[391294] Provide a ShareableLifecycle

https://bugs.eclipse.org/bugs/show_bug.cgi?id=391294

3 files changed, 80 insertions, 4 deletions

diff --git a/plugins/org.eclipse.net4j.util/src/org/eclipse/net4j/util/container/Container.java b/plugins/org.eclipse.net4j.util/src/org/eclipse/net4j/util/container/Container.java
index 3dbf3a7d65..aa2b71f51a 100644
--- a/plugins/org.eclipse.net4j.util/src/org/eclipse/net4j/util/container/Container.java
+++ b/plugins/org.eclipse.net4j.util/src/org/eclipse/net4j/util/container/Container.java
@@ -13,7 +13,7 @@ package org.eclipse.net4j.util.container;
 import org.eclipse.net4j.util.container.IContainerDelta.Kind;
 import org.eclipse.net4j.util.event.IEvent;
 import org.eclipse.net4j.util.lifecycle.ILifecycle;
-import org.eclipse.net4j.util.lifecycle.Lifecycle;
+import org.eclipse.net4j.util.lifecycle.ShareableLifecycle;
 
 import java.util.List;
 
@@ -22,10 +22,19 @@ import java.util.List;
  *
  * @author Eike Stepper
  */
-public abstract class Container<E> extends Lifecycle implements IContainer<E>
+public abstract class Container<E> extends ShareableLifecycle implements IContainer<E>
 {
   public Container()
   {
+    this(false);
+  }
+
+  /**
+   * @since 3.3
+   */
+  public Container(boolean shareable)
+  {
+    super(shareable);
   }
 
   public boolean isEmpty()
diff --git a/plugins/org.eclipse.net4j.util/src/org/eclipse/net4j/util/lifecycle/Lifecycle.java b/plugins/org.eclipse.net4j.util/src/org/eclipse/net4j/util/lifecycle/Lifecycle.java
index 9d86ee9810..a63628d87d 100644
--- a/plugins/org.eclipse.net4j.util/src/org/eclipse/net4j/util/lifecycle/Lifecycle.java
+++ b/plugins/org.eclipse.net4j.util/src/org/eclipse/net4j/util/lifecycle/Lifecycle.java
@@ -51,7 +51,7 @@ public class Lifecycle extends Notifier implements ILifecycle, DeferrableActivat
   {
   }
 
-  public final void activate() throws LifecycleException
+  void internalActivate() throws LifecycleException
   {
     try
     {
@@ -105,7 +105,7 @@ public class Lifecycle extends Notifier implements ILifecycle, DeferrableActivat
     }
   }
 
-  public final Exception deactivate()
+  Exception internalDeactivate()
   {
     try
     {
@@ -157,6 +157,16 @@ public class Lifecycle extends Notifier implements ILifecycle, DeferrableActivat
     }
   }
 
+  public final void activate() throws LifecycleException
+  {
+    internalActivate();
+  }
+
+  public final Exception deactivate()
+  {
+    return internalDeactivate();
+  }
+
   /**
    * @since 3.0
    */
diff --git a/plugins/org.eclipse.net4j.util/src/org/eclipse/net4j/util/lifecycle/ShareableLifecycle.java b/plugins/org.eclipse.net4j.util/src/org/eclipse/net4j/util/lifecycle/ShareableLifecycle.java
new file mode 100644
index 0000000000..674d6df219
--- /dev/null
+++ b/plugins/org.eclipse.net4j.util/src/org/eclipse/net4j/util/lifecycle/ShareableLifecycle.java
@@ -0,0 +1,57 @@
+/*
+ * Copyright (c) 2004 - 2012 Eike Stepper (Berlin, Germany) and others.
+ * 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:
+ *    Eike Stepper - initial API and implementation
+ */
+package org.eclipse.net4j.util.lifecycle;
+
+import java.util.concurrent.atomic.AtomicInteger;
+
+/**
+ * A {@link Lifecycle lifecycle} entity with a reference count that can be {@link #activate() activated} multiple times.
+ *
+ * @author Eike Stepper
+ * @since 3.3
+ */
+public class ShareableLifecycle extends Lifecycle
+{
+  private AtomicInteger refCount;
+
+  public ShareableLifecycle()
+  {
+    this(true);
+  }
+
+  public ShareableLifecycle(boolean shared)
+  {
+    if (shared)
+    {
+      refCount = new AtomicInteger();
+    }
+  }
+
+  @Override
+  void internalActivate() throws LifecycleException
+  {
+    if (refCount == null || refCount.getAndIncrement() == 0)
+    {
+      super.internalActivate();
+    }
+  }
+
+  @Override
+  Exception internalDeactivate()
+  {
+    if (refCount == null || refCount.decrementAndGet() == 0)
+    {
+      return super.internalDeactivate();
+    }
+
+    return null;
+  }
+}