From b7d64d12da9eafeb9bfa725cf371ffa6e265837c Mon Sep 17 00:00:00 2001
From: Gary Russell <grussell@pivotal.io>
Date: Thu, 12 Feb 2015 16:44:16 -0500
Subject: [PATCH] Fix Race Condition in Test Interceptor (TCP)

The HelloWorldInterceptor (server side) set the
negotiated flag after sending the handshake back.
The next message could be received before the flag
was set and caused the test to fail.

Synchronize the server-side handshaking code so that
we don't start processing the next message before
the negotiated flag is set.

Leave the diagnostic log settings in place for now.
---
 .../tcp/connection/HelloWorldInterceptor.java | 60 +++++++++++--------
 1 file changed, 35 insertions(+), 25 deletions(-)

diff --git a/spring-integration-ip/src/test/java/org/springframework/integration/ip/tcp/connection/HelloWorldInterceptor.java b/spring-integration-ip/src/test/java/org/springframework/integration/ip/tcp/connection/HelloWorldInterceptor.java
index 3760daada7..6ced05cf8c 100644
--- a/spring-integration-ip/src/test/java/org/springframework/integration/ip/tcp/connection/HelloWorldInterceptor.java
+++ b/spring-integration-ip/src/test/java/org/springframework/integration/ip/tcp/connection/HelloWorldInterceptor.java
@@ -61,36 +61,45 @@ public class HelloWorldInterceptor extends TcpConnectionInterceptorSupport {
 	@Override
 	public boolean onMessage(Message<?> message) {
 		if (!this.negotiated) {
-			Object payload = message.getPayload();
-			if (this.isServer()) {
-				if (payload.equals(hello)) {
-					try {
-						logger.debug(this.toString() + " sending " + this.world);
-						super.send(MessageBuilder.withPayload(world).build());
-						this.negotiated = true;
-						return true;
-					} catch (Exception e) {
-						throw new MessagingException("Negotiation error", e);
+			synchronized(this) {
+				if (!this.negotiated) {
+					Object payload = message.getPayload();
+					logger.debug(this.toString() + " received " + payload);
+					if (this.isServer()) {
+						if (payload.equals(hello)) {
+							try {
+								logger.debug(this.toString() + " sending " + this.world);
+								super.send(MessageBuilder.withPayload(world).build());
+								this.negotiated = true;
+								return true;
+							}
+							catch (Exception e) {
+								throw new MessagingException("Negotiation error", e);
+							}
+						}
+						else {
+							throw new MessagingException("Negotiation error, expected '" + hello +
+									     "' received '" + payload + "'");
+						}
+					}
+					else {
+						if (payload.equals(world)) {
+							this.negotiated = true;
+							this.negotiationSemaphore.release();
+						}
+						else {
+							throw new MessagingException("Negotiation error - expected '" + world +
+										"' received " + payload);
+						}
+						return true;
 					}
-				} else {
-					throw new MessagingException("Negotiation error, expected '" + hello +
-							     "' received '" + payload + "'");
 				}
-			} else {
-				logger.debug(this.toString() + " received " + payload);
-				if (payload.equals(world)) {
-					this.negotiated = true;
-					this.negotiationSemaphore.release();
-				} else {
-					throw new MessagingException("Negotiation error - expected '" + world +
-								"' received " + payload);
-				}
-				return true;
 			}
 		}
 		try {
 			return super.onMessage(message);
-		} finally {
+		}
+		finally {
 			// on the server side, we don't want to close if we are expecting a response
 			if (!(this.isServer() && this.hasRealSender()) && !this.pendingSend) {
 				this.checkDeferredClose();
@@ -113,7 +122,8 @@ public class HelloWorldInterceptor extends TcpConnectionInterceptorSupport {
 				}
 			}
 			super.send(message);
-		} finally {
+		}
+		finally {
 			this.pendingSend = false;
 			this.checkDeferredClose();
 		}