--- a/src/jdk.jfr/share/classes/jdk/jfr/consumer/ChunkParser.java	Mon May 27 18:33:13 2019 +0200
+++ b/src/jdk.jfr/share/classes/jdk/jfr/consumer/ChunkParser.java	Mon May 27 22:59:18 2019 +0200
@@ -70,6 +70,7 @@
 
     public void setReuse(boolean resue) {
         this.reuse = resue;
+        updateParsers();
     }
 
     private ChunkParser(ChunkHeader header, ChunkParser previous, long pollInterval) throws IOException {
@@ -94,6 +95,7 @@
             parsers = previous.parsers;
             typeMap = previous.typeMap;
         }
+        updateParsers();
         constantLookups.forEach(c -> c.newPool());
         fillConstantPools(0);
         constantLookups.forEach(c -> c.getLatestPool().setResolving());

--- a/src/jdk.jfr/share/classes/jdk/jfr/consumer/EventStream.java	Mon May 27 18:33:13 2019 +0200
+++ b/src/jdk.jfr/share/classes/jdk/jfr/consumer/EventStream.java	Mon May 27 22:59:18 2019 +0200
@@ -59,8 +59,7 @@
      *         during reading
      */
     public static EventStream openFile(Path file) throws IOException {
-        throw new UnsupportedOperationException("Not yet implemented");
-        // return new EventFileStream(file);
+        return new EventFileStream(file);
     }
 
     /**

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/test/jdk/jdk/jfr/api/consumer/filestream/TestReuse.java	Mon May 27 22:59:18 2019 +0200
@@ -0,0 +1,104 @@
+/*
+ * 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.io.IOException;
+import java.nio.file.Files;
+import java.nio.file.Path;
+import java.util.HashMap;
+import java.util.IdentityHashMap;
+import java.util.Map;
+
+import jdk.jfr.Event;
+import jdk.jfr.Recording;
+import jdk.jfr.consumer.EventStream;
+import jdk.jfr.consumer.RecordedEvent;
+
+/**
+ * @test
+ * @summary Test EventStream::setReuse(...)
+ * @key jfr
+ * @requires vm.hasJFR
+ * @library /test/lib
+ * @run main/othervm jdk.jfr.api.consumer.filestream.TestReuse
+ */
+public class TestReuse {
+
+    static class ReuseEvent extends Event {
+    }
+
+    public static void main(String... args) throws Exception {
+        Path p = makeRecording();
+
+        testSetReuseTrue(p);
+        testSetReuseFalse(p);
+    }
+
+    private static void testSetReuseFalse(Path p) throws IOException {
+        Map<RecordedEvent, RecordedEvent> identity = new IdentityHashMap<>();
+        try (EventStream es = EventStream.openFile(p)) {
+            es.setReuse(false);
+            es.onEvent(e -> {
+                if (identity.containsKey(e)) {
+                    throw new Error("Unexpected reuse!");
+                }
+                identity.put(e,e);
+            });
+            es.start();
+        }
+    }
+
+    private static void testSetReuseTrue(Path p) throws IOException {
+        try (EventStream es = EventStream.openFile(p)) {
+            es.setReuse(true);
+            RecordedEvent[] events = new RecordedEvent[1];
+            es.onEvent(e -> {
+                if (events[0] == null) {
+                    events[0] = e;
+                } else {
+                    if (e != events[0]) {
+                        throw new Error("No reuse");
+                    }
+                }
+            });
+            es.start();
+        }
+    }
+
+    private static Path makeRecording() throws IOException {
+        try (Recording r = new Recording()) {
+            r.start();
+            for (int i = 0; i < 2_000_000; i++) {
+                ReuseEvent e = new ReuseEvent();
+                e.commit();
+            }
+            r.stop();
+            Path p = Files.createTempFile("recording", ".jfr");
+            r.dump(p);
+            return p;
+        }
+    }
+}