/*
   Copyright (c) 2003, 2015, Oracle and/or its affiliates. All rights reserved.

   This program is free software; you can redistribute it and/or modify
   it under the terms of the GNU General Public License, version 2.0,
   as published by the Free Software Foundation.

   This program is also distributed with certain software (including
   but not limited to OpenSSL) that is licensed under separate terms,
   as designated in a particular file or component or in included license
   documentation.  The authors of MySQL hereby grant you an additional
   permission to link the program and your derivative works with the
   separately licensed software that they have included with MySQL.

   This program 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 2.0, for more details.

   You should have received a copy of the GNU General Public License
   along with this program; if not, write to the Free Software
   Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301  USA
*/

#ifndef LONG_SIGNAL_HPP
#define LONG_SIGNAL_HPP

#include "pc.hpp"
#include <ArrayPool.hpp>
#include "DataBuffer.hpp"

#define JAM_FILE_ID 288

/**
 * NDB_DEBUG_RES_OWNERSHIP
 *
 * Useful for debugging shared resource ownership problems in the lab.
 * Currently implemented for LongSignalMemory.
 * When defined :
 *   - LongSignalMemory segments have an 'owner' tag added to each
 *   - This is maintained mostly by import() and appendToSection()
 *     (Some other segment uses may be uncovered)
 *   - The value is obtained from a thread local value
 *   - The threadlocal is set :
 *      - By the Transporter receiver to 0x1 << 16 | gsn
 *      - By SimulatedBlock::exec to Block << 16 | gsn
 *      - Manually using functions below if desired
 *   - DUMP 2612 can be used to get a breakdown of segments owned
 *     per owner tag
 *   - This can help understand usage, leaks etc...
 *   - The owner tag idea may be useful for other resources in future
 */
//#define NDB_DEBUG_RES_OWNERSHIP

/**
 * Section handling
 */
struct SectionSegment {

  STATIC_CONST( DataLength = NDB_SECTION_SEGMENT_SZ );
  
  union {
    Uint32 m_sz;
    Uint32 chunkSize;
  };
  union {
    Uint32 m_ownerRef;
    Uint32 nextChunk;
  };
  union {
    Uint32 m_lastSegment;
    Uint32 lastChunk;  // 
  };
  union {
    Uint32 m_nextSegment;
    Uint32 nextPool;
  };
  Uint32 theData[DataLength];
};

/**
 * Pool for SectionSegments
 */
class SectionSegmentPool : public ArrayPool<SectionSegment> 
{
private:
  // Print an informative error message.
  static void handleOutOfSegments(ArrayPool<SectionSegment>& pool);
public:
  SectionSegmentPool() : 
    ArrayPool<SectionSegment>(&handleOutOfSegments){}
};

/**
 * And the instance
 */
extern SectionSegmentPool g_sectionSegmentPool;

/**
 * Interface for utils for working with a
 * Section Segment pool - hides details of
 * cache / mt etc.
 */
class SegmentUtils
{
public:
  virtual ~SegmentUtils() {};

  /* 'Provider interface' */
  /* Low level ops needed to build tools */
  virtual SectionSegment* getSegmentPtr(Uint32 iVal) = 0;
  void getSegmentPtr(Ptr<SectionSegment>& ptr, Uint32 iVal);
  virtual bool seizeSegment(Ptr<SectionSegment>& p) = 0;
  virtual void releaseSegment(Uint32 iVal) = 0;

  /* Release a linked list of segments with valid size) */
  virtual void releaseSegmentList(Uint32 iVal) = 0;
};

inline void SegmentUtils::getSegmentPtr(Ptr<SectionSegment>& ptr, Uint32 iVal)
{
  ptr.i = iVal;
  ptr.p = getSegmentPtr(iVal);
}

/* Higher level utils */
/* Currently defined in SegmentList.cpp, should move to somewhere else */
bool sectionAppend(SegmentUtils& su, Uint32& firstSegmentIVal, const Uint32* src, Uint32 len);
bool sectionConsume(SegmentUtils& su, Uint32& firstSegmentIVal, Uint32* dst, Uint32 len);
bool sectionVerify(SegmentUtils& su, Uint32 firstIVal);

/**
 * Function prototypes
 */
void print(SegmentedSectionPtr ptr, FILE* out);
void copy(Uint32 * dst, SegmentedSectionPtr src);
void copy(Uint32 * dst, Uint32 srcFirstIVal);

extern class SectionSegmentPool g_sectionSegmentPool;

/* Defined in SimulatedBlock.cpp */
void getSection(SegmentedSectionPtr & ptr, Uint32 id);
void getSections(Uint32 secCount, SegmentedSectionPtr ptr[3]);
Uint32 getSectionSz(Uint32 id);
Uint32* getLastWordPtr(Uint32 id);

/* Internal verification */
bool verifySection(Uint32 firstIVal, 
                   SectionSegmentPool& thePool= g_sectionSegmentPool);

template<Uint32 sz>
void
append(DataBuffer<sz>& dst, SegmentedSectionPtr ptr, SectionSegmentPool& pool){
  Uint32 len = ptr.sz;
  while(len > SectionSegment::DataLength){
    dst.append(ptr.p->theData, SectionSegment::DataLength);
    ptr.p = pool.getPtr(ptr.p->m_nextSegment);
    len -= SectionSegment::DataLength;
  }
  dst.append(ptr.p->theData, len);
}

#ifdef NDB_DEBUG_RES_OWNERSHIP

void setResOwner(Uint32 id);
Uint32 getResOwner();

/* Util for custom-owner within a scope */
class ResOwnerGuard
{
private:
  Uint32 oldOwner;
public:
  ResOwnerGuard(Uint32 id)
  {
    oldOwner = getResOwner();
    setResOwner(id);
  }
  ~ResOwnerGuard()
  {
    setResOwner(oldOwner);
  }
};

#define DEBUG_RES_OWNER_GUARD(x) ResOwnerGuard _ROG_TMP(x)

#else

#define DEBUG_RES_OWNER_GUARD(x) { }

#endif

#undef JAM_FILE_ID

#endif
