/*

 * Copyright (c) 2014, 2018, 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_MALLOC_TRACKER_HPP

#define SHARE_VM_SERVICES_MALLOC_TRACKER_HPP

#if INCLUDE_NMT

#include "memory/allocation.hpp"

#include "runtime/atomic.hpp"

#include "runtime/threadCritical.hpp"

#include "services/nmtCommon.hpp"

#include "utilities/nativeCallStack.hpp"

/*

 * This counter class counts memory allocation and deallocation,

 * records total memory allocation size and number of allocations.

 * The counters are updated atomically.

 */

class MemoryCounter {

 private:

  volatile size_t   _count;

  volatile size_t   _size;

  DEBUG_ONLY(size_t   _peak_count;)

  DEBUG_ONLY(size_t   _peak_size; )

 public:

  MemoryCounter() : _count(0), _size(0) {

    DEBUG_ONLY(_peak_count = 0;)

    DEBUG_ONLY(_peak_size  = 0;)

  }

  inline void allocate(size_t sz) {

    Atomic::inc(&_count);

    if (sz > 0) {

      Atomic::add(sz, &_size);

      DEBUG_ONLY(_peak_size = MAX2(_peak_size, _size));

    }

    DEBUG_ONLY(_peak_count = MAX2(_peak_count, _count);)

  }

  inline void deallocate(size_t sz) {

    assert(_count > 0, "Nothing allocated yet");

    assert(_size >= sz, "deallocation > allocated");

    Atomic::dec(&_count);

    if (sz > 0) {

      Atomic::sub(sz, &_size);

    }

  }

  inline void resize(long sz) {

    if (sz != 0) {

      Atomic::add(size_t(sz), &_size);

      DEBUG_ONLY(_peak_size = MAX2(_size, _peak_size);)

    }

  }

  inline size_t count() const { return _count; }

  inline size_t size()  const { return _size;  }

  DEBUG_ONLY(inline size_t peak_count() const { return _peak_count; })

  DEBUG_ONLY(inline size_t peak_size()  const { return _peak_size; })

};

/*

 * Malloc memory used by a particular subsystem.

 * It includes the memory acquired through os::malloc()

 * call and arena's backing memory.

 */

class MallocMemory {

 private:

  MemoryCounter _malloc;

  MemoryCounter _arena;

 public:

  MallocMemory() { }

  inline void record_malloc(size_t sz) {

    _malloc.allocate(sz);

  }

  inline void record_free(size_t sz) {

    _malloc.deallocate(sz);

  }

  inline void record_new_arena() {

    _arena.allocate(0);

  }

  inline void record_arena_free() {

    _arena.deallocate(0);

  }

  inline void record_arena_size_change(long sz) {

    _arena.resize(sz);

  }

  inline size_t malloc_size()  const { return _malloc.size(); }

  inline size_t malloc_count() const { return _malloc.count();}

  inline size_t arena_size()   const { return _arena.size();  }

  inline size_t arena_count()  const { return _arena.count(); }

  DEBUG_ONLY(inline const MemoryCounter& malloc_counter() const { return _malloc; })

  DEBUG_ONLY(inline const MemoryCounter& arena_counter()  const { return _arena;  })

};

class MallocMemorySummary;

// A snapshot of malloc'd memory, includes malloc memory

// usage by types and memory used by tracking itself.

class MallocMemorySnapshot : public ResourceObj {

  friend class MallocMemorySummary;

 private:

  MallocMemory      _malloc[mt_number_of_types];

  MemoryCounter     _tracking_header;

 public:

  inline MallocMemory*  by_type(MEMFLAGS flags) {

    int index = NMTUtil::flag_to_index(flags);

    return &_malloc[index];

  }

  inline MallocMemory* by_index(int index) {

    assert(index >= 0, "Index out of bound");

    assert(index < mt_number_of_types, "Index out of bound");

    return &_malloc[index];

  }

  inline MemoryCounter* malloc_overhead() {

    return &_tracking_header;

  }

  // Total malloc'd memory amount

  size_t total() const;

  // Total malloc'd memory used by arenas

  size_t total_arena() const;

  inline size_t thread_count() const {

    MallocMemorySnapshot* s = const_cast<MallocMemorySnapshot*>(this);

    return s->by_type(mtThreadStack)->malloc_count();

  }

  void copy_to(MallocMemorySnapshot* s) {

    // Need to make sure that mtChunks don't get deallocated while the

    // copy is going on, because their size is adjusted using this

    // buffer in make_adjustment().

    ThreadCritical tc;

    s->_tracking_header = _tracking_header;

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

      s->_malloc[index] = _malloc[index];

    }

  }

  // Make adjustment by subtracting chunks used by arenas

  // from total chunks to get total free chunk size

  void make_adjustment();

};

/*

 * This class is for collecting malloc statistics at summary level

 */

class MallocMemorySummary : AllStatic {

 private:

  // Reserve memory for placement of MallocMemorySnapshot object

  static size_t _snapshot[CALC_OBJ_SIZE_IN_TYPE(MallocMemorySnapshot, size_t)];

 public:

   static void initialize();

   static inline void record_malloc(size_t size, MEMFLAGS flag) {

     as_snapshot()->by_type(flag)->record_malloc(size);

   }

   static inline void record_free(size_t size, MEMFLAGS flag) {

     as_snapshot()->by_type(flag)->record_free(size);

   }

   static inline void record_new_arena(MEMFLAGS flag) {

     as_snapshot()->by_type(flag)->record_new_arena();

   }

   static inline void record_arena_free(MEMFLAGS flag) {

     as_snapshot()->by_type(flag)->record_arena_free();

   }

   static inline void record_arena_size_change(long size, MEMFLAGS flag) {

     as_snapshot()->by_type(flag)->record_arena_size_change(size);

   }

   static void snapshot(MallocMemorySnapshot* s) {

     as_snapshot()->copy_to(s);

     s->make_adjustment();

   }

   // Record memory used by malloc tracking header

   static inline void record_new_malloc_header(size_t sz) {

     as_snapshot()->malloc_overhead()->allocate(sz);

   }

   static inline void record_free_malloc_header(size_t sz) {

     as_snapshot()->malloc_overhead()->deallocate(sz);

   }

   // The memory used by malloc tracking headers

   static inline size_t tracking_overhead() {

     return as_snapshot()->malloc_overhead()->size();

   }

  static MallocMemorySnapshot* as_snapshot() {

    return (MallocMemorySnapshot*)_snapshot;

  }

};

/*

 * Malloc tracking header.

 * To satisfy malloc alignment requirement, NMT uses 2 machine words for tracking purpose,

 * which ensures 8-bytes alignment on 32-bit systems and 16-bytes on 64-bit systems (Product build).

 */

class MallocHeader {

#ifdef _LP64

  size_t           _size      : 64;

  size_t           _flags     : 8;

  size_t           _pos_idx   : 16;

  size_t           _bucket_idx: 40;

#define MAX_MALLOCSITE_TABLE_SIZE right_n_bits(40)

#define MAX_BUCKET_LENGTH         right_n_bits(16)

#else

  size_t           _size      : 32;

  size_t           _flags     : 8;

  size_t           _pos_idx   : 8;

  size_t           _bucket_idx: 16;

#define MAX_MALLOCSITE_TABLE_SIZE  right_n_bits(16)

#define MAX_BUCKET_LENGTH          right_n_bits(8)

#endif  // _LP64

 public:

  MallocHeader(size_t size, MEMFLAGS flags, const NativeCallStack& stack, NMT_TrackingLevel level) {

    assert(sizeof(MallocHeader) == sizeof(void*) * 2,

      "Wrong header size");

    if (level == NMT_minimal) {

      return;

    }

    _flags = flags;

    set_size(size);

    if (level == NMT_detail) {

      size_t bucket_idx;

      size_t pos_idx;

      if (record_malloc_site(stack, size, &bucket_idx, &pos_idx, flags)) {

        assert(bucket_idx <= MAX_MALLOCSITE_TABLE_SIZE, "Overflow bucket index");

        assert(pos_idx <= MAX_BUCKET_LENGTH, "Overflow bucket position index");

        _bucket_idx = bucket_idx;

        _pos_idx = pos_idx;

      }

    }

    MallocMemorySummary::record_malloc(size, flags);

    MallocMemorySummary::record_new_malloc_header(sizeof(MallocHeader));

  }

  inline size_t   size()  const { return _size; }

  inline MEMFLAGS flags() const { return (MEMFLAGS)_flags; }

  bool get_stack(NativeCallStack& stack) const;

  // Cleanup tracking information before the memory is released.

  void release() const;

 private:

  inline void set_size(size_t size) {

    _size = size;

  }

  bool record_malloc_site(const NativeCallStack& stack, size_t size,

    size_t* bucket_idx, size_t* pos_idx, MEMFLAGS flags) const;

};

// Main class called from MemTracker to track malloc activities

class MallocTracker : AllStatic {

 public:

  // Initialize malloc tracker for specific tracking level

  static bool initialize(NMT_TrackingLevel level);

  static bool transition(NMT_TrackingLevel from, NMT_TrackingLevel to);

  // malloc tracking header size for specific tracking level

  static inline size_t malloc_header_size(NMT_TrackingLevel level) {

    return (level == NMT_off) ? 0 : sizeof(MallocHeader);

  }

  // Parameter name convention:

  // memblock :   the beginning address for user data

  // malloc_base: the beginning address that includes malloc tracking header

  //

  // The relationship:

  // memblock = (char*)malloc_base + sizeof(nmt header)

  //

  // Record  malloc on specified memory block

  static void* record_malloc(void* malloc_base, size_t size, MEMFLAGS flags,

    const NativeCallStack& stack, NMT_TrackingLevel level);

  // Record free on specified memory block

  static void* record_free(void* memblock);

  // Offset memory address to header address

  static inline void* get_base(void* memblock);

  static inline void* get_base(void* memblock, NMT_TrackingLevel level) {

    if (memblock == NULL || level == NMT_off) return memblock;

    return (char*)memblock - malloc_header_size(level);

  }

  // Get memory size

  static inline size_t get_size(void* memblock) {

    MallocHeader* header = malloc_header(memblock);

    return header->size();

  }

  // Get memory type

  static inline MEMFLAGS get_flags(void* memblock) {

    MallocHeader* header = malloc_header(memblock);

    return header->flags();

  }

  // Get header size

  static inline size_t get_header_size(void* memblock) {

    return (memblock == NULL) ? 0 : sizeof(MallocHeader);

  }

  static inline void record_new_arena(MEMFLAGS flags) {

    MallocMemorySummary::record_new_arena(flags);

  }

  static inline void record_arena_free(MEMFLAGS flags) {

    MallocMemorySummary::record_arena_free(flags);

  }

  static inline void record_arena_size_change(int size, MEMFLAGS flags) {

    MallocMemorySummary::record_arena_size_change(size, flags);

  }

 private:

  static inline MallocHeader* malloc_header(void *memblock) {

    assert(memblock != NULL, "NULL pointer");

    MallocHeader* header = (MallocHeader*)((char*)memblock - sizeof(MallocHeader));

    return header;

  }

};

#endif // INCLUDE_NMT

#endif //SHARE_VM_SERVICES_MALLOC_TRACKER_HPP