Merge pull request #2675 from Kotlin/version-1.5.0-rc

Version 1.5.0-RC

CHANGES.md

@@ -1,5 +1,37 @@
 # Change log for kotlinx.coroutines
 
+## Version 1.5.0-RC
+
+### Channels API
+
+* Major channels API rework (#330, #974). Existing `offer`, `poll`, and `sendBlocking` methods are deprecated, internal `receiveCatching` and `onReceiveCatching` removed, `receiveOrNull` and `onReceiveOrNull` are completely deprecated. Previously deprecated `SendChannel.isFull` declaration is removed. Channel operators deprecated with `ERROR` are now `HIDDEN`.
+* New methods `receiveCatching`, `onReceiveCatching` `trySend`, `tryReceive`, and `trySendBlocking` along with the new result type `ChannelResult` are introduced. They provide better type safety, are less error-prone, and have a consistent future-proof naming scheme.  The full rationale behind this change can be found [here](https://github.com/Kotlin/kotlinx.coroutines/issues/974#issuecomment-806569582).
+* `BroadcastChannel` and `ConflatedBroadcastChannel` are marked as `ObsoleteCoroutinesApi` in the favor or `SharedFlow` and `StateFlow`. The migration scheme can be found in their documentation. These classes will be deprecated in the next major release.
+* `callbackFlow` and `channelFlow` are promoted to stable API.
+
+### Reactive integrations
+
+* All existing API in modules `kotlinx-coroutines-rx2`, `kotlinx-coroutines-rx3`, `kotlinx-coroutines-reactive`, `kotlinx-coroutines-reactor`, and `kotlinx-coroutines-jdk9` were revisited and promoted to stable (#2545).
+* `publish` is no longer allowed to emit `null` values (#2646).
+* Misleading `awaitSingleOr*` functions on `Publisher` type are deprecated (#2591).
+* `MaybeSource.await` is deprecated in the favor of `awaitSingle`, additional lint functions for `Mono` are added in order to prevent ambiguous `Publisher` usages (#2628, #1587).
+* `ContextView` support in `kotlinx-coroutines-reactor` (#2575).
+* All reactive builders no longer ignore inner cancellation exceptions preventing their completion (#2262, #2646).
+* `MaybeSource.collect` and `Maybe.collect` properly finish when they are completed without a value (#2617).
+* All exceptions are now consistently handled according to reactive specification, whether they are considered 'fatal' or not by reactive frameworks (#2646).
+
+### Other improvements
+
+* `Flow.last` and `Flow.lastOrNull` operators (#2246).
+* `Flow.runningFold` operator (#2641).
+* `CoroutinesTimeout` rule for JUnit5 (#2197).
+* Internals of `Job` and `AbstractCoroutine` was reworked, resulting in smaller code size, less memory footprint, and better performance (#2513, #2512).
+* `CancellationException` from Kotlin standard library is used for cancellation on Koltin/JS and Kotlin/Native (#2638).
+* Introduced new `DelicateCoroutineApi` annotation that warns users about potential target API pitfalls and suggests studying API's documentation first. The only delicate API right now is `GlobalScope` (#2637).
+* Fixed bug introduced in `1.4.3` when `kotlinx-coroutines-core.jar` triggered IDEA debugger failure (#2619).
+* Fixed memory leak of `ChildHandlerNode` with reusable continuations (#2564).
+* Various documentation improvements (#2555, #2589, #2592, #2583, #2437, #2616, #2633, #2560).
+
 ## Version 1.4.3 
 
 ### General changes

CONTRIBUTING.md

@@ -52,15 +52,17 @@ so do familiarize yourself with the following guidelines.
   * Follow the style of writing tests that is used in this project: 
     name test functions as `testXxx`. Don't use backticks in test names.
 * If you introduce any new public APIs:
+  * Comment on the existing issue if you want to work on it or create one beforehand. 
+    Ensure that the issue not only describes a problem, but also describes a solution that had received a positive feedback. Propose a solution if there isn't any.
+    PRs with new API, but without a corresponding issue with a positive feedback about the proposed implementation are unlikely to
+    be approved or reviewed.
   * All new APIs must come with documentation and tests.
   * All new APIs are initially released with `@ExperimentalCoroutineApi` annotation and are graduated later.
   * [Update the public API dumps](#updating-the-public-api-dump) and commit the resulting changes as well. 
     It will not pass the tests otherwise.
   * If you plan large API additions, then please start by submitting an issue with the proposed API design  
     to gather community feedback.
   * [Contact the maintainers](#contacting-maintainers) to coordinate any big piece of work in advance.
-* Comment on the existing issue if you want to work on it. Ensure that the issue not only describes a problem,
-  but also describes a solution that had received a positive feedback. Propose a solution if there isn't any.
 * Steps for contributing new integration modules are explained [here](integration/README.md#Contributing).
 
 ## Building

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/1.4.3)](https://search.maven.org/artifact/org.jetbrains.kotlinx/kotlinx-coroutines-core/1.4.3/pom)
-[![Kotlin](https://img.shields.io/badge/kotlin-1.4.30-blue.svg?logo=kotlin)](http://kotlinlang.org)
+[![Download](https://img.shields.io/maven-central/v/org.jetbrains.kotlinx/kotlinx-coroutines-core/1.5.0-RC)](https://search.maven.org/artifact/org.jetbrains.kotlinx/kotlinx-coroutines-core/1.5.0-RC/pom)
+[![Kotlin](https://img.shields.io/badge/kotlin-1.5.0-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/)
 
 Library support for Kotlin coroutines with [multiplatform](#multiplatform) support.
-This is a companion version for the Kotlin `1.4.30` release.
+This is a companion version for the Kotlin `1.5.0` release.
 
 ```kotlin
 suspend fun main() = coroutineScope {
@@ -75,10 +75,6 @@ suspend fun main() = coroutineScope {
 
 ## Using in your projects
 
-The libraries are published to [kotlinx](https://bintray.com/kotlin/kotlinx/kotlinx.coroutines) Bintray repository,
-linked to [JCenter](https://bintray.com/bintray/jcenter?filterByPkgName=kotlinx.coroutines) and 
-pushed to [Maven Central](https://search.maven.org/#search%7Cga%7C1%7Cg%3Aorg.jetbrains.kotlinx%20a%3Akotlinx-coroutines*).
-
 ### Maven
 
 Add dependencies (you can also add other modules that you need):
@@ -87,15 +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>1.4.3</version>
+    <version>1.5.0-RC</version>
 </dependency>
 ```
 
 And make sure that you use the latest Kotlin version:
 
 ```xml
 <properties>
-    <kotlin.version>1.4.30</kotlin.version>
+    <kotlin.version>1.5.0</kotlin.version>
 </properties>
 ```
 
@@ -105,15 +101,15 @@ Add dependencies (you can also add other modules that you need):
 
 ```groovy
 dependencies {
-    implementation 'org.jetbrains.kotlinx:kotlinx-coroutines-core:1.4.3'
+    implementation 'org.jetbrains.kotlinx:kotlinx-coroutines-core:1.5.0-RC'
 }
 ```
 
 And make sure that you use the latest Kotlin version:
 
 ```groovy
 buildscript {
-    ext.kotlin_version = '1.4.30'
+    ext.kotlin_version = '1.5.0'
 }
 ```
 
@@ -131,15 +127,15 @@ Add dependencies (you can also add other modules that you need):
 
 ```groovy
 dependencies {
-    implementation("org.jetbrains.kotlinx:kotlinx-coroutines-core:1.4.3")
+    implementation("org.jetbrains.kotlinx:kotlinx-coroutines-core:1.5.0-RC")
 }
 ```
 
 And make sure that you use the latest Kotlin version:
 
 ```groovy
 plugins {
-    kotlin("jvm") version "1.4.30"
+    kotlin("jvm") version "1.5.0"
 }
 ```
 
@@ -151,7 +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:1.4.3'
+implementation 'org.jetbrains.kotlinx:kotlinx-coroutines-android:1.5.0-RC'
 ```
 
 This gives you access to the Android [Dispatchers.Main]
@@ -184,7 +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:1.4.3")
+        implementation("org.jetbrains.kotlinx:kotlinx-coroutines-core:1.5.0-RC")
     }
 }
 ```
@@ -196,7 +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/1.4.3/jar)
+[`kotlinx-coroutines-core-js`](https://search.maven.org/artifact/org.jetbrains.kotlinx/kotlinx-coroutines-core-js/1.5.0-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

build.gradle

@@ -53,18 +53,11 @@ buildscript {
     }
 
     repositories {
-        maven {url "https://kotlin.bintray.com/kotlinx"}
-        // Future replacement for kotlin-dev, with cache redirector
-        maven { url "https://cache-redirector.jetbrains.com/maven.pkg.jetbrains.space/kotlin/p/kotlin/dev" }
-        maven {
-            url "https://kotlin.bintray.com/kotlin-dev"
-            credentials {
-                username = project.hasProperty('bintrayUser') ? project.property('bintrayUser') : System.getenv('BINTRAY_USER') ?: ""
-                password = project.hasProperty('bintrayApiKey') ? project.property('bintrayApiKey') : System.getenv('BINTRAY_API_KEY') ?: ""
-            }
-        }
+        // Leftover until we migrated to Dokka 1.4.30
+        maven { url "https://kotlin.bintray.com/kotlin-dev" }
         maven { url "https://jetbrains.bintray.com/kotlin-native-dependencies" }
         maven { url "https://plugins.gradle.org/m2/" }
+        maven { url "https://maven.pkg.jetbrains.space/kotlin/p/kotlin/dev" }
     }
 
     dependencies {
@@ -150,9 +143,6 @@ allprojects {
          */
         google()
         mavenCentral()
-        // Future replacement for kotlin-dev, with cache redirector
-        maven { url "https://cache-redirector.jetbrains.com/maven.pkg.jetbrains.space/kotlin/p/kotlin/dev" }
-        maven { url "https://kotlin.bintray.com/kotlinx" }
     }
 }
 
@@ -163,9 +153,9 @@ configure(subprojects.findAll { !sourceless.contains(it.name) && it.name != core
     apply plugin: "kotlin-${platform}-conventions"
     dependencies {
         // See comment below for rationale, it will be replaced with "project" dependency
-        compile project(":$coreModule")
+        api project(":$coreModule")
         // the only way IDEA can resolve test classes
-        testCompile project(":$coreModule").kotlin.targets.jvm.compilations.test.output.allOutputs
+        testImplementation project(":$coreModule").kotlin.targets.jvm.compilations.test.output.allOutputs
     }
 }
 
@@ -243,7 +233,7 @@ configure(subprojects.findAll { !unpublished.contains(it.name) }) {
     if (it.name != 'kotlinx-coroutines-bom') {
         apply from: rootProject.file('gradle/dokka.gradle')
     }
-    apply from: rootProject.file('gradle/publish-bintray.gradle')
+    apply from: rootProject.file('gradle/publish.gradle')
 }
 
 configure(subprojects.findAll { !unpublished.contains(it.name) }) {

buildSrc/build.gradle.kts

@@ -17,8 +17,10 @@ repositories {
         maven("https://cache-redirector.jetbrains.com/dl.bintray.com/kotlin/kotlin-dev")
     } else {
         maven("https://plugins.gradle.org/m2")
+        // Leftover until we migrated to Dokka 1.4.30
         maven("https://dl.bintray.com/kotlin/kotlin-dev")
     }
+    maven("https://maven.pkg.jetbrains.space/kotlin/p/kotlin/dev")
 
     if (buildSnapshotTrain) {
         mavenLocal()

buildSrc/src/main/kotlin/Publishing.kt

@@ -62,20 +62,6 @@ fun configureMavenPublication(rh: RepositoryHandler, project: Project) {
     }
 }
 
-fun configureBintrayPublication(rh: RepositoryHandler, project: Project) {
-    rh.maven {
-        val user = "kotlin"
-        val repo = "kotlinx"
-        val name = "kotlinx.coroutines"
-        url = URI("https://api.bintray.com/maven/$user/$repo/$name/;publish=0;override=0")
-
-        credentials {
-            username = project.findProperty("bintrayUser") as? String ?: System.getenv("BINTRAY_USER")
-            password = project.findProperty("bintrayApiKey") as? String ?: System.getenv("BINTRAY_API_KEY")
-        }
-    }
-}
-
 fun signPublicationIfKeyPresent(project: Project, publication: MavenPublication) {
     val keyId = project.getSensitiveProperty("libs.sign.key.id")
     val signingKey = project.getSensitiveProperty("libs.sign.key.private")

buildSrc/src/main/kotlin/kotlin-jvm-conventions.gradle.kts

@@ -22,12 +22,12 @@ if (rootProject.extra.get("jvm_ir_enabled") as Boolean) {
 }
 
 dependencies {
-    testCompile(kotlin("test"))
+    testImplementation(kotlin("test"))
     // Workaround to make addSuppressed work in tests
-    testCompile(kotlin("reflect"))
-    testCompile(kotlin("stdlib-jdk7"))
-    testCompile(kotlin("test-junit"))
-    testCompile("junit:junit:${version("junit")}")
+    testImplementation(kotlin("reflect"))
+    testImplementation(kotlin("stdlib-jdk7"))
+    testImplementation(kotlin("test-junit"))
+    testImplementation("junit:junit:${version("junit")}")
 }
 
 tasks.compileKotlin {

docs/topics/composing-suspending-functions.md

@@ -24,7 +24,7 @@ suspend fun doSomethingUsefulTwo(): Int {
 
 What do we do if we need them to be invoked _sequentially_ — first `doSomethingUsefulOne` _and then_ 
 `doSomethingUsefulTwo`, and compute the sum of their results? 
-In practice we do this if we use the result of the first function to make a decision on whether we need 
+In practice, we do this if we use the result of the first function to make a decision on whether we need 
 to invoke the second one or to decide on how to invoke it.
 
 We use a normal sequential invocation, because the code in the coroutine, just like in the regular 
@@ -190,18 +190,26 @@ standard `lazy` function in cases when computation of the value involves suspend
 ## Async-style functions
 
 We can define async-style functions that invoke `doSomethingUsefulOne` and `doSomethingUsefulTwo`
-_asynchronously_ using the [async] coroutine builder with an explicit [GlobalScope] reference.
+_asynchronously_ using the [async] coroutine builder using a [GlobalScope] reference to 
+opt-out of the structured concurrency.
 We name such functions with the 
 "...Async" suffix to highlight the fact that they only start asynchronous computation and one needs
 to use the resulting deferred value to get the result.
 
+> [GlobalScope] is a delicate API that can backfire in non-trivial ways, one of which will be explained
+> below, so you must explicitly opt-in into using `GlobalScope` with `@OptIn(DelicateCoroutinesApi::class)`. 
+>
+{type="note"}
+
 ```kotlin
 // The result type of somethingUsefulOneAsync is Deferred<Int>
+@OptIn(DelicateCoroutinesApi::class)
 fun somethingUsefulOneAsync() = GlobalScope.async {
     doSomethingUsefulOne()
 }
 
 // The result type of somethingUsefulTwoAsync is Deferred<Int>
+@OptIn(DelicateCoroutinesApi::class)
 fun somethingUsefulTwoAsync() = GlobalScope.async {
     doSomethingUsefulTwo()
 }
@@ -236,10 +244,12 @@ fun main() {
 }
 //sampleEnd
 
+@OptIn(DelicateCoroutinesApi::class)
 fun somethingUsefulOneAsync() = GlobalScope.async {
     doSomethingUsefulOne()
 }
 
+@OptIn(DelicateCoroutinesApi::class)
 fun somethingUsefulTwoAsync() = GlobalScope.async {
     doSomethingUsefulTwo()
 }
@@ -272,9 +282,9 @@ Completed in 1085 ms
 {type="note"}
 
 Consider what happens if between the `val one = somethingUsefulOneAsync()` line and `one.await()` expression there is some logic
-error in the code and the program throws an exception and the operation that was being performed by the program aborts. 
+error in the code, and the program throws an exception, and the operation that was being performed by the program aborts. 
 Normally, a global error-handler could catch this exception, log and report the error for developers, but the program 
-could otherwise continue doing other operations. But here we have `somethingUsefulOneAsync` still running in the background,
+could otherwise continue doing other operations. However, here we have `somethingUsefulOneAsync` still running in the background,
 even though the operation that initiated it was aborted. This problem does not happen with structured
 concurrency, as shown in the section below.
 
@@ -293,7 +303,7 @@ suspend fun concurrentSum(): Int = coroutineScope {
 }
 ```
 
-This way, if something goes wrong inside the code of the `concurrentSum` function and it throws an exception,
+This way, if something goes wrong inside the code of the `concurrentSum` function, and it throws an exception,
 all the coroutines that were launched in its scope will be cancelled.
 
 <!--- CLEAR -->
@@ -403,4 +413,4 @@ Computation failed with ArithmeticException
 [CoroutineScope]: https://kotlin.github.io/kotlinx.coroutines/kotlinx-coroutines-core/kotlinx.coroutines/-coroutine-scope/index.html
 [_coroutineScope]: https://kotlin.github.io/kotlinx.coroutines/kotlinx-coroutines-core/kotlinx.coroutines/coroutine-scope.html
 
-<!--- END -->
+<!--- END -->