/*

 * 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.

 *

 *

 */

// A memory manager is responsible for managing one or more memory pools.

// The garbage collector is one type of memory managers responsible

// for reclaiming memory occupied by unreachable objects.  A Java virtual

// machine may have one or more memory managers.   It may

// add or remove memory managers during execution.

// A memory pool can be managed by more than one memory managers.

class MemoryPool;

class GCMemoryManager;

class OopClosure;

class MemoryManager : public CHeapObj {

private:

  enum {

    max_num_pools = 10

  };

  MemoryPool* _pools[max_num_pools];

  int         _num_pools;

protected:

  volatile instanceOop _memory_mgr_obj;

public:

  enum Name {

    Abstract,

    CodeCache,

    Copy,

    MarkSweepCompact,

    ParNew,

    ConcurrentMarkSweep,

    PSScavenge,

    PSMarkSweep,

    G1YoungGen,

    G1OldGen

  };

  MemoryManager();

  int num_memory_pools() const           { return _num_pools; }

  MemoryPool* get_memory_pool(int index) {

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

    return _pools[index];

  }

  void add_pool(MemoryPool* pool);

  bool is_manager(instanceHandle mh)     { return mh() == _memory_mgr_obj; }

  virtual instanceOop get_memory_manager_instance(TRAPS);

  virtual MemoryManager::Name kind()     { return MemoryManager::Abstract; }

  virtual bool is_gc_memory_manager()    { return false; }

  virtual const char* name() = 0;

  // GC support

  void oops_do(OopClosure* f);

  // Static factory methods to get a memory manager of a specific type

  static MemoryManager*   get_code_cache_memory_manager();

  static GCMemoryManager* get_copy_memory_manager();

  static GCMemoryManager* get_msc_memory_manager();

  static GCMemoryManager* get_parnew_memory_manager();

  static GCMemoryManager* get_cms_memory_manager();

  static GCMemoryManager* get_psScavenge_memory_manager();

  static GCMemoryManager* get_psMarkSweep_memory_manager();

  static GCMemoryManager* get_g1YoungGen_memory_manager();

  static GCMemoryManager* get_g1OldGen_memory_manager();

};

class CodeCacheMemoryManager : public MemoryManager {

private:

public:

  CodeCacheMemoryManager() : MemoryManager() {}

  MemoryManager::Name kind() { return MemoryManager::CodeCache; }

  const char* name()         { return "CodeCacheManager"; }

};

class GCStatInfo : public CHeapObj {

private:

  size_t _index;

  jlong  _start_time;

  jlong  _end_time;

  // We keep memory usage of all memory pools

  MemoryUsage* _before_gc_usage_array;

  MemoryUsage* _after_gc_usage_array;

  int          _usage_array_size;

  void set_gc_usage(int pool_index, MemoryUsage, bool before_gc);

public:

  GCStatInfo(int num_pools);

  ~GCStatInfo();

  size_t gc_index()               { return _index; }

  jlong  start_time()             { return _start_time; }

  jlong  end_time()               { return _end_time; }

  int    usage_array_size()       { return _usage_array_size; }

  MemoryUsage before_gc_usage_for_pool(int pool_index) {

    assert(pool_index >= 0 && pool_index < _usage_array_size, "Range checking");

    return _before_gc_usage_array[pool_index];

  }

  MemoryUsage after_gc_usage_for_pool(int pool_index) {

    assert(pool_index >= 0 && pool_index < _usage_array_size, "Range checking");

    return _after_gc_usage_array[pool_index];

  }

  void set_index(size_t index)    { _index = index; }

  void set_start_time(jlong time) { _start_time = time; }

  void set_end_time(jlong time)   { _end_time = time; }

  void set_before_gc_usage(int pool_index, MemoryUsage usage) {

    assert(pool_index >= 0 && pool_index < _usage_array_size, "Range checking");

    set_gc_usage(pool_index, usage, true /* before gc */);

  }

  void set_after_gc_usage(int pool_index, MemoryUsage usage) {

    assert(pool_index >= 0 && pool_index < _usage_array_size, "Range checking");

    set_gc_usage(pool_index, usage, false /* after gc */);

  }

  void copy_stat(GCStatInfo* stat);

};

class GCMemoryManager : public MemoryManager {

private:

  // TODO: We should unify the GCCounter and GCMemoryManager statistic

  size_t       _num_collections;

  elapsedTimer _accumulated_timer;

  elapsedTimer _gc_timer;         // for measuring every GC duration

  GCStatInfo*  _last_gc_stat;

  int          _num_gc_threads;

public:

  GCMemoryManager();

  ~GCMemoryManager();

  void   initialize_gc_stat_info();

  bool   is_gc_memory_manager()         { return true; }

  jlong  gc_time_ms()                   { return _accumulated_timer.milliseconds(); }

  size_t gc_count()                     { return _num_collections; }

  int    num_gc_threads()               { return _num_gc_threads; }

  void   set_num_gc_threads(int count)  { _num_gc_threads = count; }

  void   gc_begin();

  void   gc_end();

  void        reset_gc_stat()   { _num_collections = 0; _accumulated_timer.reset(); }

  GCStatInfo* last_gc_stat()    { return _last_gc_stat; }

  virtual MemoryManager::Name kind() = 0;

};

// These subclasses of GCMemoryManager are defined to include

// GC-specific information.

// TODO: Add GC-specific information

class CopyMemoryManager : public GCMemoryManager {

private:

public:

  CopyMemoryManager() : GCMemoryManager() {}

  MemoryManager::Name kind() { return MemoryManager::Copy; }

  const char* name()         { return "Copy"; }

};

class MSCMemoryManager : public GCMemoryManager {

private:

public:

  MSCMemoryManager() : GCMemoryManager() {}

  MemoryManager::Name kind() { return MemoryManager::MarkSweepCompact; }

  const char* name()         { return "MarkSweepCompact"; }

};

class ParNewMemoryManager : public GCMemoryManager {

private:

public:

  ParNewMemoryManager() : GCMemoryManager() {}

  MemoryManager::Name kind() { return MemoryManager::ParNew; }

  const char* name()         { return "ParNew"; }

};

class CMSMemoryManager : public GCMemoryManager {

private:

public:

  CMSMemoryManager() : GCMemoryManager() {}

  MemoryManager::Name kind() { return MemoryManager::ConcurrentMarkSweep; }

  const char* name()         { return "ConcurrentMarkSweep";}

};

class PSScavengeMemoryManager : public GCMemoryManager {

private:

public:

  PSScavengeMemoryManager() : GCMemoryManager() {}

  MemoryManager::Name kind() { return MemoryManager::PSScavenge; }

  const char* name()         { return "PS Scavenge"; }

};

class PSMarkSweepMemoryManager : public GCMemoryManager {

private:

public:

  PSMarkSweepMemoryManager() : GCMemoryManager() {}

  MemoryManager::Name kind() { return MemoryManager::PSMarkSweep; }

  const char* name()         { return "PS MarkSweep"; }

};

class G1YoungGenMemoryManager : public GCMemoryManager {

private:

public:

  G1YoungGenMemoryManager() : GCMemoryManager() {}

  MemoryManager::Name kind() { return MemoryManager::G1YoungGen; }

  const char* name()         { return "G1 Young Generation"; }

};

class G1OldGenMemoryManager : public GCMemoryManager {

private:

public:

  G1OldGenMemoryManager() : GCMemoryManager() {}

  MemoryManager::Name kind() { return MemoryManager::G1OldGen; }

  const char* name()         { return "G1 Old Generation"; }

};