diff -r 4ebc2e2fb97c -r 71c04702a3d5 test/jdk/java/util/Collection/HotPotatoes.java
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/test/jdk/java/util/Collection/HotPotatoes.java	Tue Sep 12 19:03:39 2017 +0200
@@ -0,0 +1,106 @@
+/*
+ * Copyright (c) 2005, 2006, 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.
+ */
+
+/*
+ * @test
+ * @bug 6355660 6347106 6394004
+ * @summary methods taking concurrently mutating collection should work
+ * @author Martin Buchholz
+ */
+
+import java.lang.reflect.*;
+import java.util.*;
+import java.util.concurrent.*;
+
+@SuppressWarnings("unchecked")
+public class HotPotatoes {
+    private static void realMain(String[] args) throws Throwable {
+        testImplementation(Vector.class);
+        testImplementation(ArrayList.class);
+        testImplementation(PriorityQueue.class);
+        testImplementation(PriorityBlockingQueue.class);
+    }
+
+    private static void testImplementation(Class<? extends Collection> implClazz)
+        throws Throwable
+    {
+        testPotato(implClazz, Vector.class);
+        testPotato(implClazz, CopyOnWriteArrayList.class);
+
+        final Constructor<? extends Collection> constr
+            = implClazz.getConstructor(Collection.class);
+        final Collection<Object> coll
+            = constr.newInstance(Arrays.asList(new String[] {}));
+        coll.add(1);
+        equal(coll.toString(), "[1]");
+    }
+
+    private static void testPotato(Class<? extends Collection> implClazz,
+                                   Class<? extends List> argClazz)
+        throws Throwable
+    {
+        try {
+            System.out.printf("implClazz=%s, argClazz=%s\n",
+                              implClazz.getName(), argClazz.getName());
+            final int iterations = 100000;
+            final List<Integer> list = (List<Integer>) argClazz.newInstance();
+            final Integer one = Integer.valueOf(1);
+            final List<Integer> oneElementList = Collections.singletonList(one);
+            final Constructor<? extends Collection> constr
+                = implClazz.getConstructor(Collection.class);
+            final Thread t = new CheckedThread() { public void realRun() {
+                for (int i = 0; i < iterations; i++) {
+                    list.add(one);
+                    list.remove(one);
+                }}};
+            t.setDaemon(true);
+            t.start();
+
+            for (int i = 0; i < iterations; i++) {
+                Collection<?> coll = constr.newInstance(list);
+                Object[] elts = coll.toArray();
+                check(elts.length == 0 ||
+                      (elts.length == 1 && elts[0] == one));
+            }
+        } catch (Throwable t) { unexpected(t); }
+    }
+
+    //--------------------- Infrastructure ---------------------------
+    static volatile int passed = 0, failed = 0;
+    static void pass() {passed++;}
+    static void fail() {failed++; Thread.dumpStack();}
+    static void fail(String msg) {System.out.println(msg); fail();}
+    static void unexpected(Throwable t) {failed++; t.printStackTrace();}
+    static void check(boolean cond) {if (cond) pass(); else fail();}
+    static void equal(Object x, Object y) {
+        if (x == null ? y == null : x.equals(y)) pass();
+        else fail(x + " not equal to " + y);}
+    public static void main(String[] args) throws Throwable {
+        try {realMain(args);} catch (Throwable t) {unexpected(t);}
+        System.out.printf("%nPassed = %d, failed = %d%n%n", passed, failed);
+        if (failed > 0) throw new AssertionError("Some tests failed");}
+    private abstract static class CheckedThread extends Thread {
+        public abstract void realRun() throws Throwable;
+        public void run() {
+            try { realRun(); } catch (Throwable t) { unexpected(t); }}}
+}