/*

 * Copyright (c) 2012, 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_VM_SERVICES_MEM_RECORDER_HPP

#define SHARE_VM_SERVICES_MEM_RECORDER_HPP

#include "memory/allocation.hpp"

#include "runtime/os.hpp"

#include "services/memPtrArray.hpp"

class MemSnapshot;

class MemTracker;

class MemTrackWorker;

// Fixed size memory pointer array implementation

template <class E, int SIZE> class FixedSizeMemPointerArray :

  public MemPointerArray {

  // This implementation is for memory recorder only

  friend class MemRecorder;

 private:

  E      _data[SIZE];

  int    _size;

 protected:

  FixedSizeMemPointerArray(bool init_elements = false):

   _size(0){

    if (init_elements) {

      for (int index = 0; index < SIZE; index ++) {

        ::new ((void*)&_data[index]) E();

      }

    }

  }

  void* operator new(size_t size, const std::nothrow_t& nothrow_constant) {

    // the instance is part of memRecorder, needs to be tagged with 'otNMTRecorder'

    // to avoid recursion

    return os::malloc(size, (mtNMT | otNMTRecorder));

  }

  void* operator new(size_t size) {

    assert(false, "use nothrow version");

    return NULL;

  }

  void operator delete(void* p) {

    os::free(p, (mtNMT | otNMTRecorder));

  }

  // instance size

  inline size_t instance_size() const {

    return sizeof(FixedSizeMemPointerArray<E, SIZE>);

  }

  debug_only(int capacity() const { return SIZE; })

 public:

  // implementation of public interface

  bool out_of_memory() const { return false; }

  bool is_empty()      const { return _size == 0; }

  bool is_full()             { return length() >= SIZE; }

  int  length()        const { return _size; }

  void clear() {

    _size = 0;

  }

  bool append(MemPointer* ptr) {

    if (is_full()) return false;

    _data[_size ++] = *(E*)ptr;

    return true;

  }

  virtual bool insert_at(MemPointer* p, int pos) {

    assert(false, "append only");

    return false;

  }

  virtual bool remove_at(int pos) {

    assert(false, "not supported");

    return false;

  }

  MemPointer* at(int index) const {

    assert(index >= 0 && index < length(),

      "parameter check");

    return ((E*)&_data[index]);

  }

  void sort(FN_SORT fn) {

    qsort((void*)_data, _size, sizeof(E), fn);

  }

  bool shrink() {

    return false;

  }

};

// This iterator requires pre-sorted MemPointerArray, which is sorted by:

//  1. address

//  2. allocation type

//  3. sequence number

// During the array walking, iterator collapses pointers with the same

// address and allocation type, and only returns the one with highest

// sequence number.

//

// This is read-only iterator, update methods are asserted.

class SequencedRecordIterator : public MemPointerArrayIterator {

 private:

   MemPointerArrayIteratorImpl _itr;

   MemPointer*                 _cur;

 public:

  SequencedRecordIterator(const MemPointerArray* arr):

    _itr(const_cast<MemPointerArray*>(arr)) {

    _cur = next_record();

  }

  SequencedRecordIterator(const SequencedRecordIterator& itr):

    _itr(itr._itr) {

    _cur = next_record();

  }

  // return the pointer at current position

  virtual MemPointer* current() const {

    return _cur;

  };

  // return the next pointer and advance current position

  virtual MemPointer* next() {

    _cur = next_record();

    return _cur;

  }

  // return the next pointer without advancing current position

  virtual MemPointer* peek_next() const {

    assert(false, "not implemented");

    return NULL;

  }

  // return the previous pointer without changing current position

  virtual MemPointer* peek_prev() const {

    assert(false, "not implemented");

    return NULL;

  }

  // remove the pointer at current position

  virtual void remove() {

    assert(false, "read-only iterator");

  };

  // insert the pointer at current position

  virtual bool insert(MemPointer* ptr) {

    assert(false, "read-only iterator");

    return false;

  }

  virtual bool insert_after(MemPointer* ptr) {

    assert(false, "read-only iterator");

    return false;

  }

 private:

  // collapse the 'same kind' of records, and return this 'kind' of

  // record with highest sequence number

  MemPointer* next_record();

  // Test if the two records are the same kind: the same memory block and allocation

  // type.

  inline bool same_kind(const MemPointerRecord* p1, const MemPointerRecord* p2) const {

    return (p1->addr() == p2->addr() &&

      (p1->flags() &MemPointerRecord::tag_masks) ==

      (p2->flags() & MemPointerRecord::tag_masks));

  }

};

#define DEFAULT_RECORDER_PTR_ARRAY_SIZE 512

class MemRecorder : public CHeapObj<mtNMT|otNMTRecorder> {

  friend class MemSnapshot;

  friend class MemTracker;

  friend class MemTrackWorker;

 protected:

  // the array that holds memory records

  MemPointerArray*         _pointer_records;

 private:

  // used for linked list

  MemRecorder*             _next;

  // active recorder can only record a certain generation data

  debug_only(unsigned long _generation;)

 protected:

  _NOINLINE_ MemRecorder();

  ~MemRecorder();

  // record a memory operation

  bool record(address addr, MEMFLAGS flags, size_t size, address caller_pc = 0);

  // linked list support

  inline void set_next(MemRecorder* rec) {

    _next = rec;

  }

  inline MemRecorder* next() const {

    return _next;

  }

  // if the recorder is full

  inline bool is_full() const {

    assert(_pointer_records != NULL, "just check");

    return _pointer_records->is_full();

  }

  // if running out of memory when initializing recorder's internal

  // data

  inline bool out_of_memory() const {

    return (_pointer_records == NULL ||

      _pointer_records->out_of_memory());

  }

  inline void clear() {

    assert(_pointer_records != NULL, "Just check");

    _pointer_records->clear();

  }

  SequencedRecordIterator pointer_itr();

 public:

  // number of MemRecorder instance

  debug_only(static volatile jint _instance_count;)

 private:

  // sorting function, sort records into following order

  // 1. memory address

  // 2. allocation type

  // 3. sequence number

  static int sort_record_fn(const void* e1, const void* e2);

  debug_only(void check_dup_seq(jint seq) const;)

  debug_only(void set_generation();)

};

#endif // SHARE_VM_SERVICES_MEM_RECORDER_HPP