/*

 * 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

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 */

#include "memory/heap.hpp"

#include "oops/oop.hpp"

#include "services/memoryUsage.hpp"

#include "utilities/macros.hpp"

// A memory pool represents the memory area that the VM manages.

// The Java virtual machine has at least one memory pool

// and it may create or remove memory pools during execution.

// A memory pool can belong to the heap or the non-heap memory.

// A Java virtual machine may also have memory pools belonging to

// both heap and non-heap memory.

// Forward declaration

class MemoryManager;

class SensorInfo;

class ThresholdSupport;

class MemoryPool : public CHeapObj<mtInternal> {

  friend class MemoryManager;

 public:

  enum PoolType {

    Heap    = 1,

    NonHeap = 2

  };

 private:

  enum {

    max_num_managers = 5

  };

  // We could make some of the following as performance counters

  // for external monitoring.

  const char*      _name;

  PoolType         _type;

  size_t           _initial_size;

  size_t           _max_size;

  bool             _available_for_allocation; // Default is true

  MemoryManager*   _managers[max_num_managers];

  int              _num_managers;

  MemoryUsage      _peak_usage;               // Peak memory usage

  MemoryUsage      _after_gc_usage;           // After GC memory usage

  ThresholdSupport* _usage_threshold;

  ThresholdSupport* _gc_usage_threshold;

  SensorInfo*      _usage_sensor;

  SensorInfo*      _gc_usage_sensor;

  volatile instanceOop _memory_pool_obj;

  void add_manager(MemoryManager* mgr);

 public:

  MemoryPool(const char* name,

             PoolType type,

             size_t init_size,

             size_t max_size,

             bool support_usage_threshold,

             bool support_gc_threshold);

  virtual ~MemoryPool() { }

  const char* name()                       { return _name; }

  bool        is_heap()                    { return _type == Heap; }

  bool        is_non_heap()                { return _type == NonHeap; }

  size_t      initial_size()   const       { return _initial_size; }

  int         num_memory_managers() const  { return _num_managers; }

  // max size could be changed

  virtual size_t max_size()    const       { return _max_size; }

  bool is_pool(instanceHandle pool) { return oopDesc::equals(pool(), _memory_pool_obj); }

  bool available_for_allocation()   { return _available_for_allocation; }

  bool set_available_for_allocation(bool value) {

    bool prev = _available_for_allocation;

    _available_for_allocation = value;

    return prev;

  }

  MemoryManager* get_memory_manager(int index) {

    assert(index >= 0 && index < _num_managers, "Invalid index");

    return _managers[index];

  }

  // Records current memory usage if it's a peak usage

  void record_peak_memory_usage();

  MemoryUsage get_peak_memory_usage() {

    // check current memory usage first and then return peak usage

    record_peak_memory_usage();

    return _peak_usage;

  }

  void        reset_peak_memory_usage() {

    _peak_usage = get_memory_usage();

  }

  ThresholdSupport* usage_threshold()      { return _usage_threshold; }

  ThresholdSupport* gc_usage_threshold()   { return _gc_usage_threshold; }

  SensorInfo*       usage_sensor()         {  return _usage_sensor; }

  SensorInfo*       gc_usage_sensor()      { return _gc_usage_sensor; }

  void        set_usage_sensor_obj(instanceHandle s);

  void        set_gc_usage_sensor_obj(instanceHandle s);

  void        set_last_collection_usage(MemoryUsage u)  { _after_gc_usage = u; }

  virtual instanceOop get_memory_pool_instance(TRAPS);

  virtual MemoryUsage get_memory_usage() = 0;

  virtual size_t      used_in_bytes() = 0;

  virtual bool        is_collected_pool()         { return false; }

  virtual MemoryUsage get_last_collection_usage() { return _after_gc_usage; }

  // GC support

  void oops_do(OopClosure* f);

};

class CollectedMemoryPool : public MemoryPool {

public:

  CollectedMemoryPool(const char* name, size_t init_size, size_t max_size, bool support_usage_threshold) :

    MemoryPool(name, MemoryPool::Heap, init_size, max_size, support_usage_threshold, true) {};

  bool is_collected_pool()            { return true; }

};

class CodeHeapPool: public MemoryPool {

private:

  CodeHeap* _codeHeap;

public:

  CodeHeapPool(CodeHeap* codeHeap, const char* name, bool support_usage_threshold);

  MemoryUsage get_memory_usage();

  size_t used_in_bytes()            { return _codeHeap->allocated_capacity(); }

};

class MetaspacePool : public MemoryPool {

  size_t calculate_max_size() const;

 public:

  MetaspacePool();

  MemoryUsage get_memory_usage();

  size_t used_in_bytes();

};

class CompressedKlassSpacePool : public MemoryPool {

 public:

  CompressedKlassSpacePool();

  MemoryUsage get_memory_usage();

  size_t used_in_bytes();

};