diff -r 2c3cc4b01880 -r c16ac7a2eba4 test/jdk/jdk/jfr/api/consumer/filestream/TestOrdered.java
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/test/jdk/jdk/jfr/api/consumer/filestream/TestOrdered.java	Wed Oct 30 19:43:52 2019 +0100
@@ -0,0 +1,152 @@
+/*
+ * Copyright (c) 2019, 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.api.consumer.filestream;
+
+import java.nio.file.Files;
+import java.nio.file.Path;
+import java.time.Instant;
+import java.util.ArrayList;
+import java.util.List;
+import java.util.concurrent.CyclicBarrier;
+import java.util.concurrent.atomic.AtomicBoolean;
+import java.util.concurrent.atomic.AtomicReference;
+
+import jdk.jfr.Event;
+import jdk.jfr.Recording;
+import jdk.jfr.consumer.EventStream;
+
+/**
+ * @test
+ * @summary Test EventStream::setOrdered(...)
+ * @key jfr
+ * @requires vm.hasJFR
+ * @library /test/lib
+ * @run main/othervm jdk.jfr.api.consumer.filestream.TestOrdered
+ */
+public class TestOrdered {
+
+    static class OrderedEvent extends Event {
+    }
+
+    static class Emitter extends Thread {
+        private final CyclicBarrier barrier;
+
+        public Emitter(CyclicBarrier barrier) {
+            this.barrier = barrier;
+        }
+
+        @Override
+        public void run() {
+            OrderedEvent e1 = new OrderedEvent();
+            e1.commit();
+            try {
+                barrier.await();
+            } catch (Exception e) {
+                e.printStackTrace();
+                throw new Error("Unexpected exception in barrier");
+            }
+            OrderedEvent e2 = new OrderedEvent();
+            e2.commit();
+        }
+    }
+
+    private static final int THREAD_COUNT = 4;
+    private static final boolean[] BOOLEAN_STATES = { false, true };
+
+    public static void main(String... args) throws Exception {
+        Path p = makeUnorderedRecording();
+
+        testSetOrderedTrue(p);
+        testSetOrderedFalse(p);
+    }
+
+    private static void testSetOrderedTrue(Path p) throws Exception {
+        for (boolean reuse : BOOLEAN_STATES) {
+            AtomicReference<Instant> timestamp = new AtomicReference<>(Instant.MIN);
+            try (EventStream es = EventStream.openFile(p)) {
+                es.setReuse(reuse);
+                es.setOrdered(true);
+                es.onEvent(e -> {
+                    Instant endTime = e.getEndTime();
+                    if (endTime.isBefore(timestamp.get())) {
+                        throw new Error("Events are not ordered! Reuse = " + reuse);
+                    }
+                    timestamp.set(endTime);
+                });
+                es.start();
+            }
+        }
+    }
+
+    private static void testSetOrderedFalse(Path p) throws Exception {
+        for (boolean reuse : BOOLEAN_STATES) {
+            AtomicReference<Instant> timestamp = new AtomicReference<>(Instant.MIN);
+            AtomicBoolean unoreded = new AtomicBoolean(false);
+            try (EventStream es = EventStream.openFile(p)) {
+                es.setReuse(reuse);
+                es.setOrdered(false);
+                es.onEvent(e -> {
+                    Instant endTime = e.getEndTime();
+                    if (endTime.isBefore(timestamp.get())) {
+                        unoreded.set(true);
+                        es.close();
+                    }
+                    timestamp.set(endTime);
+                });
+                es.start();
+                if (!unoreded.get()) {
+                    throw new Exception("Expected at least some events to be out of order! Reuse = " + reuse);
+                }
+            }
+        }
+    }
+
+    private static Path makeUnorderedRecording() throws Exception {
+        CyclicBarrier barrier = new CyclicBarrier(THREAD_COUNT + 1);
+
+        try (Recording r = new Recording()) {
+            r.start();
+            List<Emitter> emitters = new ArrayList<>();
+            for (int i = 0; i < THREAD_COUNT; i++) {
+                Emitter e = new Emitter(barrier);
+                e.start();
+                emitters.add(e);
+            }
+            // Thread buffers should now have one event each
+            barrier.await();
+            // Add another event to each thread buffer, so
+            // events are bound to come out of order when they
+            // are flushed
+            for (Emitter e : emitters) {
+                e.join();
+            }
+            r.stop();
+            Path p = Files.createTempFile("recording", ".jfr");
+            r.dump(p);
+            return p;
+        }
+    }
+}