--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/hotspot/share/jfr/recorder/service/jfrEvent.hpp	Tue May 15 20:24:34 2018 +0200
@@ -0,0 +1,214 @@
+/*
+ * Copyright (c) 2012, 2018, 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/jfrTime.hpp"
+#include "jfr/utilities/jfrTypes.hpp"
+#include "jfr/writers/jfrNativeEventWriter.hpp"
+#include "runtime/thread.hpp"
+#include "utilities/exceptions.hpp"
+#include "utilities/ticks.hpp"
+#ifdef ASSERT
+#include "utilities/bitMap.hpp"
+#endif
+
+#ifdef ASSERT
+class JfrEventVerifier {
+  template <typename>
+  friend class JfrEvent;
+ private:
+  // verification of event fields
+  BitMap::bm_word_t _verification_storage[1];
+  BitMapView _verification_bit_map;
+  bool _committed;
+
+  JfrEventVerifier();
+  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;
+  void set_committed();
+  void clear_committed();
+  bool committed() const;
+};
+#endif // ASSERT
+
+template <typename T>
+class JfrEvent {
+ private:
+  jlong _start_time;
+  jlong _end_time;
+  bool _started;
+
+ protected:
+  JfrEvent(EventStartTime timing=TIMED) : _start_time(0), _end_time(0), _started(false)
+#ifdef ASSERT
+  , _verifier()
+#endif
+  {
+    if (T::is_enabled()) {
+      _started = true;
+      if (TIMED == timing && !T::isInstant) {
+        set_starttime(JfrTicks::now());
+      }
+    }
+  }
+
+  void commit() {
+    if (!should_commit()) {
+      return;
+    }
+    assert(!_verifier.committed(), "event already committed");
+    if (_start_time == 0) {
+      set_starttime(JfrTicks::now());
+    } else if (_end_time == 0) {
+      set_endtime(JfrTicks::now());
+    }
+    if (should_write()) {
+      write_event();
+      DEBUG_ONLY(_verifier.set_committed();)
+    }
+  }
+
+ public:
+  void set_starttime(const JfrTicks& time) {
+    _start_time = time.value();
+  }
+
+  void set_endtime(const JfrTicks& time) {
+    _end_time = time.value();
+  }
+
+  void set_starttime(const Ticks& time) {
+    _start_time = JfrTime::is_ft_enabled() ? time.ft_value() : time.value();
+  }
+
+  void set_endtime(const Ticks& time) {
+    _end_time = JfrTime::is_ft_enabled() ? time.ft_value() : time.value();
+  }
+
+  static bool is_enabled() {
+    return JfrEventSetting::is_enabled(T::eventId);
+  }
+
+  static bool is_stacktrace_enabled() {
+    return JfrEventSetting::has_stacktrace(T::eventId);
+  }
+
+  static JfrEventId id() {
+    return T::eventId;
+  }
+
+  static bool is_instant() {
+    return T::isInstant;
+  }
+
+  static bool is_requestable() {
+    return T::isRequestable;
+  }
+
+  static bool has_thread() {
+    return T::hasThread;
+  }
+
+  static bool has_stacktrace() {
+    return T::hasStackTrace;
+  }
+
+  bool should_commit() {
+    return _started;
+  }
+
+ private:
+  bool should_write() {
+    if (T::isInstant || T::isRequestable || T::hasCutoff) {
+      return true;
+    }
+    return (_end_time - _start_time) >= JfrEventSetting::threshold(T::eventId);
+  }
+
+  void write_event() {
+    DEBUG_ONLY(assert_precondition();)
+    Thread* const event_thread = Thread::current();
+    JfrThreadLocal* const tl = event_thread->jfr_thread_local();
+    JfrBuffer* const buffer = tl->native_buffer();
+    if (buffer == NULL) {
+      // most likely a pending OOM
+      return;
+    }
+    JfrNativeEventWriter writer(buffer, event_thread);
+    writer.write<u8>(T::eventId);
+    assert(_start_time != 0, "invariant");
+    writer.write(_start_time);
+    if (!(T::isInstant || T::isRequestable) || T::hasCutoff) {
+      assert(_end_time != 0, "invariant");
+      writer.write(_end_time - _start_time);
+    }
+    if (T::hasThread) {
+      writer.write(tl->thread_id());
+    }
+    if (T::hasStackTrace) {
+      if (is_stacktrace_enabled()) {
+        if (tl->has_cached_stack_trace()) {
+          writer.write(tl->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
+  JfrEventVerifier _verifier;
+
+  void assert_precondition() {
+    assert(T::eventId >= (JfrEventId)NUM_RESERVED_EVENTS, "event id underflow invariant");
+    assert(T::eventId < MaxJfrEventId, "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
+    _verifier.clear_committed();
+  }
+
+  bool verify_field_bit(size_t field_idx) const {
+    return _verifier.verify_field_bit(field_idx);
+  }
+#endif // ASSERT
+};
+
+#endif // SHARE_VM_JFR_RECORDER_SERVICE_JFREVENT_HPP