--- /dev/null	2018-06-17 23:18:20.806999507 +0800
+++ new/test/lib/testlibrary/jdk/testlibrary/jfr/CommonHelper.java	2019-01-29 11:05:54.443615967 +0800
@@ -0,0 +1,116 @@
+/*
+ * Copyright (c) 2013, 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.testlibrary.jfr;
+
+import static jdk.testlibrary.Asserts.assertEquals;
+import static jdk.testlibrary.Asserts.fail;
+
+import java.io.IOException;
+import java.nio.file.Files;
+import java.nio.file.Path;
+import java.util.List;
+
+import jdk.jfr.Recording;
+import jdk.jfr.RecordingState;
+import jdk.jfr.consumer.RecordedEvent;
+import jdk.jfr.consumer.RecordingFile;
+import jdk.testlibrary.Asserts;
+
+
+/**
+ * Common helper class.
+ */
+public final class CommonHelper {
+
+    private static RecordedEvent timeStampCounterEvent;
+
+    public static void verifyException(VoidFunction f, String msg, Class<? extends Throwable> expectedException) throws Throwable {
+        try {
+            f.run();
+        } catch (Throwable t) {
+            if (expectedException.isAssignableFrom(t.getClass())) {
+                return;
+            }
+            t.printStackTrace();
+            assertEquals(t.getClass(), expectedException, "Wrong exception class");
+        }
+        fail("Missing Exception for: " + msg);
+    }
+
+    public static Recording verifyExists(long recId, List<Recording> recordings) {
+        for (Recording r : recordings) {
+            if (recId == r.getId()) {
+                return r;
+            }
+        }
+        Asserts.fail("Recording not found, id=" + recId);
+        return null;
+    }
+
+
+    public static void waitForRecordingState(Recording r, RecordingState expectedState) throws Exception {
+        while (r.getState() != expectedState) {
+            Thread.sleep(20);
+        }
+    }
+
+    public static void verifyRecordingState(Recording r, RecordingState expectedState) throws Exception {
+        assertEquals(expectedState, r.getState(), "Wrong state");
+    }
+
+    public static boolean hasFastTimeEnabled() throws Exception {
+        return getTimeStampCounterEvent().getValue("fastTimeEnabled");
+    }
+
+    private synchronized static RecordedEvent getTimeStampCounterEvent() throws IOException, Exception {
+        if (timeStampCounterEvent == null) {
+            try (Recording r = new Recording()) {
+                r.enable("com.oracle.jdk.CPUTimeStampCounter");
+                r.start();
+                r.stop();
+                Path p = Files.createTempFile("timestamo", ".jfr");
+                r.dump(p);
+                List<RecordedEvent> events = RecordingFile.readAllEvents(p);
+                Files.deleteIfExists(p);
+                if (events.isEmpty()) {
+                    throw new Exception("Could not locate CPUTimeStampCounter event");
+                }
+                timeStampCounterEvent = events.get(0);
+            }
+        }
+        return timeStampCounterEvent;
+    }
+
+    public static void waitForSystemCurrentMillisToChange() {
+        long t = System.currentTimeMillis();
+        while (t != System.currentTimeMillis()) {
+            try {
+                Thread.sleep(2);
+            } catch (InterruptedException e) {
+               throw new Error("Sleep interupted", e);
+            }
+        }
+    }
+}