/*

 * Copyright (c) 2013, 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

 * or visit www.oracle.com if you need additional information or have any

 * questions.

 *

 */

#ifndef SHARE_SERVICES_VIRTUALMEMORYTRACKER_HPP

#define SHARE_SERVICES_VIRTUALMEMORYTRACKER_HPP

#if INCLUDE_NMT

#include "memory/allocation.hpp"

#include "services/allocationSite.hpp"

#include "services/nmtCommon.hpp"

#include "utilities/linkedlist.hpp"

#include "utilities/nativeCallStack.hpp"

#include "utilities/ostream.hpp"

/*

 * Virtual memory counter

 */

class VirtualMemory {

 private:

  size_t     _reserved;

  size_t     _committed;

 public:

  VirtualMemory() : _reserved(0), _committed(0) { }

  inline void reserve_memory(size_t sz) { _reserved += sz; }

  inline void commit_memory (size_t sz) {

    _committed += sz;

    assert(_committed <= _reserved, "Sanity check");

  }

  inline void release_memory (size_t sz) {

    assert(_reserved >= sz, "Negative amount");

    _reserved -= sz;

  }

  inline void uncommit_memory(size_t sz) {

    assert(_committed >= sz, "Negative amount");

    _committed -= sz;

  }

  inline size_t reserved()  const { return _reserved;  }

  inline size_t committed() const { return _committed; }

};

// Virtual memory allocation site, keeps track where the virtual memory is reserved.

class VirtualMemoryAllocationSite : public AllocationSite<VirtualMemory> {

 public:

  VirtualMemoryAllocationSite(const NativeCallStack& stack, MEMFLAGS flag) :

    AllocationSite<VirtualMemory>(stack, flag) { }

  inline void reserve_memory(size_t sz)  { data()->reserve_memory(sz);  }

  inline void commit_memory (size_t sz)  { data()->commit_memory(sz);   }

  inline void uncommit_memory(size_t sz) { data()->uncommit_memory(sz); }

  inline void release_memory(size_t sz)  { data()->release_memory(sz);  }

  inline size_t reserved() const  { return peek()->reserved(); }

  inline size_t committed() const { return peek()->committed(); }

};

class VirtualMemorySummary;

// This class represents a snapshot of virtual memory at a given time.

// The latest snapshot is saved in a static area.

class VirtualMemorySnapshot : public ResourceObj {

  friend class VirtualMemorySummary;

 private:

  VirtualMemory  _virtual_memory[mt_number_of_types];

 public:

  inline VirtualMemory* by_type(MEMFLAGS flag) {

    int index = NMTUtil::flag_to_index(flag);

    return &_virtual_memory[index];

  }

  inline VirtualMemory* by_index(int index) {

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

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

    return &_virtual_memory[index];

  }

  inline size_t total_reserved() const {

    size_t amount = 0;

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

      amount += _virtual_memory[index].reserved();

    }

    return amount;

  }

  inline size_t total_committed() const {

    size_t amount = 0;

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

      amount += _virtual_memory[index].committed();

    }

    return amount;

  }

  void copy_to(VirtualMemorySnapshot* s) {

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

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

    }

  }

};

class VirtualMemorySummary : AllStatic {

 public:

  static void initialize();

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

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

  }

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

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

  }

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

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

  }

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

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

  }

  // Move virtual memory from one memory type to another.

  // Virtual memory can be reserved before it is associated with a memory type, and tagged

  // as 'unknown'. Once the memory is tagged, the virtual memory will be moved from 'unknown'

  // type to specified memory type.

  static inline void move_reserved_memory(MEMFLAGS from, MEMFLAGS to, size_t size) {

    as_snapshot()->by_type(from)->release_memory(size);

    as_snapshot()->by_type(to)->reserve_memory(size);

  }

  static inline void move_committed_memory(MEMFLAGS from, MEMFLAGS to, size_t size) {

    as_snapshot()->by_type(from)->uncommit_memory(size);

    as_snapshot()->by_type(to)->commit_memory(size);

  }

  static void snapshot(VirtualMemorySnapshot* s);

  static VirtualMemorySnapshot* as_snapshot() {

    return (VirtualMemorySnapshot*)_snapshot;

  }

 private:

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

};

/*

 * A virtual memory region

 */

class VirtualMemoryRegion {

 private:

  address      _base_address;

  size_t       _size;

 public:

  VirtualMemoryRegion(address addr, size_t size) :

    _base_address(addr), _size(size) {

     assert(addr != NULL, "Invalid address");

     assert(size > 0, "Invalid size");

   }

  inline address base() const { return _base_address;   }

  inline address end()  const { return base() + size(); }

  inline size_t  size() const { return _size;           }

  inline bool is_empty() const { return size() == 0; }

  inline bool contain_address(address addr) const {

    return (addr >= base() && addr < end());

  }

  inline bool contain_region(address addr, size_t size) const {

    return contain_address(addr) && contain_address(addr + size - 1);

  }

  inline bool same_region(address addr, size_t sz) const {

    return (addr == base() && sz == size());

  }

  inline bool overlap_region(address addr, size_t sz) const {

    assert(sz > 0, "Invalid size");

    assert(size() > 0, "Invalid size");

    VirtualMemoryRegion rgn(addr, sz);

    return contain_address(addr) ||

           contain_address(addr + sz - 1) ||

           rgn.contain_address(base()) ||

           rgn.contain_address(end() - 1);

  }

  inline bool adjacent_to(address addr, size_t sz) const {

    return (addr == end() || (addr + sz) == base());

  }

  void exclude_region(address addr, size_t sz) {

    assert(contain_region(addr, sz), "Not containment");

    assert(addr == base() || addr + sz == end(), "Can not exclude from middle");

    size_t new_size = size() - sz;

    if (addr == base()) {

      set_base(addr + sz);

    }

    set_size(new_size);

  }

  void expand_region(address addr, size_t sz) {

    assert(adjacent_to(addr, sz), "Not adjacent regions");

    if (base() == addr + sz) {

      set_base(addr);

    }

    set_size(size() + sz);

  }

 protected:

  void set_base(address base) {

    assert(base != NULL, "Sanity check");

    _base_address = base;

  }

  void set_size(size_t  size) {

    assert(size > 0, "Sanity check");

    _size = size;

  }

};

class CommittedMemoryRegion : public VirtualMemoryRegion {

 private:

  NativeCallStack  _stack;

 public:

  CommittedMemoryRegion(address addr, size_t size, const NativeCallStack& stack) :

    VirtualMemoryRegion(addr, size), _stack(stack) { }

  inline int compare(const CommittedMemoryRegion& rgn) const {

    if (overlap_region(rgn.base(), rgn.size())) {

      return 0;

    } else {

      if (base() == rgn.base()) {

        return 0;

      } else if (base() > rgn.base()) {

        return 1;

      } else {

        return -1;

      }

    }

  }

  inline bool equals(const CommittedMemoryRegion& rgn) const {

    return compare(rgn) == 0;

  }

  inline void set_call_stack(const NativeCallStack& stack) { _stack = stack; }

  inline const NativeCallStack* call_stack() const         { return &_stack; }

};

typedef LinkedListIterator<CommittedMemoryRegion> CommittedRegionIterator;

int compare_committed_region(const CommittedMemoryRegion&, const CommittedMemoryRegion&);

class ReservedMemoryRegion : public VirtualMemoryRegion {

 private:

  SortedLinkedList<CommittedMemoryRegion, compare_committed_region>

    _committed_regions;

  NativeCallStack  _stack;

  MEMFLAGS         _flag;

 public:

  ReservedMemoryRegion(address base, size_t size, const NativeCallStack& stack,

    MEMFLAGS flag = mtNone) :

    VirtualMemoryRegion(base, size), _stack(stack), _flag(flag) { }

  ReservedMemoryRegion(address base, size_t size) :

    VirtualMemoryRegion(base, size), _stack(NativeCallStack::empty_stack()), _flag(mtNone) { }

  // Copy constructor

  ReservedMemoryRegion(const ReservedMemoryRegion& rr) :

    VirtualMemoryRegion(rr.base(), rr.size()) {

    *this = rr;

  }

  inline void  set_call_stack(const NativeCallStack& stack) { _stack = stack; }

  inline const NativeCallStack* call_stack() const          { return &_stack;  }

  void  set_flag(MEMFLAGS flag);

  inline MEMFLAGS flag() const            { return _flag;  }

  inline int compare(const ReservedMemoryRegion& rgn) const {

    if (overlap_region(rgn.base(), rgn.size())) {

      return 0;

    } else {

      if (base() == rgn.base()) {

        return 0;

      } else if (base() > rgn.base()) {

        return 1;

      } else {

        return -1;

      }

    }

  }

  inline bool equals(const ReservedMemoryRegion& rgn) const {

    return compare(rgn) == 0;

  }

  // uncommitted thread stack bottom, above guard pages if there is any.

  address thread_stack_uncommitted_bottom() const;

  bool    add_committed_region(address addr, size_t size, const NativeCallStack& stack);

  bool    remove_uncommitted_region(address addr, size_t size);

  size_t  committed_size() const;

  // move committed regions that higher than specified address to

  // the new region

  void    move_committed_regions(address addr, ReservedMemoryRegion& rgn);

  CommittedRegionIterator iterate_committed_regions() const {

    return CommittedRegionIterator(_committed_regions.head());

  }

  ReservedMemoryRegion& operator= (const ReservedMemoryRegion& other) {

    set_base(other.base());

    set_size(other.size());

    _stack =         *other.call_stack();

    _flag  =         other.flag();

    CommittedRegionIterator itr = other.iterate_committed_regions();

    const CommittedMemoryRegion* rgn = itr.next();

    while (rgn != NULL) {

      _committed_regions.add(*rgn);

      rgn = itr.next();

    }

    return *this;

  }

 private:

  // The committed region contains the uncommitted region, subtract the uncommitted

  // region from this committed region

  bool remove_uncommitted_region(LinkedListNode<CommittedMemoryRegion>* node,

    address addr, size_t sz);

  bool add_committed_region(const CommittedMemoryRegion& rgn) {

    assert(rgn.base() != NULL, "Invalid base address");

    assert(size() > 0, "Invalid size");

    return _committed_regions.add(rgn) != NULL;

  }

};

int compare_reserved_region_base(const ReservedMemoryRegion& r1, const ReservedMemoryRegion& r2);

class VirtualMemoryWalker : public StackObj {

 public:

   virtual bool do_allocation_site(const ReservedMemoryRegion* rgn) { return false; }

};

// Main class called from MemTracker to track virtual memory allocations, commits and releases.

class VirtualMemoryTracker : AllStatic {

  friend class VirtualMemoryTrackerTest;

  friend class CommittedVirtualMemoryTest;

 public:

  static bool initialize(NMT_TrackingLevel level);

  // Late phase initialization

  static bool late_initialize(NMT_TrackingLevel level);

  static bool add_reserved_region (address base_addr, size_t size, const NativeCallStack& stack, MEMFLAGS flag = mtNone);

  static bool add_committed_region      (address base_addr, size_t size, const NativeCallStack& stack);

  static bool remove_uncommitted_region (address base_addr, size_t size);

  static bool remove_released_region    (address base_addr, size_t size);

  static void set_reserved_region_type  (address addr, MEMFLAGS flag);

  // Walk virtual memory data structure for creating baseline, etc.

  static bool walk_virtual_memory(VirtualMemoryWalker* walker);

  static bool transition(NMT_TrackingLevel from, NMT_TrackingLevel to);

  // Snapshot current thread stacks

  static void snapshot_thread_stacks();

 private:

  static SortedLinkedList<ReservedMemoryRegion, compare_reserved_region_base>* _reserved_regions;

};

class MetaspaceSnapshot : public ResourceObj {

private:

public:

  MetaspaceSnapshot();

  static void snapshot(MetaspaceSnapshot& s);

private:

      "Invalid metadata type");

  }

};

#endif // INCLUDE_NMT

#endif // SHARE_SERVICES_VIRTUALMEMORYTRACKER_HPP