Consistent volatile access to running flag in Lifecycle implementations

Issue: SPR-16596
Issue: SPR-16488

(cherry picked from commit d4a8f76)

spring-tx/src/main/java/org/springframework/jca/endpoint/GenericMessageEndpointManager.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2016 the original author or authors.
+ * Copyright 2002-2018 the original author or authors.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -156,7 +156,7 @@ public class GenericMessageEndpointManager implements SmartLifecycle, Initializi
 
 	private int phase = Integer.MAX_VALUE;
 
-	private boolean running = false;
+	private volatile boolean running = false;
 
 	private final Object lifecycleMonitor = new Object();
 
@@ -318,9 +318,7 @@ public class GenericMessageEndpointManager implements SmartLifecycle, Initializi
 	 */
 	@Override
 	public boolean isRunning() {
-		synchronized (this.lifecycleMonitor) {
-			return this.running;
-		}
+		return this.running;
 	}
 
 	/**