src/hotspot/share/jfr/recorder/service/jfrEventThrottler.hpp

/*
 * Copyright (c) 2020, Oracle and/or its affiliates. All rights reserved.
 * Copyright (c) 2020, Datadog, Inc. 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
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#ifndef SHARE_JFR_RECORDER_SERVICE_JFREVENTTHROTTLER_HPP
#define SHARE_JFR_RECORDER_SERVICE_JFREVENTTHROTTLER_HPP

#include "jfrfiles/jfrEventIds.hpp"
#include "jfr/support/jfrAdaptiveSampler.hpp"

class JfrEventThrottler : public JfrAdaptiveSampler {
  friend class JfrRecorder;
 private:
  JfrSamplerParams _last_params;
  int64_t _sample_size;
  int64_t _period_ms;
  double _sample_size_ewma;
  JfrEventId _event_id;
  bool _disabled;
  bool _update;

  static bool create();
  static void destroy();
  JfrEventThrottler(JfrEventId event_id);
  void configure(int64_t event_sample_size, int64_t period_ms);

  const JfrSamplerParams& update_params(const JfrSamplerWindow* expired);
  const JfrSamplerParams& next_window_params(const JfrSamplerWindow* expired);
  static JfrEventThrottler* for_event(JfrEventId event_id);

 public:
  static void configure(JfrEventId event_id, int64_t event_sample_size, int64_t period_ms);
  static bool accept(JfrEventId event_id, int64_t timestamp = 0);
};

#endif // SHARE_JFR_RECORDER_SERVICE_JFREVENTTHROTTLER_HPP