--- /dev/null	2018-06-17 23:18:20.806999507 +0800
+++ new/src/share/classes/jdk/jfr/internal/JVMUpcalls.java	2019-01-29 10:59:32.051778960 +0800
@@ -0,0 +1,143 @@
+/*
+ * Copyright (c) 2016, 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.internal;
+
+import java.lang.reflect.Modifier;
+
+import jdk.jfr.Event;
+import jdk.jfr.internal.handlers.EventHandler;
+import jdk.jfr.internal.instrument.JDKEvents;
+
+/**
+ * All upcalls from the JVM should go through this class.
+ *
+ */
+// Called by native
+final class JVMUpcalls {
+    /**
+     * Called by the JVM when a retransform happens on a tagged class
+     *
+     * @param traceId
+     *            Id of the class
+     * @param dummy
+     *            (not used but needed since invoke infrastructure in native
+     *            uses same signature bytesForEagerInstrumentation)
+     * @param clazz
+     *            class being retransformed
+     * @param oldBytes
+     *            byte code
+     * @return byte code to use
+     * @throws Throwable
+     */
+    static byte[] onRetransform(long traceId, boolean dummy, Class<?> clazz, byte[] oldBytes) throws Throwable {
+        try {
+            if (Event.class.isAssignableFrom(clazz) && !Modifier.isAbstract(clazz.getModifiers())) {
+                EventHandler handler = Utils.getHandler(clazz.asSubclass(Event.class));
+                if (handler == null) {
+                    Logger.log(LogTag.JFR_SYSTEM, LogLevel.INFO, "No event handler found for " + clazz.getName() + ". Ignoring instrumentation request.");
+                    // Probably triggered by some other agent
+                    return oldBytes;
+                }
+                Logger.log(LogTag.JFR_SYSTEM, LogLevel.INFO, "Adding instrumentation to event class " + clazz.getName() + " using retransform");
+                EventInstrumentation ei = new EventInstrumentation(clazz.getSuperclass(), oldBytes, traceId);
+                byte[] bytes = ei.buildInstrumented();
+                ASMToolkit.logASM(clazz.getName(), bytes);
+                return bytes;
+            }
+            return JDKEvents.retransformCallback(clazz, oldBytes);
+        } catch (Throwable t) {
+            Logger.log(LogTag.JFR_SYSTEM, LogLevel.WARN, "Unexpected error when adding instrumentation to event class " + clazz.getName());
+        }
+        return oldBytes;
+
+    }
+
+    /**
+     * Called by the JVM when requested to do an "eager" instrumentation. Would
+     * normally happen when JVMTI retransform capabilities are not available.
+     *
+     * @param traceId
+     *            Id of the class
+     * @param forceInstrumentation
+     *            add instrumentation regardless if event is enabled or not.
+     * @param superClazz
+     *            the super class of the class being processed
+     * @param oldBytes
+     *            byte code
+     * @return byte code to use
+     * @throws Throwable
+     */
+    static byte[] bytesForEagerInstrumentation(long traceId, boolean forceInstrumentation, Class<?> superClass, byte[] oldBytes) throws Throwable {
+        if (JVMSupport.isNotAvailable()) {
+            return oldBytes;
+        }
+        String eventName = "<Unknown>";
+        try {
+            EventInstrumentation ei = new EventInstrumentation(superClass, oldBytes, traceId);
+            eventName = ei.getEventName();
+            if (!forceInstrumentation) {
+                // Assume we are recording
+                MetadataRepository mr = MetadataRepository.getInstance();
+                // No need to generate bytecode if:
+                // 1) Event class is disabled, and there is not an external configuration that overrides.
+                // 2) Event class has @Registered(false)
+                if (!mr.isEnabled(ei.getEventName()) && !ei.isEnabled() || !ei.isRegistered()) {
+                    Logger.log(LogTag.JFR_SYSTEM, LogLevel.INFO, "Skipping instrumentation for event type " + eventName + " since event was disabled on class load");
+                    return oldBytes;
+                }
+            }
+            // Corner case when we are forced to generate bytecode. We can't reference the event
+            // handler in #isEnabled() before event class has been registered, so we add a
+            // guard against a null reference.
+            ei.setGuardHandler(true);
+            Logger.log(LogTag.JFR_SYSTEM, LogLevel.INFO, "Adding " + (forceInstrumentation ? "forced " : "") + "instrumentation for event type " + eventName + " during initial class load");
+            EventHandlerCreator eh = new EventHandlerCreator(traceId, ei.getSettingInfos(), ei.getFieldInfos());
+            // Handler class must be loaded before instrumented event class can
+            // be used
+            eh.makeEventHandlerClass();
+            byte[] bytes = ei.buildInstrumented();
+            ASMToolkit.logASM(ei.getClassName() + "(" + traceId + ")", bytes);
+            return bytes;
+        } catch (Throwable t) {
+            Logger.log(LogTag.JFR_SYSTEM, LogLevel.WARN, "Unexpected error when adding instrumentation for event type " + eventName);
+            return oldBytes;
+        }
+    }
+
+    /**
+     * Called by the JVM to create the recorder thread.
+     *
+     * @param systemThreadGroup
+     *            the system thread group
+     *
+     * @param contextClassLoader
+     *            the context class loader.
+     *
+     * @return a new thread
+     */
+    static Thread createRecorderThread(ThreadGroup systemThreadGroup, ClassLoader contextClassLoader) {
+        return SecuritySupport.createRecorderThread(systemThreadGroup, contextClassLoader);
+    }
+}