--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/test/jdk/jdk/jfr/event/oldobject/TestLargeRootSet.java	Tue May 15 20:24:34 2018 +0200
@@ -0,0 +1,126 @@
+/*
+ * Copyright (c) 2015, 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.  Oracle designates this
+ * particular file as subject to the "Classpath" exception as provided
+ * by Oracle in the LICENSE file that accompanied this code.
+ *
+ * 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 jdk.jfr.event.oldobject;
+
+import java.util.ArrayList;
+import java.util.List;
+import java.util.concurrent.BrokenBarrierException;
+import java.util.concurrent.CyclicBarrier;
+
+import jdk.jfr.Recording;
+import jdk.jfr.consumer.RecordedClass;
+import jdk.jfr.consumer.RecordedEvent;
+import jdk.jfr.consumer.RecordedObject;
+import jdk.jfr.internal.test.WhiteBox;
+import jdk.test.lib.Asserts;
+import jdk.test.lib.jfr.EventNames;
+import jdk.test.lib.jfr.Events;
+
+/*
+ * @test
+ * @key jfr
+ * @requires vm.gc == "null"
+ * @library /test/lib /test/jdk
+ * @modules jdk.jfr/jdk.jfr.internal.test
+ * @run main/othervm -XX:TLABSize=2k -XX:-FastTLABRefill jdk.jfr.event.oldobject.TestLargeRootSet
+ */
+public class TestLargeRootSet {
+
+    private static final int THREAD_COUNT = 50;
+
+    private static class RootThread extends Thread {
+        private final CyclicBarrier barrier;
+        private int maxDepth = OldObjects.MIN_SIZE / THREAD_COUNT;
+
+        public List<StackObject[]> temporaries = new ArrayList<>(maxDepth);
+
+        RootThread(CyclicBarrier cb) {
+            this.barrier = cb;
+        }
+
+        public void run() {
+            buildRootObjects();
+        }
+
+        private void buildRootObjects() {
+            if (maxDepth-- > 0) {
+                // Allocate array to trigger sampling code path for interpreter / c1
+                StackObject[] stackObject = new StackObject[0];
+                temporaries.add(stackObject); // make sure object escapes
+                buildRootObjects();
+            } else {
+                temporaries.clear();
+                try {
+                    barrier.await(); // wait for gc
+                    barrier.await(); // wait for recording to be stopped
+                } catch (InterruptedException e) {
+                    System.err.println("Thread was unexpected interrupted: " + e.getMessage());
+                } catch (BrokenBarrierException e) {
+                    System.err.println("Unexpected barrier exception: " + e.getMessage());
+                }
+                return;
+            }
+        }
+    }
+
+    private static class StackObject {
+    }
+
+    public static void main(String[] args) throws Exception {
+        WhiteBox.setWriteAllObjectSamples(true);
+
+        List<RootThread> threads = new ArrayList<>();
+        try (Recording r = new Recording()) {
+            r.enable(EventNames.OldObjectSample).withStackTrace().with("cutoff", "infinity");
+            r.start();
+            CyclicBarrier cb = new CyclicBarrier(THREAD_COUNT + 1);
+            for (int i = 0; i < THREAD_COUNT; i++) {
+                RootThread t = new RootThread(cb);
+                t.start();
+                if (i % 10 == 0) {
+                    // Give threads some breathing room before starting next batch
+                    Thread.sleep(100);
+                }
+                threads.add(t);
+            }
+            cb.await();
+            System.gc();
+            r.stop();
+            cb.await();
+            List<RecordedEvent> events = Events.fromRecording(r);
+            Events.hasEvents(events);
+            for (RecordedEvent e : events) {
+                RecordedObject ro = e.getValue("object");
+                RecordedClass rc = ro.getValue("type");
+                System.out.println(rc.getName());
+                if (rc.getName().equals(StackObject[].class.getName())) {
+                    return; // ok
+                }
+            }
+            Asserts.fail("Could not find root object");
+        }
+    }
+}
+