })

kotlinx-coroutines-core/common/src/internal/MainDispatcherFactory.kt

@@ -14,6 +14,11 @@ public interface MainDispatcherFactory {
     /**
      * Creates the main dispatcher. [allFactories] parameter contains all factories found by service loader.
      * This method is not guaranteed to be idempotent.
+     *
+     * It is required that this method fails with an exception instead of returning an instance that doesn't work
+     * correctly as a [Delay].
+     * The reason for this is that, on the JVM, [DefaultDelay] will use [Dispatchers.Main] for most delays by default
+     * if this method returns an instance without throwing.
      */
     public fun createDispatcher(allFactories: List<MainDispatcherFactory>): MainCoroutineDispatcher
 

kotlinx-coroutines-debug/README.md

@@ -61,7 +61,7 @@ stacktraces will be dumped to the console.
 ### Using as JVM agent
 
 Debug module can also be used as a standalone JVM agent to enable debug probes on the application startup.
-You can run your application with an additional argument: `-javaagent:kotlinx-coroutines-debug-1.6.0-RC3.jar`.
+You can run your application with an additional argument: `-javaagent:kotlinx-coroutines-debug-1.6.0.jar`.
 Additionally, on Linux and Mac OS X you can use `kill -5 $pid` command in order to force your application to print all alive coroutines.
 When used as Java agent, `"kotlinx.coroutines.debug.enable.creation.stack.trace"` system property can be used to control 
 [DebugProbes.enableCreationStackTraces] along with agent startup.

kotlinx-coroutines-test/README.md

@@ -26,7 +26,7 @@ Provided [TestDispatcher] implementations:
 Add `kotlinx-coroutines-test` to your project test dependencies:
 ```
 dependencies {
-    testImplementation 'org.jetbrains.kotlinx:kotlinx-coroutines-test:1.6.0-RC3'
+    testImplementation 'org.jetbrains.kotlinx:kotlinx-coroutines-test:1.6.0'
 }
 ```
 

ui/coroutines-guide-ui.md

@@ -110,7 +110,7 @@ Add dependencies on `kotlinx-coroutines-android` module to the `dependencies { .
 `app/build.gradle` file:
 
 ```groovy
-implementation "org.jetbrains.kotlinx:kotlinx-coroutines-android:1.6.0-RC3"
+implementation "org.jetbrains.kotlinx:kotlinx-coroutines-android:1.6.0"
 ```
 
 You can clone [kotlinx.coroutines](https://github.com/Kotlin/kotlinx.coroutines) project from GitHub onto your 

ui/kotlinx-coroutines-android/src/HandlerDispatcher.kt

@@ -51,8 +51,10 @@ public sealed class HandlerDispatcher : MainCoroutineDispatcher(), Delay {
 
 internal class AndroidDispatcherFactory : MainDispatcherFactory {
 
-    override fun createDispatcher(allFactories: List<MainDispatcherFactory>) =
-        HandlerContext(Looper.getMainLooper().asHandler(async = true))
+    override fun createDispatcher(allFactories: List<MainDispatcherFactory>): MainCoroutineDispatcher {
+        val mainLooper = Looper.getMainLooper() ?: throw IllegalStateException("The main looper is not available")
+        return HandlerContext(mainLooper.asHandler(async = true))
+    }
 
     override fun hintOnError(): String = "For tests Dispatchers.setMain from kotlinx-coroutines-test module can be used"
 

ui/kotlinx-coroutines-swing/src/SwingDispatcher.kt

@@ -74,6 +74,16 @@ private object ImmediateSwingDispatcher : SwingDispatcher() {
  * Dispatches execution onto Swing event dispatching thread and provides native [delay] support.
  */
 internal object Swing : SwingDispatcher() {
+
+    /* A workaround so that the dispatcher's initialization crashes with an exception if running in a headless
+    environment. This is needed so that this broken dispatcher is not used as the source of delays. */
+    init {
+        Timer(1) { }.apply {
+            isRepeats = false
+            start()
+        }
+    }
+
     override val immediate: MainCoroutineDispatcher
         get() = ImmediateSwingDispatcher