1 files changed, 90 insertions, 0 deletions
diff --git a/plugins/org.eclipse.emf.cdo.common/src/org/eclipse/emf/cdo/common/util/PropertyChanged.java b/plugins/org.eclipse.emf.cdo.common/src/org/eclipse/emf/cdo/common/util/PropertyChanged.java
new file mode 100644
index 0000000000..332af6c9e8
--- /dev/null
+++ b/plugins/org.eclipse.emf.cdo.common/src/org/eclipse/emf/cdo/common/util/PropertyChanged.java
@@ -0,0 +1,90 @@
+/***************************************************************************
+ * Copyright (c) 2004 - 2008 Eike Stepper, Germany.
+ * All rights reserved. This program and the accompanying materials
+ * are made available under the terms of the Eclipse Public License v1.0
+ * which accompanies this distribution, and is available at
+ * http://www.eclipse.org/legal/epl-v10.html
+ * 
+ * Contributors:
+ *    Simon McDuff - initial API and implementation
+ **************************************************************************/
+package org.eclipse.emf.cdo.common.util;
+
+
+/**
+ * @author Simon McDuff
+ */
+public class PropertyChanged<T>
+{
+  Object notifier = new Object();
+  
+  T value;
+  
+  RuntimeException exception = null;
+  
+  public PropertyChanged(T value)
+  {
+    this.value = value;
+  }
+  
+  public T get()
+  {
+    return value;
+  }
+  
+  public void set(T newValue)
+  {
+    synchronized(notifier)
+    {
+      value = newValue;
+      notifier.notifyAll();
+    }
+  }
+  
+  public void setException(RuntimeException exception)
+  {
+    synchronized(notifier)
+    {
+      this.exception = exception;
+      notifier.notifyAll();
+    }
+  }
+  
+  public void acquire(Object accept, Object refuse)
+  {
+    acquire(accept, refuse, 0);
+  }
+  
+  public void acquire(Object accept, Object refuse, long timeout)
+  {
+    synchronized(notifier)
+    {      
+      while (!equalToOneElement(accept, refuse))
+      {
+        try
+        {
+          notifier.wait(timeout);
+        }
+        catch (InterruptedException ex)
+        {
+          Thread.currentThread().interrupt();
+        }
+      }
+    }
+  }
+  
+  private boolean equalToOneElement(Object accept, Object refuse)
+  {
+    if (this.exception != null)
+      throw this.exception;
+    
+    if (accept != null && accept.equals(value))
+       return true;
+    
+    if (refuse != null && refuse.equals(value))
+       throw new IllegalStateException();
+    
+     return false;
+  }
+  
+}