Fixed bug in JobManager shutdown method

nephele/nephele-server/src/main/java/eu/stratosphere/nephele/jobmanager/JobManager.java

@@ -166,7 +166,9 @@ public class JobManager implements DeploymentManager, ExtendedManagementProtocol
 
  private final static int FAILURERETURNCODE = -1;
 
- private final AtomicBoolean isShutDown = new AtomicBoolean(false);
+ private final AtomicBoolean isShutdownInProgress = new AtomicBoolean(false);
+
+ private volatile boolean isShutDown = false;
 
  /**
  * Constructs a new job manager, starts its discovery service and its IPC service.
@@ -305,7 +307,7 @@ public void runTaskLoop() {
 
  public void shutdown() {
 
- if (this.isShutDown.compareAndSet(false, true)) {
+ if (!this.isShutdownInProgress.compareAndSet(false, true)) {
  return;
  }
 
@@ -355,7 +357,7 @@ public void shutdown() {
  this.scheduler.shutdown();
  }
 
- this.isShutDown.set(true);
+ this.isShutDown = true;
  LOG.debug("Shutdown of job manager completed");
  }
 
@@ -1089,7 +1091,7 @@ public void run() {
  */
  public boolean isShutDown() {
 
- return this.isShutDown.get();
+ return this.isShutDown;
  }
 
  /**