From 52faf0446900cf169d5574fa470bfe4e71007011 Mon Sep 17 00:00:00 2001
From: Gary Russell <grussell@vmware.com>
Date: Tue, 3 Jan 2012 11:15:20 -0500
Subject: [PATCH] INT-2347 Update Channel Mappings Atomically

Ensure consistent state if channel map is replaced
dynamically.

Backport to 2.0.x.
---
 .../integration/router/AbstractMessageRouter.java     | 11 +++++++++--
 1 file changed, 9 insertions(+), 2 deletions(-)

diff --git a/spring-integration-core/src/main/java/org/springframework/integration/router/AbstractMessageRouter.java b/spring-integration-core/src/main/java/org/springframework/integration/router/AbstractMessageRouter.java
index 731ac17cbb..0507afe374 100644
--- a/spring-integration-core/src/main/java/org/springframework/integration/router/AbstractMessageRouter.java
+++ b/spring-integration-core/src/main/java/org/springframework/integration/router/AbstractMessageRouter.java
@@ -47,6 +47,7 @@ import org.springframework.util.StringUtils;
  * 
  * @author Mark Fisher
  * @author Oleg Zhurakousky
+ * @author Gary Russell
  */
 @ManagedResource
 public abstract class AbstractMessageRouter extends AbstractMessageHandler {
@@ -101,8 +102,14 @@ public abstract class AbstractMessageRouter extends AbstractMessageHandler {
 	 * @param channelIdentifierMap
 	 */
 	public void setChannelIdentifierMap(Map<String, String> channelIdentifierMap) {
-		this.channelIdentifierMap.clear();
-		this.channelIdentifierMap.putAll(channelIdentifierMap);
+		Map<String, String> oldChannelIdentifierMap = this.channelIdentifierMap;
+		Map<String, String> newChannelIdentifierMap = new ConcurrentHashMap<String, String>();
+		newChannelIdentifierMap.putAll(channelIdentifierMap);
+		this.channelIdentifierMap = newChannelIdentifierMap;
+		if (logger.isDebugEnabled()) {
+			logger.debug("Channel mappings:" + oldChannelIdentifierMap
+					+ " replaced with:" + newChannelIdentifierMap);
+		}
 	}
 
 	@ManagedOperation