Merge pull request #1638 from ChristopherDavenport/fixImmediatelyRetu…

…rningServe Fix immediately returning serve
http4s · Jan 24, 2018 · 7d3ebff · 7d3ebff
2 parents 29671c0 + 3f9afe4
commit 7d3ebff
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diff --git a/docs/src/main/tut/service.md b/docs/src/main/tut/service.md
@@ -52,7 +52,7 @@ Wherever you are in your studies, let's create our first
 `HttpService`.  Start by pasting these imports into your SBT console:
 
 ```tut:book
-import cats.effect._, org.http4s._, org.http4s.dsl.io._
+import cats.effect._, org.http4s._, org.http4s.dsl.io._, scala.concurrent.ExecutionContext.Implicits.global
 ```
 
 Using the [http4s-dsl], we can construct an `HttpService` by pattern

diff --git a/examples/blaze/src/main/scala/com/example/http4s/blaze/BlazeMetricsExample.scala b/examples/blaze/src/main/scala/com/example/http4s/blaze/BlazeMetricsExample.scala
@@ -9,6 +9,7 @@ import org.http4s.HttpService
 import org.http4s.server.blaze.BlazeBuilder
 import org.http4s.server.metrics._
 import org.http4s.server.{HttpMiddleware, Router}
+import scala.concurrent.ExecutionContext.Implicits.global
 
 object BlazeMetricsExample extends BlazeMetricsExampleApp[IO]
 

diff --git a/examples/docker/src/main/scala/com/example/http4s/Example.scala b/examples/docker/src/main/scala/com/example/http4s/Example.scala
@@ -6,6 +6,7 @@ import fs2.StreamApp.ExitCode
 import org.http4s._
 import org.http4s.dsl.Http4sDsl
 import org.http4s.server.blaze.BlazeBuilder
+import scala.concurrent.ExecutionContext.Implicits.global
 
 object Example extends StreamApp[IO] with Http4sDsl[IO] {
   val service: HttpService[IO] = HttpService[IO] {

diff --git a/examples/jetty/src/main/scala/com/example/http4s/jetty/JettyExample.scala b/examples/jetty/src/main/scala/com/example/http4s/jetty/JettyExample.scala
@@ -9,6 +9,7 @@ import org.http4s.dsl.Http4sDsl
 import org.http4s.server.HttpMiddleware
 import org.http4s.server.jetty.JettyBuilder
 import org.http4s.server.metrics._
+import scala.concurrent.ExecutionContext.Implicits.global
 
 object JettyExample extends JettyExampleApp[IO]
 

diff --git a/examples/src/main/scala/com/example/http4s/ssl/SslClasspathExample.scala b/examples/src/main/scala/com/example/http4s/ssl/SslClasspathExample.scala
@@ -9,6 +9,7 @@ import fs2.{Scheduler, Stream, StreamApp}
 import org.http4s.server.middleware.HSTS
 import org.http4s.server.{SSLContextSupport, ServerBuilder}
 import java.security.{KeyStore, Security}
+import scala.concurrent.ExecutionContext.Implicits.global
 
 abstract class SslClasspathExample[F[_]: Effect] extends StreamApp[F] {
 

diff --git a/examples/src/main/scala/com/example/http4s/ssl/SslExample.scala b/examples/src/main/scala/com/example/http4s/ssl/SslExample.scala
@@ -8,6 +8,7 @@ import java.nio.file.Paths
 import org.http4s.server.SSLKeyStoreSupport.StoreInfo
 import org.http4s.server.middleware.HSTS
 import org.http4s.server.{SSLKeyStoreSupport, ServerBuilder}
+import scala.concurrent.ExecutionContext.Implicits.global
 
 abstract class SslExample[F[_]: Effect] extends StreamApp[F] {
   // TODO: Reference server.jks from something other than one child down.

diff --git a/examples/tomcat/src/main/scala/com/example/http4s/tomcat/TomcatExample.scala b/examples/tomcat/src/main/scala/com/example/http4s/tomcat/TomcatExample.scala
@@ -8,6 +8,7 @@ import fs2.StreamApp.ExitCode
 import org.http4s.server.HttpMiddleware
 import org.http4s.server.metrics._
 import org.http4s.server.tomcat.TomcatBuilder
+import scala.concurrent.ExecutionContext.Implicits.global
 
 object TomcatExample extends TomcatExampleApp[IO]
 

diff --git a/server/src/main/scala/org/http4s/server/ServerBuilder.scala b/server/src/main/scala/org/http4s/server/ServerBuilder.scala
@@ -1,12 +1,15 @@
 package org.http4s
 package server
 
+import cats.implicits._
 import cats.effect._
 import fs2.StreamApp.ExitCode
 import fs2._
 import java.net.{InetAddress, InetSocketAddress}
 import java.util.concurrent.ExecutorService
 import javax.net.ssl.SSLContext
+import fs2.async.immutable.Signal
+import fs2.async.Ref
 import org.http4s.server.SSLKeyStoreSupport.StoreInfo
 import scala.collection.immutable
 import scala.concurrent.ExecutionContext
@@ -53,10 +56,25 @@ trait ServerBuilder[F[_]] {
     * Runs the server as a process that never emits.  Useful for a server
     * that runs for the rest of the JVM's life.
     */
-  final def serve(implicit F: Async[F]): Stream[F, ExitCode] =
+  final def serve(implicit F: Effect[F], ec: ExecutionContext): Stream[F, ExitCode] =
+    for {
+      signal <- Stream.eval(async.signalOf[F, Boolean](false))
+      exitCode <- Stream.eval(async.refOf[F, ExitCode](ExitCode.Success))
+      serve <- serveWhile(signal, exitCode)
+    } yield serve
+
+  /**
+    * Runs the server as a Stream that emits only when the terminated signal becomes true.
+    * Useful for servers with associated lifetime behaviors.
+    */
+  final def serveWhile(
+      terminateWhenTrue: Signal[F, Boolean],
+      exitWith: Ref[F, ExitCode]): Stream[F, ExitCode] =
     Stream.bracket(start)(
-      (_: Server[F]) => Stream.eval_(F.async[Unit](cb => cb(Right(())))),
-      _.shutdown)
+      (_: Server[F]) =>
+        terminateWhenTrue.discrete.takeWhile(_ === false).drain ++ Stream.eval(exitWith.get),
+      _.shutdown
+    )
 
   /** Set the banner to display when the server starts up */
   def withBanner(banner: immutable.Seq[String]): Self