/*

 * 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),

        "dup pointer");

    }

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

      MemPointer* p1 = (MemPointer*)ptr;

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

      assert(!is_dup_pointer(p1, p2),

        "dup pointer");

     }

    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),

        "dup pointer");

    }

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

      MemPointer* p1 = (MemPointer*)ptr;

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

      assert(!is_dup_pointer(p1, p2),

        "dup pointer");

     }

    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 exiting record that contains specified address, or

  // the record, where the record with specified address, should

  // be inserted

  virtual MemPointer* locate(address addr) {

    VMMemRegion* cur = (VMMemRegion*)current();

    VMMemRegion* next_p;

    while (cur != NULL) {

      if (cur->base() > addr) {

        return cur;

      } else {

        // find nearest existing range that has base address <= addr

        next_p = (VMMemRegion*)peek_next();

        if (next_p != NULL && next_p->base() <= addr) {

          cur = (VMMemRegion*)next();

          continue;

        }

      }

      if (cur->is_reserve_record() &&

        cur->base() <= addr &&

        (cur->base() + cur->size() > addr)) {

          return cur;

      } else if (cur->is_commit_record() &&

        cur->base() <= addr &&

        (cur->base() + cur->committed_size() > addr)) {

          return cur;

      }

      cur = (VMMemRegion*)next();

    }

    return NULL;

  }

#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 StagingWalker : public MemPointerArrayIterator {

 private:

  MemPointerArrayIteratorImpl  _itr;

  bool                         _is_vm_record;

  bool                         _end_of_array;

  VMMemRegionEx                _vm_record;

  MemPointerRecordEx           _malloc_record;

 public:

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

    _end_of_array = false;

    next();

  }

  // return the pointer at current position

  MemPointer* current() const {

    if (_end_of_array) {

      return NULL;

    }

    if (is_vm_record()) {

      return (MemPointer*)&_vm_record;

    } else {

      return (MemPointer*)&_malloc_record;

    }

  }

  // return the next pointer and advance current position

  MemPointer* next();

  // type of 'current' record

  bool is_vm_record() const {

    return _is_vm_record;

  }

  // return the next poinger without advancing current position

  MemPointer* peek_next() const {

    assert(false, "not supported");

    return NULL;

  }

  MemPointer* peek_prev() const {

    assert(false, "not supported");

    return NULL;

  }

  // remove the pointer at current position

  void remove() {

    assert(false, "not supported");

  }

  // insert the pointer at current position

  bool insert(MemPointer* ptr) {

    assert(false, "not supported");

    return false;

  }

  bool insert_after(MemPointer* ptr) {

    assert(false, "not supported");

    return false;

  }

 private:

  // consolidate all records referring to this vm region

  bool consolidate_vm_records(VMMemRegionEx* vm_rec);

};

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;

  // stagging a generation's data, before

  // it can be prompted to snapshot

  MemPointerArray*      _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() const {

    return (_alloc_ptrs == NULL || _staging_area == NULL ||

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

      _alloc_ptrs->out_of_memory() ||

      _staging_area->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

  void 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);)

 private:

   // copy pointer data from src to dest

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

};

#endif // SHARE_VM_SERVICES_MEM_SNAPSHOT_HPP