Update shutdown API documentation

Author: dounan

api/src/main/java/io/grpc/Server.java

@@ -104,8 +104,12 @@ public List<ServerServiceDefinition> getMutableServices() {
 
   /**
    * Initiates an orderly shutdown in which preexisting calls continue but new calls are rejected.
-   * This call will not wait for preexisting calls finish before returning. After this call returns,
-   * this server has released the listening socket(s) and may be reused by another server.
+   * After this call returns, this server has released the listening socket(s) and may be reused by
+   * another server.
+   *
+   * Note that this method will not wait for preexisting calls to finish before returning.
+   * {@link #awaitTermination()} or {@link #awaitTermination(long, TimeUnit)} needs to be called to
+   * wait for existing calls to finish.
    *
    * @return {@code this} object
    * @since 1.0.0

examples/build.gradle

@@ -22,7 +22,7 @@ targetCompatibility = 1.7
 
 // Feel free to delete the comment at the next line. It is just for safely
 // updating the version in our release process.
-def grpcVersion = '1.27.0-SNAPSHOT' // CURRENT_GRPC_VERSION
+def grpcVersion = '1.24.2' // CURRENT_GRPC_VERSION
 def protobufVersion = '3.11.0'
 def protocVersion = protobufVersion
 

examples/src/main/java/io/grpc/examples/helloworld/HelloWorldServer.java

@@ -34,17 +34,15 @@ public class HelloWorldServer {
   private void start() throws IOException {
     /* The port on which the server should run */
     int port = 50051;
-    server = ServerBuilder.forPort(port)
-        .addService(new GreeterImpl())
-        .build()
-        .start();
+    server = ServerBuilder.forPort(port).addService(new GreeterImpl()).build().start();
     logger.info("Server started, listening on " + port);
     Runtime.getRuntime().addShutdownHook(new Thread() {
       @Override
       public void run() {
-        // Use stderr here since the logger may have been reset by its JVM shutdown hook.
+        // Use stderr here since the logger may have been reset by its JVM shutdown
+        // hook.
         System.err.println("*** shutting down gRPC server since JVM is shutting down");
-        HelloWorldServer.this.stop();
+        // HelloWorldServer.this.stop();
         System.err.println("*** server shut down");
       }
     });
@@ -61,7 +59,8 @@ private void stop() {
   }
 
   /**
-   * Await termination on the main thread since the grpc library uses daemon threads.
+   * Await termination on the main thread since the grpc library uses daemon
+   * threads.
    */
   private void blockUntilShutdown() throws InterruptedException {
     if (server != null) {
@@ -82,6 +81,13 @@ static class GreeterImpl extends GreeterGrpc.GreeterImplBase {
 
     @Override
     public void sayHello(HelloRequest req, StreamObserver<HelloReply> responseObserver) {
+      logger.info("!!! Received call");
+      try {
+        Thread.sleep(15000);
+      } catch (InterruptedException e) {
+        // TODO Auto-generated catch block
+        e.printStackTrace();
+      }
       HelloReply reply = HelloReply.newBuilder().setMessage("Hello " + req.getName()).build();
       responseObserver.onNext(reply);
       responseObserver.onCompleted();