--- old/test/hotspot/jtreg/vmTestbase/nsk/jdi/ReferenceType/instances/instances003/instances003.java	2018-11-07 16:35:13.000000000 -0800
+++ new/test/hotspot/jtreg/vmTestbase/nsk/jdi/ReferenceType/instances/instances003/instances003.java	2018-11-07 16:35:12.000000000 -0800
@@ -62,6 +62,7 @@
 import java.io.PrintStream;
 import java.util.*;
 
+import com.sun.jdi.ObjectCollectedException;
 import com.sun.jdi.ObjectReference;
 import com.sun.jdi.ReferenceType;
 
@@ -122,9 +123,10 @@
 
         // create temporary strong references to prevent the weakly referred instances being GCed
         // during the time between creating them and disabling collection on them
+        boolean useTempStrongReference = needTempStongReference(referrerType);
         pipe.println(HeapwalkingDebuggee.COMMAND_CREATE_INSTANCES + ":" + className + ":" + createInstanceCount +
-            ":" + referrerCount + ":" + referrerType +
-            (referrerType.equals(ObjectInstancesManager.WEAK_REFERENCE) ? "|" + ObjectInstancesManager.STRONG_REFERENCE : ""));
+                ":" + referrerCount + ":" + referrerType +
+                (useTempStrongReference ? "|" + ObjectInstancesManager.STRONG_REFERENCE : ""));
 
         // Note! This test is broken, in the sense that it incorrectly assumes
         // that no GC can happen before it walks the heap. In practice, it seems
@@ -135,14 +137,24 @@
         checkDebugeeAnswer_instanceCounts(className, createInstanceCount, objectsToFilter);
 
         ReferenceType referenceType = debuggee.classByName(className);
-        List<ObjectReference> instances = HeapwalkingDebugger.filterObjectReferrence(objectsToFilter, referenceType.instances(0));
+        List<ObjectReference> allInstances = HeapwalkingDebugger.filterObjectReferrence(objectsToFilter, referenceType.instances(0));
 
-        for (ObjectReference or : instances) {
-            or.disableCollection();
+        // There are potentially other non-test Java threads allocating objects and triggering GC's.
+        // We need to call disableCollection() on each object returned by referenceType.instances()
+        // to deal with the case when GC was triggered. Otherwise, these objects can
+        // be potentially collected.
+        List<ObjectReference> instances = new LinkedList<>();
+        for (ObjectReference objRef : allInstances) {
+            try {
+                objRef.disableCollection();
+                instances.add(objRef);
+            } catch (ObjectCollectedException ex) {
+                // skip this references
+            }
         }
 
         // remove the temporary strong references so the weak references can be properly tested
-        if (referrerType.equals(ObjectInstancesManager.WEAK_REFERENCE)) {
+        if (useTempStrongReference) {
             pipe.println(HeapwalkingDebuggee.COMMAND_DELETE_REFERRERS + ":" + className + ":" + referrerCount + ":" + ObjectInstancesManager.STRONG_REFERENCE);
             if (!isDebuggeeReady()) {
                 return;
@@ -157,6 +169,7 @@
             instances.get(i).enableCollection();
         }
 
+
         pipe.println(HeapwalkingDebuggee.COMMAND_DELETE_INSTANCES + ":" + className + ":" + createInstanceCount);
 
         if (!isDebuggeeReady())
@@ -183,4 +196,13 @@
                 testClass(className, referenceType);
         }
     }
+
+
+    private static boolean needTempStongReference(String referenceType) {
+        return ObjectInstancesManager.WEAK_REFERENCE.equals(referenceType) ||
+                ObjectInstancesManager.JNI_WEAK_REFERENCE.equals(referenceType) ||
+                ObjectInstancesManager.PHANTOM_REFERENCE.equals(referenceType) ||
+                ObjectInstancesManager.SOFT_REFERENCE.equals(referenceType);
+
+    }
 }