6948101: java/rmi/transport/pinLastArguments/PinLastArguments.java failing intermittently

Reviewed-by: dholmes, smarks
Contributed-by: NEric Wang <yiming.wang@oracle.com>

test/ProblemList.txt

@@ -271,9 +271,6 @@ java/nio/channels/Selector/OutOfBand.java                       macosx-all
 # 7140992
 java/rmi/server/Unreferenced/finiteGCLatency/FiniteGCLatency.java generic-all
 
-# 6948101
-java/rmi/transport/pinLastArguments/PinLastArguments.java	generic-all
-
 # 7146541
 java/rmi/transport/rapidExportUnexport/RapidExportUnexport.java	linux-all
 

test/java/rmi/transport/pinLastArguments/PinLastArguments.java

@@ -78,10 +78,15 @@ public class PinLastArguments {
         }
         impl = null;
 
-        System.gc();
-
-        if (ref.get() != null) {
-            throw new Error("TEST FAILED: impl not garbage collected");
+        // Might require multiple calls to System.gc() for weak-references
+        // processing to be complete. If the weak-reference is not cleared as
+        // expected we will hang here until timed out by the test harness.
+        while (true) {
+            System.gc();
+            Thread.sleep(20);
+            if (ref.get() == null) {
+                break;
+            }
         }
 
         System.err.println("TEST PASSED");