/*

 * 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_SNAPSHOT_HPP

#define SHARE_VM_SERVICES_MEM_SNAPSHOT_HPP

#include "memory/allocation.hpp"

#include "runtime/mutex.hpp"

#include "runtime/mutexLocker.hpp"

#include "services/memBaseline.hpp"

#include "services/memPtrArray.hpp"

// Snapshot pointer array iterator

// The pointer array contains malloc-ed pointers

class MemPointerIterator : public MemPointerArrayIteratorImpl {

 public:

  MemPointerIterator(MemPointerArray* arr):

    MemPointerArrayIteratorImpl(arr) {

    assert(arr != NULL, "null array");

  }

#ifdef ASSERT

  virtual bool is_dup_pointer(const MemPointer* ptr1,

    const MemPointer* ptr2) const {

    MemPointerRecord* p1 = (MemPointerRecord*)ptr1;

    MemPointerRecord* p2 = (MemPointerRecord*)ptr2;

    if (p1->addr() != p2->addr()) return false;

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

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

      return false;

    }

    // we do see multiple commit/uncommit on the same memory, it is ok

    return (p1->flags() & MemPointerRecord::tag_masks) == MemPointerRecord::tag_alloc ||

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

  }

  virtual bool insert(MemPointer* ptr) {

    if (_pos > 0) {

      MemPointer* p1 = (MemPointer*)ptr;

      MemPointer* p2 = (MemPointer*)_array->at(_pos - 1);

      assert(!is_dup_pointer(p1, p2),

        err_msg("duplicated pointer, flag = [%x]", (unsigned int)((MemPointerRecord*)p1)->flags()));

    }

     if (_pos < _array->length() -1) {

      MemPointer* p1 = (MemPointer*)ptr;

      MemPointer* p2 = (MemPointer*)_array->at(_pos + 1);

      assert(!is_dup_pointer(p1, p2),

        err_msg("duplicated pointer, flag = [%x]", (unsigned int)((MemPointerRecord*)p1)->flags()));

     }

    return _array->insert_at(ptr, _pos);

  }

  virtual bool insert_after(MemPointer* ptr) {

    if (_pos > 0) {

      MemPointer* p1 = (MemPointer*)ptr;

      MemPointer* p2 = (MemPointer*)_array->at(_pos - 1);

      assert(!is_dup_pointer(p1, p2),

        err_msg("duplicated pointer, flag = [%x]", (unsigned int)((MemPointerRecord*)p1)->flags()));

    }

    if (_pos < _array->length() - 1) {

      MemPointer* p1 = (MemPointer*)ptr;

      MemPointer* p2 = (MemPointer*)_array->at(_pos + 1);

      assert(!is_dup_pointer(p1, p2),

        err_msg("duplicated pointer, flag = [%x]", (unsigned int)((MemPointerRecord*)p1)->flags()));

     }

    if (_array->insert_at(ptr, _pos + 1)) {

      _pos ++;

      return true;

    }

    return false;

  }

#endif

  virtual MemPointer* locate(address addr) {

    MemPointer* cur = current();

    while (cur != NULL && cur->addr() < addr) {

      cur = next();

    }

    return cur;

  }

};

class VMMemPointerIterator : public MemPointerIterator {

 public:

  VMMemPointerIterator(MemPointerArray* arr):

      MemPointerIterator(arr) {

  }

  // locate an existing reserved memory region that contains specified address,

  // or the reserved region just above this address, where the incoming

  // reserved region should be inserted.

  virtual MemPointer* locate(address addr) {

    reset();

    VMMemRegion* reg = (VMMemRegion*)current();

    while (reg != NULL) {

      if (reg->is_reserved_region()) {

        if (reg->contains_address(addr) || addr < reg->base()) {

          return reg;

      }

    }

      reg = (VMMemRegion*)next();

    }

      return NULL;

    }

  // following methods update virtual memory in the context

  // of 'current' position, which is properly positioned by

  // callers via locate method.

  bool add_reserved_region(MemPointerRecord* rec);

  bool add_committed_region(MemPointerRecord* rec);

  bool remove_uncommitted_region(MemPointerRecord* rec);

  bool remove_released_region(MemPointerRecord* rec);

  // split a reserved region to create a new memory region with specified base and size

  bool split_reserved_region(VMMemRegion* rgn, address new_rgn_addr, size_t new_rgn_size);

 private:

  bool insert_record(MemPointerRecord* rec);

  bool insert_record_after(MemPointerRecord* rec);

  bool insert_reserved_region(MemPointerRecord* rec);

  // reset current position

  inline void reset() { _pos = 0; }

#ifdef ASSERT

  virtual bool is_dup_pointer(const MemPointer* ptr1,

    const MemPointer* ptr2) const {

    VMMemRegion* p1 = (VMMemRegion*)ptr1;

    VMMemRegion* p2 = (VMMemRegion*)ptr2;

    if (p1->addr() != p2->addr()) return false;

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

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

      return false;

    }

    // we do see multiple commit/uncommit on the same memory, it is ok

    return (p1->flags() & MemPointerRecord::tag_masks) == MemPointerRecord::tag_alloc ||

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

  }

#endif

};

class MallocRecordIterator : public MemPointerArrayIterator {

 private:

  MemPointerArrayIteratorImpl  _itr;

 public:

  MallocRecordIterator(MemPointerArray* arr) : _itr(arr) {

  }

  virtual MemPointer* current() const {

#ifdef ASSERT

    MemPointer* cur_rec = _itr.current();

    if (cur_rec != NULL) {

      MemPointer* prev_rec = _itr.peek_prev();

      MemPointer* next_rec = _itr.peek_next();

      assert(prev_rec == NULL || prev_rec->addr() < cur_rec->addr(), "Sorting order");

      assert(next_rec == NULL || next_rec->addr() > cur_rec->addr(), "Sorting order");

    }

#endif

    return _itr.current();

  }

  virtual MemPointer* next() {

    MemPointerRecord* next_rec = (MemPointerRecord*)_itr.next();

    // arena memory record is a special case, which we have to compare

    // sequence number against its associated arena record.

    if (next_rec != NULL && next_rec->is_arena_memory_record()) {

      MemPointerRecord* prev_rec = (MemPointerRecord*)_itr.peek_prev();

      // if there is an associated arena record, it has to be previous

      // record because of sorting order (by address) - NMT generates a pseudo address

      // for arena's size record by offsetting arena's address, that guarantees

      // the order of arena record and it's size record.

      if (prev_rec != NULL && prev_rec->is_arena_record() &&

        next_rec->is_memory_record_of_arena(prev_rec)) {

        if (prev_rec->seq() > next_rec->seq()) {

          // Skip this arena memory record

          // Two scenarios:

          //   - if the arena record is an allocation record, this early

          //     size record must be leftover by previous arena,

          //     and the last size record should have size = 0.

          //   - if the arena record is a deallocation record, this

          //     size record should be its cleanup record, which should

          //     also have size = 0. In other world, arena alway reset

          //     its size before gone (see Arena's destructor)

          assert(next_rec->size() == 0, "size not reset");

          return _itr.next();

        } else {

          assert(prev_rec->is_allocation_record(),

            "Arena size record ahead of allocation record");

        }

      }

    }

    return next_rec;

  }

  MemPointer* peek_next() const      { ShouldNotReachHere(); return NULL; }

  MemPointer* peek_prev() const      { ShouldNotReachHere(); return NULL; }

  void remove()                      { ShouldNotReachHere(); }

  bool insert(MemPointer* ptr)       { ShouldNotReachHere(); return false; }

  bool insert_after(MemPointer* ptr) { ShouldNotReachHere(); return false; }

};

// collapse duplicated records. Eliminating duplicated records here, is much

// cheaper than during promotion phase. However, it does have limitation - it

// can only eliminate duplicated records within the generation, there are

// still chances seeing duplicated records during promotion.

// We want to use the record with higher sequence number, because it has

// more accurate callsite pc.

class VMRecordIterator : public MemPointerArrayIterator {

 private:

  MemPointerArrayIteratorImpl  _itr;

 public:

  VMRecordIterator(MemPointerArray* arr) : _itr(arr) {

    MemPointerRecord* cur = (MemPointerRecord*)_itr.current();

    MemPointerRecord* next = (MemPointerRecord*)_itr.peek_next();

    while (next != NULL) {

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

      assert(((SeqMemPointerRecord*)next)->seq() > ((SeqMemPointerRecord*)cur)->seq(),

        "pre-sort order");

      if (is_duplicated_record(cur, next)) {

        _itr.next();

        next = (MemPointerRecord*)_itr.peek_next();

      } else {

        break;

      }

    }

  }

  virtual MemPointer* current() const {

    return _itr.current();

  }

  // get next record, but skip the duplicated records

  virtual MemPointer* next() {

    MemPointerRecord* cur = (MemPointerRecord*)_itr.next();

    MemPointerRecord* next = (MemPointerRecord*)_itr.peek_next();

    while (next != NULL) {

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

      assert(((SeqMemPointerRecord*)next)->seq() > ((SeqMemPointerRecord*)cur)->seq(),

        "pre-sort order");

      if (is_duplicated_record(cur, next)) {

        _itr.next();

        cur = next;

        next = (MemPointerRecord*)_itr.peek_next();

      } else {

        break;

      }

    }

    return cur;

  }

  MemPointer* peek_next() const      { ShouldNotReachHere(); return NULL; }

  MemPointer* peek_prev() const      { ShouldNotReachHere(); return NULL; }

  void remove()                      { ShouldNotReachHere(); }

  bool insert(MemPointer* ptr)       { ShouldNotReachHere(); return false; }

  bool insert_after(MemPointer* ptr) { ShouldNotReachHere(); return false; }

 private:

  bool is_duplicated_record(MemPointerRecord* p1, MemPointerRecord* p2) const {

    bool ret = (p1->addr() == p2->addr() && p1->size() == p2->size() && p1->flags() == p2->flags());

    assert(!(ret && FLAGS_TO_MEMORY_TYPE(p1->flags()) == mtThreadStack), "dup on stack record");

    return ret;

  }

};

class StagingArea : public _ValueObj {

 private:

  MemPointerArray*   _malloc_data;

  MemPointerArray*   _vm_data;

 public:

  StagingArea() : _malloc_data(NULL), _vm_data(NULL) {

    init();

  }

  ~StagingArea() {

    if (_malloc_data != NULL) delete _malloc_data;

    if (_vm_data != NULL) delete _vm_data;

  }

  MallocRecordIterator malloc_record_walker() {

    return MallocRecordIterator(malloc_data());

  }

  VMRecordIterator virtual_memory_record_walker();

  bool init();

  void clear() {

    assert(_malloc_data != NULL && _vm_data != NULL, "Just check");

    _malloc_data->shrink();

    _malloc_data->clear();

    _vm_data->clear();

  }

  inline MemPointerArray* malloc_data() { return _malloc_data; }

  inline MemPointerArray* vm_data()     { return _vm_data; }

};

class MemBaseline;

class MemSnapshot : public CHeapObj<mtNMT> {

 private:

  // the following two arrays contain records of all known lived memory blocks

  // live malloc-ed memory pointers

  MemPointerArray*      _alloc_ptrs;

  // live virtual memory pointers

  MemPointerArray*      _vm_ptrs;

  StagingArea           _staging_area;

  // the lock to protect this snapshot

  Monitor*              _lock;

  NOT_PRODUCT(size_t    _untracked_count;)

  friend class MemBaseline;

 public:

  MemSnapshot();

  virtual ~MemSnapshot();

  // if we are running out of native memory

  bool out_of_memory() {

    return (_alloc_ptrs == NULL ||

      _staging_area.malloc_data() == NULL ||

      _staging_area.vm_data() == NULL ||

      _vm_ptrs == NULL || _lock == NULL ||

      _alloc_ptrs->out_of_memory() ||

      _vm_ptrs->out_of_memory());

  }

  // merge a per-thread memory recorder into staging area

  bool merge(MemRecorder* rec);

  // promote staged data to snapshot

  bool promote();

  void wait(long timeout) {

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

    MonitorLockerEx locker(_lock);

    locker.wait(true, timeout);

  }

  NOT_PRODUCT(void print_snapshot_stats(outputStream* st);)

  NOT_PRODUCT(void check_staging_data();)

  NOT_PRODUCT(void check_malloc_pointers();)

  NOT_PRODUCT(bool has_allocation_record(address addr);)

  // dump all virtual memory pointers in snapshot

  DEBUG_ONLY( void dump_all_vm_pointers();)

 private:

   // copy sequenced pointer from src to dest

   void copy_seq_pointer(MemPointerRecord* dest, const MemPointerRecord* src);

   // assign a sequenced pointer to non-sequenced pointer

   void assign_pointer(MemPointerRecord*dest, const MemPointerRecord* src);

   bool promote_malloc_records(MemPointerArrayIterator* itr);

   bool promote_virtual_memory_records(MemPointerArrayIterator* itr);

};

#endif // SHARE_VM_SERVICES_MEM_SNAPSHOT_HPP