src/share/classes/java/lang/ref/Finalizer.java

rev 670 : 8003335: Better handling of Finalizer thread
Reviewed-by: alanb, ahgross

@@ -36,13 +36,13 @@
     /* A native method that invokes an arbitrary object's finalize method is
        required since the finalize method is protected
      */
     static native void invokeFinalizeMethod(Object o) throws Throwable;
 
-    static private ReferenceQueue queue = new ReferenceQueue();
-    static private Finalizer unfinalized = null;
-    static private Object lock = new Object();
+    private static ReferenceQueue queue = new ReferenceQueue();
+    private static Finalizer unfinalized = null;
+    private static final Object lock = new Object();
 
     private Finalizer
         next = null,
         prev = null;
 

@@ -140,11 +140,15 @@
     }
 
     /* Called by Runtime.runFinalization() */
     static void runFinalization() {
         forkSecondaryFinalizer(new Runnable() {
+            private volatile boolean running;
             public void run() {
+                if (running)
+                    return;
+                running = true;
                 for (;;) {
                     Finalizer f = (Finalizer)queue.poll();
                     if (f == null) break;
                     f.runFinalizer();
                 }

@@ -153,11 +157,15 @@
     }
 
     /* Invoked by java.lang.Shutdown */
     static void runAllFinalizers() {
         forkSecondaryFinalizer(new Runnable() {
+            private volatile boolean running;
             public void run() {
+                if (running)
+                    return;
+                running = true;
                 for (;;) {
                     Finalizer f;
                     synchronized (lock) {
                         f = unfinalized;
                         if (f == null) break;

@@ -166,14 +174,18 @@
                     f.runFinalizer();
                 }}});
     }
 
     private static class FinalizerThread extends Thread {
+        private volatile boolean running;
         FinalizerThread(ThreadGroup g) {
             super(g, "Finalizer");
         }
         public void run() {
+            if (running)
+                return;
+            running = true;
             for (;;) {
                 try {
                     Finalizer f = (Finalizer)queue.remove();
                     f.runFinalizer();
                 } catch (InterruptedException x) {