/*

 * 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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#include "gc/shared/generation.hpp"

#include "gc/shared/generationCounters.hpp"

#include "runtime/perfData.hpp"

#include "utilities/macros.hpp"

// A GSpaceCounter is a holder class for performance counters

// that track a space;

class GSpaceCounters: public CHeapObj<mtGC> {

  friend class VMStructs;

 private:

  PerfVariable*      _capacity;

  PerfVariable*      _used;

  // Constant PerfData types don't need to retain a reference.

  // However, it's a good idea to document them here.

  // PerfConstant*     _size;

  Generation*       _gen;

  char*             _name_space;

 public:

  GSpaceCounters(const char* name, int ordinal, size_t max_size, Generation* g,

                 GenerationCounters* gc, bool sampled=true);

  ~GSpaceCounters();

  inline void update_capacity() {

    _capacity->set_value(_gen->capacity());

  }

  inline void update_used() {

    _used->set_value(_gen->used());

  }

  // special version of update_used() to allow the used value to be

  // passed as a parameter. This method can can be used in cases were

  // the  utilization is already known and/or when the _gen->used()

  // method is known to be expensive and we want to avoid unnecessary

  // calls to it.

  //

  inline void update_used(size_t used) {

    _used->set_value(used);

  }

  inline void inc_used(size_t size) {

    _used->inc(size);

  }

  debug_only(

    // for security reasons, we do not allow arbitrary reads from

    // the counters as they may live in shared memory.

    jlong used() {

      return _used->get_value();

    }

    jlong capacity() {

      return _used->get_value();

    }

  )

  inline void update_all() {

    update_used();

    update_capacity();

  }

  const char* name_space() const        { return _name_space; }

};

class GenerationUsedHelper : public PerfLongSampleHelper {

  private:

    Generation* _gen;

  public:

    GenerationUsedHelper(Generation* g) : _gen(g) { }

    inline jlong take_sample() {

      return _gen->used();

    }

};