--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/test/hotspot/jtreg/vmTestbase/vm/gc/containers/CollectionContainer.java	Thu May 17 14:52:47 2018 -0700
@@ -0,0 +1,78 @@
+/*
+ * Copyright (c) 2010, 2018, Oracle and/or its affiliates. All rights reserved.
+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
+ *
+ * This code is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 only, as
+ * published by the Free Software Foundation.
+ *
+ * This code is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+ * version 2 for more details (a copy is included in the LICENSE file that
+ * accompanied this code).
+ *
+ * You should have received a copy of the GNU General Public License version
+ * 2 along with this work; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
+ * or visit www.oracle.com if you need additional information or have any
+ * questions.
+ */
+package vm.gc.containers;
+
+import java.util.Collection;
+import java.util.Iterator;
+import nsk.share.gc.gp.GarbageProducer;
+import nsk.share.gc.gp.MemoryStrategy;
+
+
+/*
+ * This class updates collection by removal of random elements
+ * via iterator and adding the same number of elements.
+ */
+class CollectionContainer extends TypicalContainer {
+
+    Collection collection;
+
+    public CollectionContainer(Collection collection, long maximumSize,
+            GarbageProducer garbageProducer, MemoryStrategy memoryStrategy, Speed speed) {
+        super(maximumSize, garbageProducer, memoryStrategy, speed);
+        this.collection = collection;
+    }
+
+    @Override
+    public void initialize() {
+        for (int i = 0; i < count; i++) {
+            if (!stresser.continueExecution()) {
+                return;
+            }
+            collection.add(garbageProducer.create(size));
+        }
+    }
+
+    @Override
+    public void update() {
+        Iterator iter = collection.iterator();
+        int i = 0;
+        while (iter.hasNext()) {
+            Object obj = iter.next();
+            if (i++ / 100 < speed.getValue()) {
+                if (!stresser.continueExecution()) {
+                    return;
+                }
+                iter.remove();
+                garbageProducer.validate(obj);
+            }
+        }
+        while (i != 0) {
+            if (i-- / 100 < speed.getValue()) {
+                if (!stresser.continueExecution()) {
+                    return;
+                }
+                collection.add(garbageProducer.create(size));
+            }
+        }
+    }
+}