3 files changed, 47 insertions, 11 deletions

diff --git a/libart/src/main/java/dalvik/system/VMRuntime.java b/libart/src/main/java/dalvik/system/VMRuntime.java
index b885ed2..aa3f154 100644
--- a/libart/src/main/java/dalvik/system/VMRuntime.java
+++ b/libart/src/main/java/dalvik/system/VMRuntime.java
@@ -16,6 +16,7 @@
 
 package dalvik.system;
 
+import java.lang.ref.FinalizerReference;
 import java.util.HashMap;
 import java.util.Map;
 
@@ -301,6 +302,30 @@ public final class VMRuntime {
      */
     public native void registerNativeFree(int bytes);
 
+    /**
+     * Wait for objects to be finalized.
+     *
+     * If finalization takes longer than timeout, then the function returns before all objects are
+     * finalized.
+     *
+     * @param timeout
+     *            timeout in nanoseconds of the maximum time to wait until all pending finalizers
+     *            are run. If timeout is 0, then there is no timeout. Note that the timeout does
+     *            not stop the finalization process, it merely stops the wait.
+     *
+     * @see #Runtime.runFinalization()
+     * @see #wait(long,int)
+     */
+    public static void runFinalization(long timeout) {
+        try {
+            FinalizerReference.finalizeAllEnqueued(timeout);
+        } catch (InterruptedException e) {
+            // Interrupt the current thread without actually throwing the InterruptionException
+            // for the caller.
+            Thread.currentThread().interrupt();
+        }
+    }
+
     public native void requestConcurrentGC();
     public native void concurrentGC();
     public native void requestHeapTrim();
diff --git a/luni/src/main/java/java/lang/Runtime.java b/luni/src/main/java/java/lang/Runtime.java
index 3ddacf7..ad549f2 100644
--- a/luni/src/main/java/java/lang/Runtime.java
+++ b/luni/src/main/java/java/lang/Runtime.java
@@ -34,6 +34,7 @@ package java.lang;
 
 import dalvik.system.BaseDexClassLoader;
 import dalvik.system.VMDebug;
+import dalvik.system.VMRuntime;
 import dalvik.system.VMStack;
 import java.io.File;
 import java.io.IOException;
@@ -438,20 +439,17 @@ public class Runtime {
             String ldLibraryPath, String dexPath);
 
     /**
-     * Provides a hint to the VM that it would be useful to attempt
+     * Provides a hint to the runtime that it would be useful to attempt
      * to perform any outstanding object finalization.
      */
     public void runFinalization() {
-        try {
-            FinalizerReference.finalizeAllEnqueued();
-        } catch (InterruptedException e) {
-            Thread.currentThread().interrupt();
-        }
+        // 0 for no timeout.
+        VMRuntime.runFinalization(0);
     }
 
     /**
      * Sets the flag that indicates whether all objects are finalized when the
-     * VM is about to exit. Note that all finalization which occurs
+     * runtime is about to exit. Note that all finalization which occurs
      * when the system is exiting is performed after all running threads have
      * been terminated.
      *
diff --git a/luni/src/main/java/java/lang/ref/FinalizerReference.java b/luni/src/main/java/java/lang/ref/FinalizerReference.java
index 5416a80..02cfa01 100644
--- a/luni/src/main/java/java/lang/ref/FinalizerReference.java
+++ b/luni/src/main/java/java/lang/ref/FinalizerReference.java
@@ -82,7 +82,7 @@ public final class FinalizerReference<T> extends Reference<T> {
     /**
      * Waits for all currently-enqueued references to be finalized.
      */
-    public static void finalizeAllEnqueued() throws InterruptedException {
+    public static void finalizeAllEnqueued(long timeout) throws InterruptedException {
         // Alloate a new sentinel, this creates a FinalizerReference.
         Sentinel sentinel;
         // Keep looping until we safely enqueue our sentinel FinalizerReference.
@@ -91,7 +91,7 @@ public final class FinalizerReference<T> extends Reference<T> {
         do {
             sentinel = new Sentinel();
         } while (!enqueueSentinelReference(sentinel));
-        sentinel.awaitFinalization();
+        sentinel.awaitFinalization(timeout);
     }
 
     private static boolean enqueueSentinelReference(Sentinel sentinel) {
@@ -144,9 +144,22 @@ public final class FinalizerReference<T> extends Reference<T> {
             notifyAll();
         }
 
-        synchronized void awaitFinalization() throws InterruptedException {
+        synchronized void awaitFinalization(long timeout) throws InterruptedException {
+            final long startTime = System.nanoTime();
+            final long endTime = startTime + timeout;
             while (!finalized) {
-                wait();
+                // 0 signifies no timeout.
+                if (timeout != 0) {
+                    final long currentTime = System.nanoTime();
+                    if (currentTime >= endTime) {
+                        break;
+                    } else {
+                        final long deltaTime = endTime - currentTime;
+                        wait(deltaTime / 1000000, (int)(deltaTime % 1000000));
+                    }
+                } else {
+                    wait();
+                }
             }
         }
     }