System wide materializer (#27491)

Introduces a materializer started through an extension and then an implicit
conversion for Scala turning an implicitly available ActorSystem into a
materializer. The Java APIs has been ammended with run-methods accepting
an ActorSystem.

akka-docs/src/test/scala/docs/stream/BidiFlowDocSpec.scala

@@ -148,8 +148,6 @@ object BidiFlowDocSpec {
 class BidiFlowDocSpec extends AkkaSpec {
   import BidiFlowDocSpec._
 
-  implicit val materializer = ActorMaterializer()
-
   "A BidiFlow" must {
 
     "compose" in {

akka-docs/src/test/scala/docs/stream/CompositionDocSpec.scala

@@ -16,7 +16,6 @@ import scala.concurrent.{ Future, Promise }
 class CompositionDocSpec extends AkkaSpec {
 
   implicit val ec = system.dispatcher
-  implicit val materializer = ActorMaterializer()
 
   "nonnested flow" in {
     //#non-nested-flow

akka-docs/src/test/scala/docs/stream/FlowDocSpec.scala

@@ -4,9 +4,11 @@
 
 package docs.stream
 
-import akka.{ Done, NotUsed }
+import akka.NotUsed
 import akka.actor.{ Actor, ActorSystem, Cancellable }
-import akka.stream.{ ActorMaterializer, ClosedShape, FlowShape, Materializer, OverflowStrategy }
+import akka.stream.ActorMaterializer
+import akka.stream.Materializer
+import akka.stream.{ ClosedShape, FlowShape, OverflowStrategy }
 import akka.stream.scaladsl._
 import akka.testkit.AkkaSpec
 import docs.CompileOnlySpec
@@ -18,12 +20,6 @@ class FlowDocSpec extends AkkaSpec with CompileOnlySpec {
 
   implicit val ec = system.dispatcher
 
-  //#imports
-  import akka.stream.ActorMaterializer
-  //#imports
-
-  implicit val materializer = ActorMaterializer()
-
   "source is immutable" in {
     //#source-immutable
     val source = Source(1 to 10)
@@ -247,14 +243,6 @@ class FlowDocSpec extends AkkaSpec with CompileOnlySpec {
 
 object FlowDocSpec {
 
-  {
-    //#materializer-from-system
-    implicit val system = ActorSystem("ExampleSystem")
-
-    implicit val mat = ActorMaterializer() // created from `system`
-    //#materializer-from-system
-  }
-
   //#materializer-from-actor-context
   final class RunWithMyself extends Actor {
     implicit val mat = ActorMaterializer()

akka-docs/src/test/scala/docs/stream/FlowErrorDocSpec.scala

@@ -18,7 +18,6 @@ class FlowErrorDocSpec extends AkkaSpec {
 
   "demonstrate fail stream" in {
     //#stop
-    implicit val materializer = ActorMaterializer()
     val source = Source(0 to 5).map(100 / _)
     val result = source.runWith(Sink.fold(0)(_ + _))
     // division by zero will fail the stream and the
@@ -48,7 +47,6 @@ class FlowErrorDocSpec extends AkkaSpec {
 
   "demonstrate resume section" in {
     //#resume-section
-    implicit val materializer = ActorMaterializer()
     val decider: Supervision.Decider = {
       case _: ArithmeticException => Supervision.Resume
       case _                      => Supervision.Stop
@@ -69,7 +67,6 @@ class FlowErrorDocSpec extends AkkaSpec {
 
   "demonstrate restart section" in {
     //#restart-section
-    implicit val materializer = ActorMaterializer()
     val decider: Supervision.Decider = {
       case _: IllegalArgumentException => Supervision.Restart
       case _                           => Supervision.Stop
@@ -91,7 +88,6 @@ class FlowErrorDocSpec extends AkkaSpec {
   }
 
   "demonstrate recover" in {
-    implicit val materializer = ActorMaterializer()
     //#recover
     Source(0 to 6)
       .map(n =>
@@ -117,7 +113,6 @@ stream truncated
   }
 
   "demonstrate recoverWithRetries" in {
-    implicit val materializer = ActorMaterializer()
     //#recoverWithRetries
     val planB = Source(List("five", "six", "seven", "eight"))
 

akka-docs/src/test/scala/docs/stream/FlowStreamRefsDocSpec.scala

@@ -10,7 +10,6 @@ import akka.stream.ActorMaterializer
 import akka.stream.scaladsl._
 import akka.testkit.AkkaSpec
 import docs.CompileOnlySpec
-import scala.concurrent.Future
 
 class FlowStreamRefsDocSpec extends AkkaSpec with CompileOnlySpec {
 
@@ -91,7 +90,6 @@ class FlowStreamRefsDocSpec extends AkkaSpec with CompileOnlySpec {
 
     //#offer-sink
 
-    implicit val mat = ActorMaterializer()
     def localMetrics(): Source[String, NotUsed] = Source.single("")
 
     //#offer-sink-use
@@ -106,8 +104,6 @@ class FlowStreamRefsDocSpec extends AkkaSpec with CompileOnlySpec {
   }
 
   "show how to configure timeouts with attrs" in compileOnlySpec {
-
-    implicit val mat: ActorMaterializer = null
     //#attr-sub-timeout
     // configure the timeout for source
     import scala.concurrent.duration._

akka-docs/src/test/scala/docs/stream/GraphCyclesSpec.scala

@@ -10,8 +10,6 @@ import akka.testkit.AkkaSpec
 
 class GraphCyclesSpec extends AkkaSpec {
 
-  implicit val materializer = ActorMaterializer()
-
   "Cycle demonstration" must {
     val source = Source.fromIterator(() => Iterator.from(0))
 

akka-docs/src/test/scala/docs/stream/GraphDSLDocSpec.scala

@@ -17,8 +17,6 @@ class GraphDSLDocSpec extends AkkaSpec {
 
   implicit val ec = system.dispatcher
 
-  implicit val materializer = ActorMaterializer()
-
   "build simple graph" in {
     //format: OFF
     //#simple-graph-dsl

akka-docs/src/test/scala/docs/stream/GraphStageDocSpec.scala

@@ -18,8 +18,6 @@ import scala.collection.immutable.Iterable
 
 class GraphStageDocSpec extends AkkaSpec {
 
-  implicit val materializer = ActorMaterializer()
-
   "Demonstrate creation of GraphStage boilerplate" in {
     //#boilerplate-example
     import akka.stream.SourceShape

akka-docs/src/test/scala/docs/stream/GraphStageLoggingDocSpec.scala

@@ -12,7 +12,6 @@ import akka.testkit.{ AkkaSpec, EventFilter }
 
 class GraphStageLoggingDocSpec extends AkkaSpec("akka.loglevel = DEBUG") {
 
-  implicit val materializer = ActorMaterializer()
   implicit val ec = system.dispatcher
 
   //#operator-with-logging

akka-docs/src/test/scala/docs/stream/HubsDocSpec.scala

@@ -5,7 +5,7 @@
 package docs.stream
 
 import akka.NotUsed
-import akka.stream.{ ActorMaterializer, KillSwitches, UniqueKillSwitch }
+import akka.stream.{ KillSwitches, UniqueKillSwitch }
 import akka.stream.scaladsl._
 import akka.testkit.AkkaSpec
 import docs.CompileOnlySpec
@@ -14,7 +14,6 @@ import scala.concurrent.duration._
 import akka.stream.ThrottleMode
 
 class HubsDocSpec extends AkkaSpec with CompileOnlySpec {
-  implicit val materializer = ActorMaterializer()
 
   "Hubs" must {
 

akka-docs/src/test/scala/docs/stream/IntegrationDocSpec.scala

@@ -13,7 +13,7 @@ import akka.stream._
 
 import scala.concurrent.Future
 import akka.testkit.TestProbe
-import akka.actor.{ Actor, ActorLogging, ActorRef, Props, Status }
+import akka.actor.{ Actor, ActorLogging, ActorRef, Props }
 import com.typesafe.config.ConfigFactory
 import akka.util.Timeout
 
@@ -21,9 +21,6 @@ import scala.concurrent.ExecutionContext
 import java.util.concurrent.atomic.AtomicInteger
 
 import akka.stream.scaladsl.Flow
-import akka.Done
-import akka.actor.Status.Status
-import akka.stream.QueueOfferResult.{ Dropped, Enqueued }
 
 object IntegrationDocSpec {
   import TwitterStreamQuickstartDocSpec._
@@ -137,7 +134,6 @@ class IntegrationDocSpec extends AkkaSpec(IntegrationDocSpec.config) {
   import TwitterStreamQuickstartDocSpec._
   import IntegrationDocSpec._
 
-  implicit val materializer = ActorMaterializer()
   val ref: ActorRef = system.actorOf(Props[Translator])
 
   "ask" in {

akka-docs/src/test/scala/docs/stream/KillSwitchDocSpec.scala

@@ -5,7 +5,7 @@
 package docs.stream
 
 import akka.stream.scaladsl._
-import akka.stream.{ ActorMaterializer, DelayOverflowStrategy, KillSwitches }
+import akka.stream.{ DelayOverflowStrategy, KillSwitches }
 import akka.testkit.AkkaSpec
 import docs.CompileOnlySpec
 
@@ -14,8 +14,6 @@ import scala.concurrent.duration._
 
 class KillSwitchDocSpec extends AkkaSpec with CompileOnlySpec {
 
-  implicit val materializer = ActorMaterializer()
-
   "Unique kill switch" must {
 
     "control graph completion with shutdown" in compileOnlySpec {

akka-docs/src/test/scala/docs/stream/QuickStartDocSpec.scala

@@ -23,6 +23,7 @@ import org.scalatest.concurrent._
 
 //#main-app
 object Main extends App {
+  implicit val system = ActorSystem("QuickStart")
   // Code here
 }
 //#main-app
@@ -33,17 +34,14 @@ class QuickStartDocSpec extends WordSpec with BeforeAndAfterAll with ScalaFuture
   def println(any: Any) = () // silence printing stuff
 
   "demonstrate Source" in {
-    //#create-materializer
     implicit val system = ActorSystem("QuickStart")
-    implicit val materializer = ActorMaterializer()
-    //#create-materializer
 
     //#create-source
     val source: Source[Int, NotUsed] = Source(1 to 100)
     //#create-source
 
     //#run-source
-    source.runForeach(i => println(i))(materializer)
+    source.runForeach(i => println(i))
     //#run-source
 
     //#transform-source
@@ -68,7 +66,7 @@ class QuickStartDocSpec extends WordSpec with BeforeAndAfterAll with ScalaFuture
     //#add-streams
 
     //#run-source-and-terminate
-    val done: Future[Done] = source.runForeach(i => println(i))(materializer)
+    val done: Future[Done] = source.runForeach(i => println(i))
 
     implicit val ec = system.dispatcher
     done.onComplete(_ => system.terminate())

akka-docs/src/test/scala/docs/stream/RateTransformationDocSpec.scala

@@ -4,7 +4,6 @@
 
 package docs.stream
 
-import akka.stream._
 import akka.stream.scaladsl._
 import akka.stream.testkit.scaladsl._
 
@@ -18,8 +17,6 @@ import scala.concurrent.Await
 
 class RateTransformationDocSpec extends AkkaSpec {
 
-  implicit val materializer = ActorMaterializer()
-
   "conflate should summarize" in {
     //#conflate-summarize
     val statsFlow = Flow[Double].conflateWithSeed(immutable.Seq(_))(_ :+ _).map { s =>

akka-docs/src/test/scala/docs/stream/ReactiveStreamsDocSpec.scala

@@ -5,7 +5,6 @@
 package docs.stream
 
 import akka.NotUsed
-import akka.stream.ActorMaterializer
 import akka.stream.scaladsl.{ Flow, Sink, Source }
 import akka.stream.testkit._
 import org.reactivestreams.Processor
@@ -14,8 +13,6 @@ import akka.testkit.AkkaSpec
 class ReactiveStreamsDocSpec extends AkkaSpec {
   import TwitterStreamQuickstartDocSpec._
 
-  implicit val materializer = ActorMaterializer()
-
   //#imports
   import org.reactivestreams.Publisher
   import org.reactivestreams.Subscriber

akka-docs/src/test/scala/docs/stream/RestartDocSpec.scala

@@ -5,7 +5,7 @@
 package docs.stream
 
 import akka.NotUsed
-import akka.stream.{ ActorMaterializer, KillSwitches }
+import akka.stream.KillSwitches
 import akka.stream.scaladsl._
 import akka.testkit.AkkaSpec
 import docs.CompileOnlySpec
@@ -14,7 +14,6 @@ import scala.concurrent.duration._
 import scala.concurrent._
 
 class RestartDocSpec extends AkkaSpec with CompileOnlySpec {
-  implicit val materializer = ActorMaterializer()
   import system.dispatcher
 
   // Mock akka-http interfaces

akka-docs/src/test/scala/docs/stream/StreamBuffersRateSpec.scala

@@ -10,7 +10,6 @@ import akka.stream.scaladsl._
 import akka.testkit.AkkaSpec
 
 class StreamBuffersRateSpec extends AkkaSpec {
-  implicit val materializer = ActorMaterializer()
 
   "Demonstrate pipelining" in {
     def println(s: Any) = ()

akka-docs/src/test/scala/docs/stream/StreamPartialGraphDSLDocSpec.scala

@@ -16,8 +16,6 @@ class StreamPartialGraphDSLDocSpec extends AkkaSpec {
 
   implicit val ec = system.dispatcher
 
-  implicit val materializer = ActorMaterializer()
-
   "build with open ports" in {
     //#simple-partial-graph-dsl
     val pickMaxOfThree = GraphDSL.create() { implicit b =>

akka-docs/src/test/scala/docs/stream/StreamTestKitDocSpec.scala

@@ -6,7 +6,6 @@ package docs.stream
 
 import akka.stream._
 import akka.stream.scaladsl._
-import akka.stream.testkit._
 import akka.stream.testkit.scaladsl._
 import scala.util._
 import scala.concurrent.duration._
@@ -16,8 +15,6 @@ import akka.pattern
 
 class StreamTestKitDocSpec extends AkkaSpec {
 
-  implicit val materializer = ActorMaterializer()
-
   "strict collection" in {
     //#strict-collection
     val sinkUnderTest = Flow[Int].map(_ * 2).toMat(Sink.fold(0)(_ + _))(Keep.right)

akka-docs/src/test/scala/docs/stream/SubstreamDocSpec.scala

@@ -5,11 +5,10 @@
 package docs.stream
 
 import akka.stream.scaladsl.{ Sink, Source }
-import akka.stream.{ ActorMaterializer, SubstreamCancelStrategy }
+import akka.stream.{ SubstreamCancelStrategy }
 import akka.testkit.AkkaSpec
 
 class SubstreamDocSpec extends AkkaSpec {
-  implicit val materializer = ActorMaterializer()
 
   "generate substreams by groupBy" in {
     //#groupBy1

akka-docs/src/test/scala/docs/stream/TwitterStreamQuickstartDocSpec.scala

@@ -8,7 +8,7 @@ package docs.stream
 
 import akka.{ Done, NotUsed }
 import akka.actor.ActorSystem
-import akka.stream.{ ActorMaterializer, ClosedShape, OverflowStrategy }
+import akka.stream.{ ClosedShape, OverflowStrategy }
 import akka.stream.scaladsl._
 import scala.concurrent.Await
 import scala.concurrent.Future
@@ -79,17 +79,14 @@ class TwitterStreamQuickstartDocSpec extends AkkaSpec {
   trait Example1 {
     //#fiddle_code
     //#first-sample
-    //#materializer-setup
+    //#system-setup
     implicit val system = ActorSystem("reactive-tweets")
-    implicit val materializer = ActorMaterializer()
-    //#materializer-setup
+    //#system-setup
     //#first-sample
 
     //#fiddle_code
   }
 
-  implicit val materializer = ActorMaterializer()
-
   "filter and map" in {
     //#first-sample
 

akka-docs/src/test/scala/docs/stream/cookbook/RecipeSpec.scala

@@ -4,12 +4,10 @@
 
 package docs.stream.cookbook
 
-import akka.stream.ActorMaterializer
 import akka.testkit.AkkaSpec
 
 trait RecipeSpec extends AkkaSpec {
 
-  implicit val m = ActorMaterializer()
   type Message = String
 
 }

akka-docs/src/test/scala/docs/stream/io/StreamFileDocSpec.scala

@@ -17,7 +17,6 @@ import scala.concurrent.Future
 class StreamFileDocSpec extends AkkaSpec(UnboundedMailboxConfig) {
 
   implicit val ec = system.dispatcher
-  implicit val materializer = ActorMaterializer()
 
   // silence sysout
   def println(s: String) = ()

akka-docs/src/test/scala/docs/stream/io/StreamTcpDocSpec.scala

@@ -6,7 +6,6 @@ package docs.stream.io
 
 import java.util.concurrent.atomic.AtomicReference
 
-import akka.stream._
 import akka.stream.scaladsl.Tcp._
 import akka.stream.scaladsl._
 import akka.testkit.AkkaSpec
@@ -19,7 +18,6 @@ import akka.testkit.SocketUtil
 class StreamTcpDocSpec extends AkkaSpec {
 
   implicit val ec = system.dispatcher
-  implicit val materializer = ActorMaterializer()
 
   // silence sysout
   def println(s: String) = ()

akka-docs/src/test/scala/docs/stream/operators/SourceOperators.scala

@@ -5,7 +5,6 @@
 package docs.stream.operators
 
 import akka.actor.ActorSystem
-import akka.stream.ActorMaterializer
 import akka.testkit.TestProbe
 
 object SourceOperators {
@@ -21,7 +20,6 @@ object SourceOperators {
     import scala.concurrent.Future
 
     implicit val system: ActorSystem = ActorSystem()
-    implicit val materializer: ActorMaterializer = ActorMaterializer()
 
     val source: Source[Int, NotUsed] = Source.fromFuture(Future.successful(10))
     val sink: Sink[Int, Future[Done]] = Sink.foreach((i: Int) => println(i))
@@ -40,7 +38,6 @@ object SourceOperators {
     import akka.stream.scaladsl._
 
     implicit val system: ActorSystem = ActorSystem()
-    implicit val materializer: ActorMaterializer = ActorMaterializer()
     val bufferSize = 100
 
     val source: Source[Any, ActorRef] = Source.actorRef[Any](bufferSize, OverflowStrategy.dropHead)
@@ -63,7 +60,6 @@ object SourceOperators {
     import akka.stream.scaladsl._
 
     implicit val system: ActorSystem = ActorSystem()
-    implicit val materializer: ActorMaterializer = ActorMaterializer()
     val probe = TestProbe()
 
     val source: Source[Any, ActorRef] = Source.actorRefWithAck[Any]("ack")

akka-docs/src/test/scala/docs/stream/operators/sourceorflow/Scan.scala

@@ -11,7 +11,6 @@ object Scan {
     import akka.stream.ActorMaterializer
 
     implicit val system: ActorSystem = ActorSystem()
-    implicit val materializer: ActorMaterializer = ActorMaterializer()
 
     //#scan
     val source = Source(1 to 5)