/*

 * Copyright (c) 2003, 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

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 */

#ifndef SHARE_SERVICES_MEMORYMANAGER_HPP

#define SHARE_SERVICES_MEMORYMANAGER_HPP

#include "gc/shared/gcCause.hpp"

#include "memory/allocation.hpp"

#include "oops/oop.hpp"

#include "oops/oopsHierarchy.hpp"

#include "runtime/handles.hpp"

#include "runtime/timer.hpp"

#include "services/memoryUsage.hpp"

// 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<mtInternal> {

protected:

  enum {

    max_num_pools = 10

  };

private:

  MemoryPool* _pools[max_num_pools];

  int         _num_pools;

  const char* _name;

protected:

  volatile instanceOop _memory_mgr_obj;

public:

  MemoryManager(const char* name);

  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];

  }

  int add_pool(MemoryPool* pool);

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

  virtual instanceOop get_memory_manager_instance(TRAPS);

  virtual bool is_gc_memory_manager()    { return false; }

  const char* name() const { return _name; }

  // 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 MemoryManager*   get_metaspace_memory_manager();

};

class GCStatInfo : public ResourceObj {

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];

  }

  MemoryUsage* before_gc_usage_array() { return _before_gc_usage_array; }

  MemoryUsage* after_gc_usage_array()  { return _after_gc_usage_array; }

  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 clear();

};

class GCMemoryManager : public MemoryManager {

private:

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

  size_t       _num_collections;

  elapsedTimer _accumulated_timer;

  GCStatInfo*  _last_gc_stat;

  Mutex*       _last_gc_lock;

  GCStatInfo*  _current_gc_stat;

  int          _num_gc_threads;

  volatile bool _notification_enabled;

  const char*  _gc_end_message;

  bool         _pool_always_affected_by_gc[MemoryManager::max_num_pools];

public:

  GCMemoryManager(const char* name, const char* gc_end_message);

  ~GCMemoryManager();

  void add_pool(MemoryPool* pool);

  void add_pool(MemoryPool* pool, bool always_affected_by_gc);

  bool pool_always_affected_by_gc(int index) {

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

    return _pool_always_affected_by_gc[index];

  }

  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(bool recordGCBeginTime, bool recordPreGCUsage,

                  bool recordAccumulatedGCTime);

  void   gc_end(bool recordPostGCUsage, bool recordAccumulatedGCTime,

                bool recordGCEndTime, bool countCollection, GCCause::Cause cause,

                bool allMemoryPoolsAffected);

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

  // Copy out _last_gc_stat to the given destination, returning

  // the collection count. Zero signifies no gc has taken place.

  size_t get_last_gc_stat(GCStatInfo* dest);

  void set_notification_enabled(bool enabled) { _notification_enabled = enabled; }

  bool is_notification_enabled() { return _notification_enabled; }

};

#endif // SHARE_SERVICES_MEMORYMANAGER_HPP