Implement reference queuing in managed code.

This change adds a thread to the core library which receives a list of
references after a garbage collection and enqueues each element.  This
list is constructed by linking together the pendingNext field of cleared
references into a circular queue.

To support this change, the pendingNext field has been replaced by the
new zombie field for the purposes of providing a strongly reachable
location within a FinalizerReference class instance.

Change-Id: Id09133e44c850797e7f14c5471123a036d027c80

1 files changed, 3 insertions, 0 deletions

diff --git a/dalvik/src/main/java/dalvik/system/Zygote.java b/dalvik/src/main/java/dalvik/system/Zygote.java
index 791460b..1cdc52c 100644
--- a/dalvik/src/main/java/dalvik/system/Zygote.java
+++ b/dalvik/src/main/java/dalvik/system/Zygote.java
@@ -17,6 +17,7 @@
 package dalvik.system;
 
 import java.lang.FinalizerThread;
+import java.lang.ref.ReferenceQueueThread;
 
 /**
  * Provides access to the Dalvik "zygote" feature, which allows a VM instance to
@@ -48,10 +49,12 @@ public class Zygote {
     private Zygote() {}
 
     private static void preFork() {
+        ReferenceQueueThread.stopReferenceQueue();
         FinalizerThread.stopFinalizer();
     }
 
     private static void postFork() {
+        ReferenceQueueThread.startReferenceQueue();
         FinalizerThread.startFinalizer();
     }