Kotlin · qwwdfsad · Mar 6, 2020 · Dec 13, 2019 · Dec 16, 2019 · Dec 16, 2019
diff --git a/CHANGES.md b/CHANGES.md
@@ -1,5 +1,25 @@
 # Change log for kotlinx.coroutines
 
+## Version 1.3.4
+
+### Flow
+
+* Detect missing `awaitClose` calls in `callbackFlow` to make it less error-prone when used with callbacks (#1762, #1770). This change makes `callbackFlow` **different** from `channelFlow`.
+* `ReceiveChannel.asFlow` extension is introduced (#1490).
+* Enforce exception transparency invariant in `flow` builder (#1657).
+* Proper `Dispatcher` support in `Flow` reactive integrations (#1765).
+* Batch `Subscription.request` calls in `Flow` reactive integration (#766).
+* `ObservableValue.asFlow` added to JavaFx integration module (#1695).
+* `ObservableSource.asFlow` added to RxJava2 integration module (#1768).
+
+### Other changes
+
+* `kotlinx-coroutines-core` is optimized for R8, making it much smaller for Android usages (75 KB for `1.3.4` release).
+* Performance of `Dispatchers.Default` is improved (#1704, #1706).
+* Kotlin is updated to 1.3.70.
+* `CoroutineDispatcher` and `ExecutorCoroutineDispatcher` experimental coroutine context keys are introduced (#1805).
+* Performance of various `Channel` operations is improved (#1565).
+
 ## Version 1.3.3
 
 ### Flow

diff --git a/README.md b/README.md
@@ -2,10 +2,10 @@
 
 [![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://api.bintray.com/packages/kotlin/kotlinx/kotlinx.coroutines/images/download.svg?version=1.3.3) ](https://bintray.com/kotlin/kotlinx/kotlinx.coroutines/1.3.3)
+[![Download](https://api.bintray.com/packages/kotlin/kotlinx/kotlinx.coroutines/images/download.svg?version=1.3.4) ](https://bintray.com/kotlin/kotlinx/kotlinx.coroutines/1.3.4)
 
 Library support for Kotlin coroutines with [multiplatform](#multiplatform) support.
-This is a companion version for Kotlin `1.3.61` release.
+This is a companion version for Kotlin `1.3.70` release.
 
 ```kotlin
 suspend fun main() = coroutineScope {
@@ -82,15 +82,15 @@ Add dependencies (you can also add other modules that you need):
 <dependency>
     <groupId>org.jetbrains.kotlinx</groupId>
     <artifactId>kotlinx-coroutines-core</artifactId>
-    <version>1.3.3</version>
+    <version>1.3.4</version>
 </dependency>
 ```
 
 And make sure that you use the latest Kotlin version:
 
 ```xml
 <properties>
-    <kotlin.version>1.3.61</kotlin.version>
+    <kotlin.version>1.3.70</kotlin.version>
 </properties>
 ```
 
@@ -100,15 +100,15 @@ Add dependencies (you can also add other modules that you need):
 
 ```groovy
 dependencies {
-    implementation 'org.jetbrains.kotlinx:kotlinx-coroutines-core:1.3.3'
+    implementation 'org.jetbrains.kotlinx:kotlinx-coroutines-core:1.3.4'
 }
 ```
 
 And make sure that you use the latest Kotlin version:
 
 ```groovy
 buildscript {
-    ext.kotlin_version = '1.3.61'
+    ext.kotlin_version = '1.3.70'
 }
 ```
 
@@ -126,15 +126,15 @@ Add dependencies (you can also add other modules that you need):
 
 ```groovy
 dependencies {
-    implementation("org.jetbrains.kotlinx:kotlinx-coroutines-core:1.3.3")
+    implementation("org.jetbrains.kotlinx:kotlinx-coroutines-core:1.3.4")
 }
 ```
 
 And make sure that you use the latest Kotlin version:
 
 ```groovy
 plugins {
-    kotlin("jvm") version "1.3.61"
+    kotlin("jvm") version "1.3.70"
 }
 ```
 
@@ -145,7 +145,7 @@ Make sure that you have either `jcenter()` or `mavenCentral()` in the list of re
 Core modules of `kotlinx.coroutines` are also available for 
 [Kotlin/JS](#js) and [Kotlin/Native](#native).
 In common code that should get compiled for different platforms, add dependency to  
-[`kotlinx-coroutines-core-common`](https://search.maven.org/artifact/org.jetbrains.kotlinx/kotlinx-coroutines-core-common/1.3.3/jar)
+[`kotlinx-coroutines-core-common`](https://search.maven.org/artifact/org.jetbrains.kotlinx/kotlinx-coroutines-core-common/1.3.4/jar)
 (follow the link to get the dependency declaration snippet).
 
 ### Android
@@ -154,7 +154,7 @@ Add [`kotlinx-coroutines-android`](ui/kotlinx-coroutines-android)
 module as dependency when using `kotlinx.coroutines` on Android:
 
 ```groovy
-implementation 'org.jetbrains.kotlinx:kotlinx-coroutines-android:1.3.3'
+implementation 'org.jetbrains.kotlinx:kotlinx-coroutines-android:1.3.4'
 ```
 
 This gives you access to Android [Dispatchers.Main]
@@ -164,24 +164,21 @@ threads are handled by Android runtime.
 
 #### R8 and ProGuard
 
-For R8 no actions required, it will take obfuscation rules from the jar.
-
-For Proguard  you need to add options from [coroutines.pro](kotlinx-coroutines-core/jvm/resources/META-INF/proguard/coroutines.pro) to your rules manually.
-
-R8 is a replacement for ProGuard in Android ecosystem, it is enabled by default since Android gradle plugin 3.4.0 (3.3.0-beta also had it enabled).
+R8 and ProGuard rules are bundled into the [`kotlinx-coroutines-android`](ui/kotlinx-coroutines-android) module.
+For more details see ["Optimization" section for Android](ui/kotlinx-coroutines-android/README.md#optimization). 
 
 ### JS
 
 [Kotlin/JS](https://kotlinlang.org/docs/reference/js-overview.html) version of `kotlinx.coroutines` is published as 
-[`kotlinx-coroutines-core-js`](https://search.maven.org/artifact/org.jetbrains.kotlinx/kotlinx-coroutines-core-js/1.3.3/jar)
+[`kotlinx-coroutines-core-js`](https://search.maven.org/artifact/org.jetbrains.kotlinx/kotlinx-coroutines-core-js/1.3.4/jar)
 (follow the link to get the dependency declaration snippet).
 
 You can also use [`kotlinx-coroutines-core`](https://www.npmjs.com/package/kotlinx-coroutines-core) package via NPM. 
 
 ### Native
 
 [Kotlin/Native](https://kotlinlang.org/docs/reference/native-overview.html) version of `kotlinx.coroutines` is published as 
-[`kotlinx-coroutines-core-native`](https://search.maven.org/artifact/org.jetbrains.kotlinx/kotlinx-coroutines-core-native/1.3.3/jar)
+[`kotlinx-coroutines-core-native`](https://search.maven.org/artifact/org.jetbrains.kotlinx/kotlinx-coroutines-core-native/1.3.4/jar)
 (follow the link to get the dependency declaration snippet).
 
 Only single-threaded code (JS-style) on Kotlin/Native is currently supported. 
@@ -203,8 +200,9 @@ to Gradle (in Preferences -> Build, Execution, Deployment -> Build Tools -> Grad
 
 ### Requirements
 
-* JDK >= 1.8 referred to by the `JAVA_HOME` environment variable. JDK must include JavaFX.
+* JDK >= 11 referred to by the `JAVA_HOME` environment variable.
 * JDK 1.6 referred to by the `JDK_16` environment variable. It is okay to have `JDK_16` pointing to `JAVA_HOME` for external contributions.
+* JDK 1.8 referred to by the `JDK_18` environment variable. Only used by nightly stress-tests. It is okay to have `JDK_16` pointing to `JAVA_HOME` for external contributions.
 
 ## Contributions and releases
 
@@ -217,6 +215,12 @@ The `develop` branch is pushed to `master` during release.
 
 * Full release procedure checklist is [here](RELEASE.md).
 * Steps for contributing new integration modules are explained [here](integration/README.md#Contributing).
+* Use [Knit](https://github.com/Kotlin/kotlinx-knit/blob/master/README.md) for updates to documentation:
+  * In project root directory run `./gradlew knit`.
+  * Commit updated documents and examples together with other changes.
+* Use [Binary Compatibility Validator](https://github.com/Kotlin/binary-compatibility-validator/blob/master/README.md) for updates to public API:
+  * In project root directory run `./gradlew apiDump`. 
+  * Commit updated API index together with other changes.
 
 <!--- MODULE kotlinx-coroutines-core -->
 <!--- INDEX kotlinx.coroutines -->

diff --git a/RELEASE.md b/RELEASE.md
@@ -53,7 +53,8 @@ To release new `<version>` of `kotlinx-coroutines`:
    * Create a release named `<version>`. 
    * Cut & paste lines from [`CHANGES.md`](CHANGES.md) into description.    
 
-3. Build and publish documentation for web-site: <br>
+3. Build and publish documentation for web-site
+   (make sure you have [Docker](https://www.docker.com/) installed first): <br>
    `site/deploy.sh <version> push`
 
 4. In [Bintray](https://bintray.com/kotlin/kotlinx/kotlinx.coroutines) admin interface:

diff --git a/benchmarks/build.gradle b/benchmarks/build.gradle
@@ -1,5 +1,5 @@
 /*
- * Copyright 2016-2018 JetBrains s.r.o. Use of this source code is governed by the Apache 2.0 license.
+ * Copyright 2016-2020 JetBrains s.r.o. Use of this source code is governed by the Apache 2.0 license.
  */
 sourceCompatibility = 1.8
 targetCompatibility = 1.8
@@ -74,4 +74,6 @@ dependencies {
     compile "org.openjdk.jmh:jmh-core:1.21"
     compile 'com.typesafe.akka:akka-actor_2.12:2.5.0'
     compile project(':kotlinx-coroutines-core')
+    // add jmh dependency on main
+    jmh sourceSets.main.runtimeClasspath
 }
diff --git a/benchmarks/scripts/generate_plots_flow_flatten_merge.py b/benchmarks/scripts/generate_plots_flow_flatten_merge.py
@@ -0,0 +1,75 @@
+# To run this script run the command 'python3 scripts/generate_plots_flow_flatten_merge.py' in the /benchmarks folder
+
+
+import pandas as pd
+import sys
+import locale
+import matplotlib.pyplot as plt
+from matplotlib.ticker import FormatStrFormatter
+
+input_file = "build/reports/jmh/results.csv"
+output_file = "out/flow-flatten-merge.svg"
+# Please change the value of this variable according to the FlowFlattenMergeBenchmarkKt.ELEMENTS
+elements = 100000
+benchmark_name = "benchmarks.flow.FlowFlattenMergeBenchmark.flattenMerge"
+csv_columns = ["Benchmark", "Score", "Unit", "Param: concurrency", "Param: flowsNumberStrategy"]
+rename_columns = {"Benchmark": "benchmark", "Score" : "score", "Unit" : "unit",
+                  "Param: concurrency" : "concurrency", "Param: flowsNumberStrategy" : "flows"}
+
+markers = ['.', 'v', '^', '1', '2', '8', 'p', 'P', 'x', 'D', 'd', 's']
+colours = ['red', 'gold', 'sienna', 'olivedrab', 'lightseagreen', 'navy', 'blue', 'm', 'crimson', 'yellow', 'orangered', 'slateblue', 'aqua', 'black', 'silver']
+
+def next_colour():
+    i = 0
+    while True:
+        yield colours[i % len(colours)]
+        i += 1
+
+def next_marker():
+    i = 0
+    while True:
+        yield markers[i % len(markers)]
+        i += 1
+
+def draw(data, plt):
+    plt.xscale('log', basex=2)
+    plt.gca().xaxis.set_major_formatter(FormatStrFormatter('%0.f'))
+    plt.grid(linewidth='0.5', color='lightgray')
+    if data.unit.unique()[0] != "ops/s":
+        print("Unexpected time unit: " + data.unit.unique()[0])
+        sys.exit(1)
+    plt.ylabel("elements / ms")
+    plt.xlabel('concurrency')
+    plt.xticks(data.concurrency.unique())
+
+    colour_gen = next_colour()
+    marker_gen = next_marker()
+    for flows in data.flows.unique():
+        gen_colour = next(colour_gen)
+        gen_marker = next(marker_gen)
+        res = data[(data.flows == flows)]
+#         plt.plot(res.concurrency, res.score*elements/1000, label="flows={}".format(flows), color=gen_colour, marker=gen_marker)
+        plt.errorbar(x=res.concurrency, y=res.score*elements/1000, yerr=res.score_error*elements/1000, solid_capstyle='projecting',
+                     label="flows={}".format(flows), capsize=4, color=gen_colour, linewidth=2.2)
+
+langlocale = locale.getdefaultlocale()[0]
+locale.setlocale(locale.LC_ALL, langlocale)
+dp = locale.localeconv()['decimal_point']
+if dp == ",":
+    csv_columns.append("Score Error (99,9%)")
+    rename_columns["Score Error (99,9%)"] = "score_error"
+elif dp == ".":
+    csv_columns.append("Score Error (99.9%)")
+    rename_columns["Score Error (99.9%)"] = "score_error"
+else:
+    print("Unexpected locale delimeter: " + dp)
+    sys.exit(1)
+data = pd.read_csv(input_file, sep=",", decimal=dp)
+data = data[csv_columns].rename(columns=rename_columns)
+data = data[(data.benchmark == benchmark_name)]
+plt.rcParams.update({'font.size': 15})
+plt.figure(figsize=(12.5, 10))
+draw(data, plt)
+plt.legend(loc='upper center', borderpad=0, bbox_to_anchor=(0.5, 1.3), ncol=2, frameon=False, borderaxespad=2, prop={'size': 15})
+plt.tight_layout(pad=12, w_pad=2, h_pad=1)
+plt.savefig(output_file, bbox_inches='tight')
diff --git a/benchmarks/src/jmh/java/benchmarks/flow/scrabble/RxJava2PlaysScrabble.java b/benchmarks/src/jmh/java/benchmarks/flow/scrabble/RxJava2PlaysScrabble.java
@@ -1,5 +1,5 @@
 /*
- * Copyright 2016-2019 JetBrains s.r.o. Use of this source code is governed by the Apache 2.0 license.
+ * Copyright 2016-2020 JetBrains s.r.o. Use of this source code is governed by the Apache 2.0 license.
  */
 
 package benchmarks.flow.scrabble;
@@ -160,4 +160,4 @@ public List<Entry<Integer, List<String>>> play() throws Exception {
                     .blockingGet() ;
         return finalList2 ;
     }
-}
+}
diff --git a/benchmarks/src/jmh/java/benchmarks/flow/scrabble/RxJava2PlaysScrabbleOpt.java b/benchmarks/src/jmh/java/benchmarks/flow/scrabble/RxJava2PlaysScrabbleOpt.java
@@ -1,5 +1,5 @@
 /*
- * Copyright 2016-2019 JetBrains s.r.o. Use of this source code is governed by the Apache 2.0 license.
+ * Copyright 2016-2020 JetBrains s.r.o. Use of this source code is governed by the Apache 2.0 license.
  */
 
 package benchmarks.flow.scrabble;
@@ -171,4 +171,4 @@ public List<Entry<Integer, List<String>>> play() throws Exception {
 
         return finalList2 ;
     }
-}
+}
diff --git a/benchmarks/src/jmh/java/benchmarks/flow/scrabble/optimizations/FlowableCharSequence.java b/benchmarks/src/jmh/java/benchmarks/flow/scrabble/optimizations/FlowableCharSequence.java
@@ -1,5 +1,5 @@
 /*
- * Copyright 2016-2019 JetBrains s.r.o. Use of this source code is governed by the Apache 2.0 license.
+ * Copyright 2016-2020 JetBrains s.r.o. Use of this source code is governed by the Apache 2.0 license.
  */
 
 package benchmarks.flow.scrabble.optimizations;

diff --git a/benchmarks/src/jmh/java/benchmarks/flow/scrabble/optimizations/FlowableSplit.java b/benchmarks/src/jmh/java/benchmarks/flow/scrabble/optimizations/FlowableSplit.java
@@ -1,5 +1,5 @@
 /*
- * Copyright 2016-2019 JetBrains s.r.o. Use of this source code is governed by the Apache 2.0 license.
+ * Copyright 2016-2020 JetBrains s.r.o. Use of this source code is governed by the Apache 2.0 license.
  */
 
 package benchmarks.flow.scrabble.optimizations;

diff --git a/benchmarks/src/jmh/java/benchmarks/flow/scrabble/optimizations/StringFlowable.java b/benchmarks/src/jmh/java/benchmarks/flow/scrabble/optimizations/StringFlowable.java
@@ -1,5 +1,5 @@
 /*
- * Copyright 2016-2019 JetBrains s.r.o. Use of this source code is governed by the Apache 2.0 license.
+ * Copyright 2016-2020 JetBrains s.r.o. Use of this source code is governed by the Apache 2.0 license.
  */
 
 package benchmarks.flow.scrabble.optimizations;

diff --git a/benchmarks/src/jmh/kotlin/benchmarks/ChannelProducerConsumerBenchmark.kt b/benchmarks/src/jmh/kotlin/benchmarks/ChannelProducerConsumerBenchmark.kt
@@ -1,5 +1,5 @@
 /*
- * Copyright 2016-2019 JetBrains s.r.o. Use of this source code is governed by the Apache 2.0 license.
+ * Copyright 2016-2020 JetBrains s.r.o. Use of this source code is governed by the Apache 2.0 license.
  */
 
 package benchmarks
@@ -147,4 +147,4 @@ private fun doWork(): Unit = Blackhole.consumeCPU(ThreadLocalRandom.current().ne
 
 private const val WORK_MIN = 50L
 private const val WORK_MAX = 100L
-private const val APPROX_BATCH_SIZE = 100000
+private const val APPROX_BATCH_SIZE = 100000
diff --git a/benchmarks/src/jmh/kotlin/benchmarks/ChannelSinkBenchmark.kt b/benchmarks/src/jmh/kotlin/benchmarks/ChannelSinkBenchmark.kt
@@ -1,5 +1,5 @@
 /*
- * Copyright 2016-2018 JetBrains s.r.o. Use of this source code is governed by the Apache 2.0 license.
+ * Copyright 2016-2020 JetBrains s.r.o. Use of this source code is governed by the Apache 2.0 license.
  */
 
 package benchmarks

diff --git a/benchmarks/src/jmh/kotlin/benchmarks/ParametrizedDispatcherBase.kt b/benchmarks/src/jmh/kotlin/benchmarks/ParametrizedDispatcherBase.kt
@@ -1,5 +1,5 @@
 /*
- * Copyright 2016-2018 JetBrains s.r.o. Use of this source code is governed by the Apache 2.0 license.
+ * Copyright 2016-2020 JetBrains s.r.o. Use of this source code is governed by the Apache 2.0 license.
  */
 
 package benchmarks
@@ -44,4 +44,4 @@ abstract class ParametrizedDispatcherBase : CoroutineScope {
         closeable?.close()
     }
 
-}
+}