BUG-1120: expose AbstractRegistration state

[yangtools.git] / common / concepts / src / main / java / org / opendaylight / yangtools / concepts / AbstractRegistration.java

diff --git a/common/concepts/src/main/java/org/opendaylight/yangtools/concepts/AbstractRegistration.java b/common/concepts/src/main/java/org/opendaylight/yangtools/concepts/AbstractRegistration.java
index 50f19fc9e3ef596c56754909889b3d308a66e673..1a2c7f32f824cb9732cdaaa4068bd78378e5ac20 100644 (file)
--- a/common/concepts/src/main/java/org/opendaylight/yangtools/concepts/AbstractRegistration.java
+++ b/common/concepts/src/main/java/org/opendaylight/yangtools/concepts/AbstractRegistration.java
@@ -7,7 +7,7 @@
  */
 package org.opendaylight.yangtools.concepts;
 
-import java.util.concurrent.atomic.AtomicBoolean;
+import java.util.concurrent.atomic.AtomicIntegerFieldUpdater;
 
 /**
  * Utility registration handle. It is a convenience for register-style method
@@ -16,8 +16,10 @@ import java.util.concurrent.atomic.AtomicBoolean;
  * installed.
  */
 public abstract class AbstractRegistration implements AutoCloseable {
-    private AtomicBoolean closed = new AtomicBoolean();
-    
+    private static final AtomicIntegerFieldUpdater<AbstractRegistration> CLOSED_UPDATER =
+            AtomicIntegerFieldUpdater.newUpdater(AbstractRegistration.class, "closed");
+    private volatile int closed = 0;
+
     /**
      * Remove the state referenced by this registration. This method is
      * guaranteed to be called at most once. The referenced state must be
@@ -25,9 +27,19 @@ public abstract class AbstractRegistration implements AutoCloseable {
      */
     protected abstract void removeRegistration();
 
+    /**
+     * Query the state of this registration. Returns true if it was
+     * closed.
+     *
+     * @return true if the registration was closed, false otherwise.
+     */
+    protected final boolean isClosed() {
+        return CLOSED_UPDATER.get(this) != 0;
+    }
+
     @Override
     public final void close() {
-        if (closed.compareAndSet(false, true)) {
+        if (CLOSED_UPDATER.compareAndSet(this, 0, 1)) {
             removeRegistration();
         }
     }