--- /dev/null	2019-01-28 17:47:38.000000000 +0800
+++ new/src/share/vm/jfr/recorder/service/jfrEvent.hpp	2019-01-28 17:47:37.000000000 +0800
@@ -0,0 +1,152 @@
+/*
+ * Copyright (c) 2012, 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.
+ *
+ * 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.
+ *
+ */
+
+#ifndef SHARE_VM_JFR_RECORDER_SERVICE_JFREVENT_HPP
+#define SHARE_VM_JFR_RECORDER_SERVICE_JFREVENT_HPP
+
+#include "jfr/recorder/jfrEventSetting.inline.hpp"
+#include "jfr/recorder/stacktrace/jfrStackTraceRepository.hpp"
+#include "jfr/utilities/jfrTraceTime.hpp"
+#include "jfr/writers/jfrNativeEventWriter.hpp"
+#include "runtime/thread.hpp"
+#include "trace/traceEvent.hpp"
+#include "utilities/ticks.hpp"
+#ifdef ASSERT
+#include "utilities/bitMap.hpp"
+#endif
+
+#ifdef ASSERT
+class JfrTraceEventVerifier {
+  template <typename>
+  friend class JfrTraceEvent;
+ private:
+  // verification of event fields
+  BitMap::bm_word_t _verification_storage[1];
+  BitMap _verification_bit_map;
+
+  JfrTraceEventVerifier();
+  void check(BitMap::idx_t field_idx) const;
+  void set_field_bit(size_t field_idx);
+  bool verify_field_bit(size_t field_idx) const;
+};
+
+#endif // ASSERT
+
+template <typename T>
+class JfrTraceEvent : public TraceEvent<T> {
+ protected:
+  JfrTraceEvent(EventStartTime timing=TIMED) : TraceEvent<T>(timing)
+#ifdef ASSERT
+   , _verifier()
+#endif
+   { }
+
+ public:
+  void set_starttime(const JfrTraceTime& time) {
+    this->_startTime = time.value();
+  }
+
+  void set_endtime(const JfrTraceTime& time) {
+    this->_endTime = time.value();
+  }
+
+  void set_starttime(const Ticks& time) {
+    this->_startTime = JfrTraceTime::is_ft_enabled() ? time.ft_value() : time.value();
+  }
+
+  void set_endtime(const Ticks& time) {
+    this->_endTime = JfrTraceTime::is_ft_enabled() ? time.ft_value() : time.value();
+  }
+
+ private:
+  bool should_write() {
+    if (T::isInstant || T::isRequestable || T::hasCutoff) {
+      return true;
+    }
+    return (this->_endTime - this->_startTime) >= JfrEventSetting::threshold(T::eventId);
+  }
+
+  void writeEvent() {
+    DEBUG_ONLY(assert_precondition();)
+    Thread* const event_thread = Thread::current();
+    JfrThreadData* const trace_data = event_thread->trace_data();
+    JfrBuffer* const buffer = trace_data->native_buffer();
+    if (buffer == NULL) {
+      // most likely a pending OOM
+      return;
+    }
+    JfrNativeEventWriter writer(buffer, event_thread);
+    writer.write<u8>(T::eventId);
+    assert(this->_startTime != 0, "invariant");
+    writer.write(this->_startTime);
+    if (!(T::isInstant || T::isRequestable) || T::hasCutoff) {
+      assert(this->_endTime != 0, "invariant");
+      writer.write(this->_endTime - this->_startTime);
+    }
+    if (T::hasThread) {
+      writer.write(trace_data->thread_id());
+    }
+    if (T::hasStackTrace) {
+      if (JfrEventSetting::has_stacktrace(T::eventId)) {
+        if (trace_data->has_cached_stack_trace()) {
+          writer.write(trace_data->cached_stack_trace_id());
+        } else {
+          writer.write(JfrStackTraceRepository::record(event_thread));
+        }
+      } else {
+        writer.write<traceid>(0);
+      }
+    }
+    // payload
+    static_cast<T*>(this)->writeData(writer);
+  }
+
+#ifdef ASSERT
+ private:
+  // verification of event fields
+  JfrTraceEventVerifier _verifier;
+
+  void assert_precondition() {
+    assert(T::eventId >= (TraceEventId)NUM_RESERVED_EVENTS, "event id underflow invariant");
+    assert(T::eventId < MaxTraceEventId, "event id overflow invariant");
+    DEBUG_ONLY(static_cast<T*>(this)->verify());
+  }
+
+ protected:
+  void set_field_bit(size_t field_idx) {
+    _verifier.set_field_bit(field_idx);
+    // it is ok to reuse an already committed event
+    // granted you provide new informational content
+    this->_committed = false;
+  }
+  bool verify_field_bit(size_t field_idx) const {
+    return _verifier.verify_field_bit(field_idx);
+  }
+#endif // ASSERT
+
+  template <typename>
+  friend class TraceEvent;
+};
+
+#endif // SHARE_VM_JFR_RECORDER_SERVICE_JFREVENT_HPP