Remove context injection from JDK9 Flow integration

Author: dkhalanskyjb

binary-compatibility-validator/reference-public-api/kotlinx-coroutines-jdk9.txt

@@ -7,10 +7,6 @@ public final class kotlinx/coroutines/jdk9/AwaitKt {
 	public static final fun awaitSingle (Ljava/util/concurrent/Flow$Publisher;Lkotlin/coroutines/Continuation;)Ljava/lang/Object;
 }
 
-public abstract interface class kotlinx/coroutines/jdk9/ContextInjector {
-	public abstract fun injectCoroutineContext (Ljava/util/concurrent/Flow$Publisher;Lkotlin/coroutines/CoroutineContext;)Ljava/util/concurrent/Flow$Publisher;
-}
-
 public final class kotlinx/coroutines/jdk9/FlowSubscription : kotlinx/coroutines/AbstractCoroutine, java/util/concurrent/Flow$Subscription {
 	public final field flow Lkotlinx/coroutines/flow/Flow;
 	public final field subscriber Ljava/util/concurrent/Flow$Subscriber;

reactive/kotlinx-coroutines-jdk9/src/Await.kt

@@ -82,16 +82,6 @@ public suspend fun <T> Publisher<T>.awaitSingle(): T = awaitOne(Mode.SINGLE)
 
 // ------------------------ private ------------------------
 
-// ContextInjector service is implemented in `kotlinx-coroutines-reactor` module only.
-// If `kotlinx-coroutines-reactor` module is not included, the list is empty.
-private val contextInjectors: Array<ContextInjector> =
-    ServiceLoader.load(ContextInjector::class.java, ContextInjector::class.java.classLoader).iterator().asSequence().toList().toTypedArray() // R8 opto
-
-private fun <T> Publisher<T>.injectCoroutineContext(coroutineContext: CoroutineContext) =
-    contextInjectors.fold(this) { pub, contextInjector ->
-        contextInjector.injectCoroutineContext(pub, coroutineContext)
-    }
-
 private enum class Mode(val s: String) {
     FIRST("awaitFirst"),
     FIRST_OR_DEFAULT("awaitFirstOrDefault"),
@@ -104,7 +94,7 @@ private suspend fun <T> Publisher<T>.awaitOne(
     mode: Mode,
     default: T? = null
 ): T = suspendCancellableCoroutine { cont ->
-    injectCoroutineContext(cont.context).subscribe(object : Subscriber<T> {
+    subscribe(object : Subscriber<T> {
         private lateinit var subscription: Subscription
         private var value: T? = null
         private var seenValue = false

reactive/kotlinx-coroutines-jdk9/src/ContextInjector.kt

@@ -65,7 +65,7 @@ private class PublisherAsFlow<T : Any>(
         val newDispatcher = context[ContinuationInterceptor]
         if (newDispatcher == null || newDispatcher == collectContext[ContinuationInterceptor]) {
             // fast path -- subscribe directly in this dispatcher
-            return collectImpl(collectContext + context, collector)
+            return collectImpl(collector)
         }
         // slow path -- produce in a separate dispatcher
         collectSlowPath(collector)
@@ -77,10 +77,10 @@ private class PublisherAsFlow<T : Any>(
         }
     }
 
-    private suspend fun collectImpl(injectContext: CoroutineContext, collector: FlowCollector<T>) {
+    private suspend fun collectImpl(collector: FlowCollector<T>) {
         val subscriber = ReactiveSubscriber<T>(capacity, requestSize)
         // inject subscribe context into publisher
-        publisher.injectCoroutineContext(injectContext).subscribe(subscriber)
+        publisher.subscribe(subscriber)
         try {
             var consumed = 0L
             while (true) {
@@ -98,7 +98,7 @@ private class PublisherAsFlow<T : Any>(
 
     // The second channel here is used for produceIn/broadcastIn and slow-path (dispatcher change)
     override suspend fun collectTo(scope: ProducerScope<T>) =
-            collectImpl(scope.coroutineContext, SendingCollector(scope.channel))
+            collectImpl(SendingCollector(scope.channel))
 }
 
 @Suppress("SubscriberImplementation")
@@ -138,15 +138,6 @@ private class ReactiveSubscriber<T : Any>(
     }
 }
 
-// ContextInjector service is implemented in `kotlinx-coroutines-reactor` module only.
-// If `kotlinx-coroutines-reactor` module is not included, the list is empty.
-private val contextInjectors: List<ContextInjector> =
-    ServiceLoader.load(ContextInjector::class.java, ContextInjector::class.java.classLoader).toList()
-
-private fun <T> Publisher<T>.injectCoroutineContext(coroutineContext: CoroutineContext) =
-    contextInjectors.fold(this) { pub, contextInjector -> contextInjector.injectCoroutineContext(pub, coroutineContext) }
-
-
 /**
  * Adapter that transforms [Flow] into TCK-complaint [Publisher].
  * [cancel] invocation cancels the original flow.