/*

 * Copyright (c) 2001, 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_RUNTIME_STATSAMPLER_HPP

#define SHARE_RUNTIME_STATSAMPLER_HPP

#include "runtime/perfData.hpp"

#include "runtime/task.hpp"

class StatSamplerTask;

/*

 * The StatSampler class is responsible for periodically updating

 * sampled PerfData instances and writing the sampled values to the

 * PerfData memory region.

 *

 * In addition it is also responsible for providing a home for

 * PerfData instances that otherwise have no better home.

 */

class StatSampler : AllStatic {

  friend class StatSamplerTask;

  private:

    static StatSamplerTask* _task;

    static PerfDataList* _sampled;

    static void collect_sample();

    static void create_misc_perfdata();

    static void create_sampled_perfdata();

    static void sample_data(PerfDataList* list);

    static const char* get_system_property(const char* name, TRAPS);

    static void create_system_property_instrumentation(TRAPS);

  public:

    // Start/stop the sampler

    static void engage();

    static void disengage();

    static bool is_active() { return _task != NULL; }

    static void initialize();

    static void destroy();

};

#endif // SHARE_RUNTIME_STATSAMPLER_HPP