text: /////////////////////////////////////////////////////////////////////////////
  // Name:        src/common/memory.cpp
  // Purpose:     Memory checking implementation
  // Author:      Arthur Seaton, Julian Smart
  // Modified by:
  // Created:     04/01/98
  // Copyright:   (c) Julian Smart
  // Licence:     wxWindows licence
  /////////////////////////////////////////////////////////////////////////////
  
  // For compilers that support precompilation, includes "wx.h".
  #include "wx/wxprec.h"
  
  #ifdef __BORLANDC__
      #pragma hdrstop
  #endif
  
  #if wxUSE_MEMORY_TRACING || wxUSE_DEBUG_CONTEXT
  
  #include "wx/memory.h"
  
  #ifndef WX_PRECOMP
      #ifdef __WINDOWS__
          #include "wx/msw/wrapwin.h"
      #endif
      #include "wx/utils.h"
      #include "wx/app.h"
      #include "wx/hash.h"
      #include "wx/log.h"
  #endif
  
  #if wxUSE_THREADS
      #include "wx/thread.h"
  #endif
  
  #include <stdlib.h>
  
  #include "wx/ioswrap.h"
  
  #if !(defined(__VMS__) && ( __VMS_VER < 70000000 ) )
  #include <memory.h>
  #endif
  
  #include <stdarg.h>
  #include <string.h>
  
  #if wxUSE_THREADS
  #define USE_THREADSAFE_MEMORY_ALLOCATION 1
  #else
  #define USE_THREADSAFE_MEMORY_ALLOCATION 0
  #endif
  
  
  #ifdef new
  #undef new
  #endif
  
  // wxDebugContext wxTheDebugContext;
  /*
    Redefine new and delete so that we can pick up situations where:
          - we overwrite or underwrite areas of malloc'd memory.
          - we use uninitialise variables
    Only do this in debug mode.
  
    We change new to get enough memory to allocate a struct, followed
    by the caller's requested memory, followed by a tag. The struct
    is used to create a doubly linked list of these areas and also
    contains another tag. The tags are used to determine when the area
    has been over/under written.
  */
  
  
  /*
    Values which are used to set the markers which will be tested for
    under/over write. There are 3 of these, one in the struct, one
    immediately after the struct but before the caller requested memory and
    one immediately after the requested memory.
  */
  #define MemStartCheck  0x23A8
  #define MemMidCheck  0xA328
  #define MemEndCheck 0x8A32
  #define MemFillChar 0xAF
  #define MemStructId  0x666D
  
  /*
    External interface for the wxMemStruct class. Others are
    defined inline within the class def. Here we only need to be able
    to add and delete nodes from the list and handle errors in some way.
  */
  
  /*
    Used for internal "this shouldn't happen" type of errors.
  */
  void wxMemStruct::ErrorMsg (const char * mesg)
  {
    wxLogMessage(wxT("wxWidgets memory checking error: %s"), mesg);
    PrintNode ();
  }
  
  /*
    Used when we find an overwrite or an underwrite error.
  */
  void wxMemStruct::ErrorMsg ()
  {
    wxLogMessage(wxT("wxWidgets over/underwrite memory error:"));
    PrintNode ();
  }
  
  
  /*
    We want to find out if pointers have been overwritten as soon as is
    possible, so test everything before we dereference it. Of course it's still
    quite possible that, if things have been overwritten, this function will
    fall over, but the only way of dealing with that would cost too much in terms
    of time.
  */
  int wxMemStruct::AssertList ()
  {
      if ((wxDebugContext::GetHead() && !wxDebugContext::GetHead()->AssertIt()) ||
          (wxDebugContext::GetTail() && !wxDebugContext::GetTail()->AssertIt()))
      {
          ErrorMsg ("Head or tail pointers trashed");
          return 0;
      }
      return 1;
  }
  
  
  /*
    Check that the thing we're pointing to has the correct id for a wxMemStruct
    object and also that it's previous and next pointers are pointing at objects
    which have valid ids.
    This is definitely not perfect since we could fall over just trying to access
    any of the slots which we use here, but I think it's about the best that I
    can do without doing something like taking all new wxMemStruct pointers and
    comparing them against all known pointer within the list and then only
    doing this sort of check _after_ you've found the pointer in the list. That
    would be safer, but also much more time consuming.
  */
  int wxMemStruct::AssertIt ()
  {
      return (m_id == MemStructId &&
              (m_prev == 0 || m_prev->m_id == MemStructId) &&
              (m_next == 0 || m_next->m_id == MemStructId));
  }
  
  
  /*
    Additions are always at the tail of the list.
    Returns 0 on error, non-zero on success.
  */
  int wxMemStruct::Append ()
  {
      if (! AssertList ())
          return 0;
  
      if (wxDebugContext::GetHead () == 0) {
          if (wxDebugContext::GetTail () != 0) {
              ErrorMsg ("Null list should have a null tail pointer");
              return 0;
          }
          (void) wxDebugContext::SetHead (this);
          (void) wxDebugContext::SetTail (this);
      } else {
          wxDebugContext::GetTail ()->m_next = this;
          this->m_prev = wxDebugContext::GetTail ();
          (void) wxDebugContext::SetTail (this);
      }
      return 1;
  }
  
  
  /*
    Don't actually free up anything here as the space which is used
    by the node will be free'd up when the whole block is free'd.
    Returns 0 on error, non-zero on success.
  */
  int wxMemStruct::Unlink ()
  {
      if (! AssertList ())
          return 0;
  
      if (wxDebugContext::GetHead () == 0 || wxDebugContext::GetTail () == 0) {
          ErrorMsg ("Trying to remove node from empty list");
          return 0;
      }
  
      // Handle the part of the list before this node.
      if (m_prev == 0) {
          if (this != wxDebugContext::GetHead ()) {
              ErrorMsg ("No previous node for non-head node");
              return 0;
          }
          (void) wxDebugContext::SetHead (m_next);
      } else {
          if (! m_prev->AssertIt ()) {
              ErrorMsg ("Trashed previous pointer");
              return 0;
          }
  
          if (m_prev->m_next != this) {
              ErrorMsg ("List is inconsistent");
              return 0;
          }
          m_prev->m_next = m_next;
      }
  
      // Handle the part of the list after this node.
      if (m_next == 0) {
          if (this != wxDebugContext::GetTail ()) {
              ErrorMsg ("No next node for non-tail node");
              return 0;
          }
          (void) wxDebugContext::SetTail (m_prev);
      } else {
          if (! m_next->AssertIt ()) {
              ErrorMsg ("Trashed next pointer");
              return 0;
          }
  
          if (m_next->m_prev != this) {
              ErrorMsg ("List is inconsistent");
              return 0;
          }
          m_next->m_prev = m_prev;
      }
  
      return 1;
  }
  
  
  
  /*
    Checks a node and block of memory to see that the markers are still
    intact.
  */
  int wxMemStruct::CheckBlock ()
  {
      int nFailures = 0;
  
      if (m_firstMarker != MemStartCheck) {
          nFailures++;
          ErrorMsg ();
      }
  
      char * pointer = wxDebugContext::MidMarkerPos ((char *) this);
      if (* (wxMarkerType *) pointer != MemMidCheck) {
          nFailures++;
          ErrorMsg ();
      }
  
      pointer = wxDebugContext::EndMarkerPos ((char *) this, RequestSize ());
      if (* (wxMarkerType *) pointer != MemEndCheck) {
          nFailures++;
          ErrorMsg ();
      }
  
      return nFailures;
  }
  
  
  /*
    Check the list of nodes to see if they are all ok.
  */
  int wxMemStruct::CheckAllPrevious ()
  {
      int nFailures = 0;
  
      for (wxMemStruct * st = this->m_prev; st != 0; st = st->m_prev) {
          if (st->AssertIt ())
              nFailures += st->CheckBlock ();
          else
              return -1;
      }
  
      return nFailures;
  }
  
  
  /*
    When we delete a node we set the id slot to a specific value and then test
    against this to see if a nodes have been deleted previously. I don't
    just set the entire memory to the fillChar because then I'd be overwriting
    useful stuff like the vtbl which may be needed to output the error message
    including the file name and line numbers. Without this info the whole point
    of this class is lost!
  */
  void wxMemStruct::SetDeleted ()
  {
      m_id = MemFillChar;
  }
  
  int wxMemStruct::IsDeleted ()
  {
      return (m_id == MemFillChar);
  }
  
  
  /*
    Print out a single node. There are many far better ways of doing this
    but this will suffice for now.
  */
  void wxMemStruct::PrintNode ()
  {
    if (m_isObject)
    {
      wxObject *obj = (wxObject *)m_actualData;
      wxClassInfo *info = obj->GetClassInfo();
  
      // Let's put this in standard form so IDEs can load the file at the appropriate
      // line
      wxString msg;
  
      if (m_fileName)
        msg.Printf(wxT("%s(%d): "), m_fileName, (int)m_lineNum);
  
      if (info && info->GetClassName())
        msg += info->GetClassName();
      else
        msg += wxT("object");
  
      wxString msg2;
      msg2.Printf(wxT(" at 0x%lX, size %d"), (long)GetActualData(), (int)RequestSize());
      msg += msg2;
  
      wxLogMessage(msg);
    }
    else
    {
      wxString msg;
  
      if (m_fileName)
        msg.Printf(wxT("%s(%d): "), m_fileName, (int)m_lineNum);
      msg += wxT("non-object data");
      wxString msg2;
      msg2.Printf(wxT(" at 0x%lX, size %d\n"), (long)GetActualData(), (int)RequestSize());
      msg += msg2;
  
      wxLogMessage(msg);
    }
  }
  
  void wxMemStruct::Dump ()
  {
    if (!ValidateNode()) return;
  
    if (m_isObject)
    {
      wxObject *obj = (wxObject *)m_actualData;
  
      wxString msg;
      if (m_fileName)
        msg.Printf(wxT("%s(%d): "), m_fileName, (int)m_lineNum);
  
  
      /* TODO: We no longer have a stream (using wxLogDebug) so we can't dump it.
       * Instead, do what wxObject::Dump does.
       * What should we do long-term, eliminate Dumping? Or specify
       * that MyClass::Dump should use wxLogDebug? Ugh.
      obj->Dump(wxDebugContext::GetStream());
       */
  
      if (obj->GetClassInfo() && obj->GetClassInfo()->GetClassName())
        msg += obj->GetClassInfo()->GetClassName();
      else
        msg += wxT("unknown object class");
  
      wxString msg2;
      msg2.Printf(wxT(" at 0x%lX, size %d"), (long)GetActualData(), (int)RequestSize());
      msg += msg2;
  
      wxDebugContext::OutputDumpLine(msg.c_str());
    }
    else
    {
      wxString msg;
      if (m_fileName)
        msg.Printf(wxT("%s(%d): "), m_fileName, (int)m_lineNum);
  
      wxString msg2;
      msg2.Printf(wxT("non-object data at 0x%lX, size %d"), (long)GetActualData(), (int)RequestSize() );
      msg += msg2;
      wxDebugContext::OutputDumpLine(msg.c_str());
    }
  }
  
  
  /*
    Validate a node. Check to see that the node is "clean" in the sense
    that nothing has over/underwritten it etc.
  */
  int wxMemStruct::ValidateNode ()
  {
      char * startPointer = (char *) this;
      if (!AssertIt ()) {
          if (IsDeleted ())
              ErrorMsg ("Object already deleted");
          else {
              // Can't use the error routines as we have no recognisable object.
  #ifndef __WXGTK__
               wxLogMessage(wxT("Can't verify memory struct - all bets are off!"));
  #endif
          }
          return 0;
      }
  
  /*
      int i;
      for (i = 0; i < wxDebugContext::TotSize (requestSize ()); i++)
        cout << startPointer [i];
      cout << endl;
  */
      if (Marker () != MemStartCheck)
        ErrorMsg ();
      if (* (wxMarkerType *) wxDebugContext::MidMarkerPos (startPointer) != MemMidCheck)
        ErrorMsg ();
      if (* (wxMarkerType *) wxDebugContext::EndMarkerPos (startPointer,
                                                RequestSize ()) !=
          MemEndCheck)
        ErrorMsg ();
  
      // Back to before the extra buffer and check that
      // we can still read what we originally wrote.
      if (Marker () != MemStartCheck ||
          * (wxMarkerType *) wxDebugContext::MidMarkerPos (startPointer)
                           != MemMidCheck ||
          * (wxMarkerType *) wxDebugContext::EndMarkerPos (startPointer,
                                                RequestSize ()) != MemEndCheck)
      {
          ErrorMsg ();
          return 0;
      }
  
      return 1;
  }
  
  /*
    The wxDebugContext class.
  */
  
  wxMemStruct *wxDebugContext::m_head = NULL;
  wxMemStruct *wxDebugContext::m_tail = NULL;
  
  bool wxDebugContext::m_checkPrevious = false;
  int wxDebugContext::debugLevel = 1;
  bool wxDebugContext::debugOn = true;
  wxMemStruct *wxDebugContext::checkPoint = NULL;
  
  // For faster alignment calculation
  static wxMarkerType markerCalc[2];
  int wxDebugContext::m_balign = (int)((char *)&markerCalc[1] - (char*)&markerCalc[0]);
  int wxDebugContext::m_balignmask = (int)((char *)&markerCalc[1] - (char*)&markerCalc[0]) - 1;
  
  // Pointer to global function to call at shutdown
  wxShutdownNotifyFunction wxDebugContext::sm_shutdownFn;
  
  wxDebugContext::wxDebugContext(void)
  {
  }
  
  wxDebugContext::~wxDebugContext(void)
  {
  }
  
  /*
    Work out the positions of the markers by creating an array of 2 markers
    and comparing the addresses of the 2 elements. Use this number as the
    alignment for markers.
  */
  size_t wxDebugContext::CalcAlignment ()
  {
      wxMarkerType ar[2];
      return (char *) &ar[1] - (char *) &ar[0];
  }
  
  
  char * wxDebugContext::StructPos (const char * buf)
  {
      return (char *) buf;
  }
  
  char * wxDebugContext::MidMarkerPos (const char * buf)
  {
      return StructPos (buf) + PaddedSize (sizeof (wxMemStruct));
  }
  
  char * wxDebugContext::CallerMemPos (const char * buf)
  {
      return MidMarkerPos (buf) + PaddedSize (sizeof(wxMarkerType));
  }
  
  
  char * wxDebugContext::EndMarkerPos (const char * buf, size_t size)
  {
      return CallerMemPos (buf) + PaddedSize (size);
  }
  
  
  /*
    Slightly different as this takes a pointer to the start of the caller
    requested region and returns a pointer to the start of the buffer.
    */
  char * wxDebugContext::StartPos (const char * caller)
  {
      return ((char *) (caller - wxDebugContext::PaddedSize (sizeof(wxMarkerType)) -
              wxDebugContext::PaddedSize (sizeof (wxMemStruct))));
  }
  
  /*
    We may need padding between various parts of the allocated memory.
    Given a size of memory, this returns the amount of memory which should
    be allocated in order to allow for alignment of the following object.
  
    I don't know how portable this stuff is, but it seems to work for me at
    the moment. It would be real nice if I knew more about this!
  
    // Note: this function is now obsolete (along with CalcAlignment)
    // because the calculations are done statically, for greater speed.
  */
  size_t wxDebugContext::GetPadding (size_t size)
  {
      size_t pad = size % CalcAlignment ();
      return (pad) ? sizeof(wxMarkerType) - pad : 0;
  }
  
  size_t wxDebugContext::PaddedSize (size_t size)
  {
      // Added by Terry Farnham <TJRT@pacbell.net> to replace
      // slow GetPadding call.
      int padb;
  
      padb = size & m_balignmask;
      if(padb)
          return(size + m_balign - padb);
      else
          return(size);
  }
  
  /*
    Returns the total amount of memory which we need to get from the system
    in order to satisfy a caller request. This includes space for the struct
    plus markers and the caller's memory as well.
  */
  size_t wxDebugContext::TotSize (size_t reqSize)
  {
      return (PaddedSize (sizeof (wxMemStruct)) + PaddedSize (reqSize) +
              2 * sizeof(wxMarkerType));
  }
  
  
  /*
    Traverse the list of nodes executing the given function on each node.
  */
  void wxDebugContext::TraverseList (PmSFV func, wxMemStruct *from)
  {
    if (!from)
      from = wxDebugContext::GetHead ();
  
    wxMemStruct * st = NULL;
    for (st = from; st != 0; st = st->m_next)
    {
        void* data = st->GetActualData();
  //      if ((data != (void*)m_debugStream) && (data != (void*) m_streamBuf))
        if (data != (void*) wxLog::GetActiveTarget())
        {
          (st->*func) ();
        }
    }
  }
  
  
  /*
    Print out the list.
    */
  bool wxDebugContext::PrintList (void)
  {
    TraverseList ((PmSFV)&wxMemStruct::PrintNode, (checkPoint ? checkPoint->m_next : NULL));
  
    return true;
  }
  
  bool wxDebugContext::Dump(void)
  {
    {
      const wxChar* appName = wxT("application");
      wxString appNameStr;
      if (wxTheApp)
      {
          appNameStr = wxTheApp->GetAppName();
          appName = appNameStr.c_str();
          OutputDumpLine(wxT("----- Memory dump of %s at %s -----"), appName, static_cast<const wxChar *>(wxNow().c_str()));
      }
      else
      {
        OutputDumpLine( wxT("----- Memory dump -----") );
      }
    }
  
    TraverseList ((PmSFV)&wxMemStruct::Dump, (checkPoint ? checkPoint->m_next : NULL));
  
    OutputDumpLine(wxEmptyString);
    OutputDumpLine(wxEmptyString);
  
    return true;
  }
  
  struct wxDebugStatsStruct
  {
    long instanceCount;
    long totalSize;
    wxChar *instanceClass;
    wxDebugStatsStruct *next;
  };
  
  static wxDebugStatsStruct *FindStatsStruct(wxDebugStatsStruct *st, wxChar *name)
  {
    while (st)
    {
      if (wxStrcmp(st->instanceClass, name) == 0)
        return st;
      st = st->next;
    }
    return NULL;
  }
  
  static wxDebugStatsStruct *InsertStatsStruct(wxDebugStatsStruct *head, wxDebugStatsStruct *st)
  {
    st->next = head;
    return st;
  }
  
  bool wxDebugContext::PrintStatistics(bool detailed)
  {
    {
      const wxChar* appName = wxT("application");
      wxString appNameStr;
      if (wxTheApp)
      {
          appNameStr = wxTheApp->GetAppName();
          appName = appNameStr.c_str();
          OutputDumpLine(wxT("----- Memory statistics of %s at %s -----"), appName, static_cast<const wxChar *>(wxNow().c_str()));
      }
      else
      {
        OutputDumpLine( wxT("----- Memory statistics -----") );
      }
    }
  
    bool currentMode = GetDebugMode();
    SetDebugMode(false);
  
    long noNonObjectNodes = 0;
    long noObjectNodes = 0;
    long totalSize = 0;
  
    wxDebugStatsStruct *list = NULL;
  
    wxMemStruct *from = (checkPoint ? checkPoint->m_next : NULL );
    if (!from)
      from = wxDebugContext::GetHead ();
  
    wxMemStruct *st;
    for (st = from; st != 0; st = st->m_next)
    {
      void* data = st->GetActualData();
      if (detailed && (data != (void*) wxLog::GetActiveTarget()))
      {
        wxChar *className = (wxChar*) wxT("nonobject");
        if (st->m_isObject && st->GetActualData())
        {
          wxObject *obj = (wxObject *)st->GetActualData();
          if (obj->GetClassInfo()->GetClassName())
            className = (wxChar*)obj->GetClassInfo()->GetClassName();
        }
        wxDebugStatsStruct *stats = FindStatsStruct(list, className);
        if (!stats)
        {
          stats = (wxDebugStatsStruct *)malloc(sizeof(wxDebugStatsStruct));
          stats->instanceClass = className;
          stats->instanceCount = 0;
          stats->totalSize = 0;
          list = InsertStatsStruct(list, stats);
        }
        stats->instanceCount ++;
        stats->totalSize += st->RequestSize();
      }
  
      if (data != (void*) wxLog::GetActiveTarget())
      {
          totalSize += st->RequestSize();
          if (st->m_isObject)
              noObjectNodes ++;
          else
              noNonObjectNodes ++;
      }
    }
  
    if (detailed)
    {
      while (list)
      {
        OutputDumpLine(wxT("%ld objects of class %s, total size %ld"),
            list->instanceCount, list->instanceClass, list->totalSize);
        wxDebugStatsStruct *old = list;
        list = old->next;
        free((char *)old);
      }
      OutputDumpLine(wxEmptyString);
    }
  
    SetDebugMode(currentMode);
  
    OutputDumpLine(wxT("Number of object items: %ld"), noObjectNodes);
    OutputDumpLine(wxT("Number of non-object items: %ld"), noNonObjectNodes);
    OutputDumpLine(wxT("Total allocated size: %ld"), totalSize);
    OutputDumpLine(wxEmptyString);
    OutputDumpLine(wxEmptyString);
  
    return true;
  }
  
  bool wxDebugContext::PrintClasses(void)
  {
    {
      const wxChar* appName = wxT("application");
      wxString appNameStr;
      if (wxTheApp)
      {
          appNameStr = wxTheApp->GetAppName();
          appName = appNameStr.c_str();
          wxLogMessage(wxT("----- Classes in %s -----"), appName);
      }
    }
  
    int n = 0;
    const wxClassInfo *info;
  
    for (wxClassInfo::const_iterator node = wxClassInfo::begin_classinfo(),
                                      end = wxClassInfo::end_classinfo();
         node != end; ++node)
    {
      info = *node;
      if (info->GetClassName())
      {
          wxString msg(info->GetClassName());
          msg += wxT(" ");
  
          if (info->GetBaseClassName1() && !info->GetBaseClassName2())
          {
              msg += wxT("is a ");
              msg += info->GetBaseClassName1();
          }
          else if (info->GetBaseClassName1() && info->GetBaseClassName2())
          {
              msg += wxT("is a ");
              msg += info->GetBaseClassName1() ;
              msg += wxT(", ");
              msg += info->GetBaseClassName2() ;
          }
          if (info->GetConstructor())
              msg += wxT(": dynamic");
  
          wxLogMessage(msg);
      }
      n ++;
    }
    wxLogMessage(wxEmptyString);
    wxLogMessage(wxT("There are %d classes derived from wxObject."), n);
    wxLogMessage(wxEmptyString);
    wxLogMessage(wxEmptyString);
    return true;
  }
  
  void wxDebugContext::SetCheckpoint(bool all)
  {
    if (all)
      checkPoint = NULL;
    else
      checkPoint = m_tail;
  }
  
  // Checks all nodes since checkpoint, or since start.
  int wxDebugContext::Check(bool checkAll)
  {
    int nFailures = 0;
  
    wxMemStruct *from = (checkPoint ? checkPoint->m_next : NULL );
    if (!from || checkAll)
      from = wxDebugContext::GetHead ();
  
    for (wxMemStruct * st = from; st != 0; st = st->m_next)
    {
      if (st->AssertIt ())
        nFailures += st->CheckBlock ();
      else
        return -1;
    }
  
    return nFailures;
  }
  
  // Count the number of non-wxDebugContext-related objects
  // that are outstanding
  int wxDebugContext::CountObjectsLeft(bool sinceCheckpoint)
  {
    int n = 0;
  
    wxMemStruct *from = NULL;
    if (sinceCheckpoint && checkPoint)
      from = checkPoint->m_next;
    else
      from = wxDebugContext::GetHead () ;
  
    for (wxMemStruct * st = from; st != 0; st = st->m_next)
    {
        void* data = st->GetActualData();
        if (data != (void*) wxLog::GetActiveTarget())
            n ++;
    }
  
    return n ;
  }
  
  // This function is used to output the dump
  void wxDebugContext::OutputDumpLine(const wxChar *szFormat, ...)
  {
      // a buffer of 2048 bytes should be long enough for a file name
      // and a class name
      wxChar buf[2048];
      int count;
      va_list argptr;
      va_start(argptr, szFormat);
      buf[WXSIZEOF(buf)-1] = wxT('\0');
  
      // keep 3 bytes for a \r\n\0
      count = wxVsnprintf(buf, WXSIZEOF(buf)-3, szFormat, argptr);
  
      if ( count < 0 )
          count = WXSIZEOF(buf)-3;
      buf[count]=wxT('\r');
      buf[count+1]=wxT('\n');
      buf[count+2]=wxT('\0');
  
      wxMessageOutputDebug dbgout;
      dbgout.Printf(buf);
  }
  
  void wxDebugContext::SetShutdownNotifyFunction(wxShutdownNotifyFunction shutdownFn)
  {
      sm_shutdownFn = shutdownFn;
  }
  
  
  #if USE_THREADSAFE_MEMORY_ALLOCATION
  static bool memSectionOk = false;
  
  class MemoryCriticalSection : public wxCriticalSection
  {
  public:
      MemoryCriticalSection() {
          memSectionOk = true;
      }
      ~MemoryCriticalSection() {
          memSectionOk = false;
      }
  };
  
  class MemoryCriticalSectionLocker
  {
  public:
      inline MemoryCriticalSectionLocker(wxCriticalSection& critsect)
      : m_critsect(critsect), m_locked(memSectionOk) { if(m_locked) m_critsect.Enter(); }
      inline ~MemoryCriticalSectionLocker() { if(m_locked) m_critsect.Leave(); }
  
  private:
      // no assignment operator nor copy ctor
      MemoryCriticalSectionLocker(const MemoryCriticalSectionLocker&);
      MemoryCriticalSectionLocker& operator=(const MemoryCriticalSectionLocker&);
  
      wxCriticalSection& m_critsect;
      bool m_locked;
  };
  
  static MemoryCriticalSection memLocker;
  
  #endif // USE_THREADSAFE_MEMORY_ALLOCATION
  
  
  #if !(defined(__WINDOWS__) && (defined(WXUSINGDLL) || defined(WXMAKINGDLL_BASE)))
  #if wxUSE_GLOBAL_MEMORY_OPERATORS
  void * operator new (size_t size, wxChar * fileName, int lineNum)
  {
      return wxDebugAlloc(size, fileName, lineNum, false, false);
  }
  
  void * operator new (size_t size)
  {
      return wxDebugAlloc(size, NULL, 0, false);
  }
  
  void operator delete (void * buf)
  {
      wxDebugFree(buf, false);
  }
  
  #if wxUSE_ARRAY_MEMORY_OPERATORS
  void * operator new[] (size_t size)
  {
      return wxDebugAlloc(size, NULL, 0, false, true);
  }
  
  void * operator new[] (size_t size, wxChar * fileName, int lineNum)
  {
      return wxDebugAlloc(size, fileName, lineNum, false, true);
  }
  
  void operator delete[] (void * buf)
  {
    wxDebugFree(buf, true);
  }
  #endif // wxUSE_ARRAY_MEMORY_OPERATORS
  #endif // wxUSE_GLOBAL_MEMORY_OPERATORS
  #endif // !(defined(__WINDOWS__) && (defined(WXUSINGDLL) || defined(WXMAKINGDLL_BASE)))
  
  // TODO: store whether this is a vector or not.
  void * wxDebugAlloc(size_t size, wxChar * fileName, int lineNum, bool isObject, bool WXUNUSED(isVect) )
  {
  #if USE_THREADSAFE_MEMORY_ALLOCATION
    MemoryCriticalSectionLocker lock(memLocker);
  #endif
  
    // If not in debugging allocation mode, do the normal thing
    // so we don't leave any trace of ourselves in the node list.
  
    if (!wxDebugContext::GetDebugMode())
    {
      return (void *)malloc(size);
    }
  
      int totSize = wxDebugContext::TotSize (size);
      char * buf = (char *) malloc(totSize);
      if (!buf) {
          wxLogMessage(wxT("Call to malloc (%ld) failed."), (long)size);
          return 0;
      }
      wxMemStruct * st = (wxMemStruct *)buf;
      st->m_firstMarker = MemStartCheck;
      st->m_reqSize = size;
      st->m_fileName = fileName;
      st->m_lineNum = lineNum;
      st->m_id = MemStructId;
      st->m_prev = 0;
      st->m_next = 0;
      st->m_isObject = isObject;
  
      // Errors from Append() shouldn't really happen - but just in case!
      if (st->Append () == 0) {
          st->ErrorMsg ("Trying to append new node");
      }
  
      if (wxDebugContext::GetCheckPrevious ()) {
          if (st->CheckAllPrevious () < 0) {
              st->ErrorMsg ("Checking previous nodes");
          }
      }
  
      // Set up the extra markers at the middle and end.
      char * ptr = wxDebugContext::MidMarkerPos (buf);
      * (wxMarkerType *) ptr = MemMidCheck;
      ptr = wxDebugContext::EndMarkerPos (buf, size);
      * (wxMarkerType *) ptr = MemEndCheck;
  
      // pointer returned points to the start of the caller's
      // usable area.
      void *m_actualData = (void *) wxDebugContext::CallerMemPos (buf);
      st->m_actualData = m_actualData;
  
      return m_actualData;
  }
  
  // TODO: check whether was allocated as a vector
  void wxDebugFree(void * buf, bool WXUNUSED(isVect) )
  {
  #if USE_THREADSAFE_MEMORY_ALLOCATION
    MemoryCriticalSectionLocker lock(memLocker);
  #endif
  
    if (!buf)
      return;
  
    // If not in debugging allocation mode, do the normal thing
    // so we don't leave any trace of ourselves in the node list.
    if (!wxDebugContext::GetDebugMode())
    {
      free((char *)buf);
      return;
    }
  
      // Points to the start of the entire allocated area.
      char * startPointer = wxDebugContext::StartPos ((char *) buf);
      // Find the struct and make sure that it's identifiable.
      wxMemStruct * st = (wxMemStruct *) wxDebugContext::StructPos (startPointer);
  
      if (! st->ValidateNode ())
          return;
  
      // If this is the current checkpoint, we need to
      // move the checkpoint back so it points to a valid
      // node.
      if (st == wxDebugContext::checkPoint)
        wxDebugContext::checkPoint = wxDebugContext::checkPoint->m_prev;
  
      if (! st->Unlink ())
      {
        st->ErrorMsg ("Unlinking deleted node");
      }
  
      // Now put in the fill char into the id slot and the caller requested
      // memory locations.
      st->SetDeleted ();
      (void) memset (wxDebugContext::CallerMemPos (startPointer), MemFillChar,
                     st->RequestSize ());
  
      free((char *)st);
  }
  
  // Trace: send output to the current debugging stream
  void wxTrace(const wxChar * ...)
  {
  #if 1
      wxFAIL_MSG(wxT("wxTrace is now obsolete. Please use wxDebugXXX instead."));
  #else
      va_list ap;
    static wxChar buffer[512];
  
    va_start(ap, fmt);
  
  #ifdef __WINDOWS__
    wvsprintf(buffer,fmt,ap) ;
  #else
    vsprintf(buffer,fmt,ap) ;
  #endif
  
    va_end(ap);
  
    if (wxDebugContext::HasStream())
    {
      wxDebugContext::GetStream() << buffer;
      wxDebugContext::GetStream().flush();
    }
    else
  #ifdef __WINDOWS__
  #ifdef __WIN32__
      OutputDebugString((LPCTSTR)buffer) ;
  #else
      OutputDebugString((const char*) buffer) ;
  #endif
  #else
      fprintf(stderr, buffer);
  #endif
  #endif
  }
  
  // Trace with level
  void wxTraceLevel(int, const wxChar * ...)
  {
  #if 1
      wxFAIL_MSG(wxT("wxTrace is now obsolete. Please use wxDebugXXX instead."));
  #else
    if (wxDebugContext::GetLevel() < level)
      return;
  
    va_list ap;
    static wxChar buffer[512];
  
    va_start(ap, fmt);
  
  #ifdef __WINDOWS__
    wxWvsprintf(buffer,fmt,ap) ;
  #else
    vsprintf(buffer,fmt,ap) ;
  #endif
  
    va_end(ap);
  
    if (wxDebugContext::HasStream())
    {
      wxDebugContext::GetStream() << buffer;
      wxDebugContext::GetStream().flush();
    }
    else
  #ifdef __WINDOWS__
  #ifdef __WIN32__
      OutputDebugString((LPCTSTR)buffer) ;
  #else
      OutputDebugString((const char*) buffer) ;
  #endif
  #else
      fprintf(stderr, buffer);
  #endif
  #endif
  }
  
  //----------------------------------------------------------------------------
  // Final cleanup after all global objects in all files have been destroyed
  //----------------------------------------------------------------------------
  
  // Don't set it to 0 by dynamic initialization
  // Some compilers will really do the assignment later
  // All global variables are initialized to 0 at the very beginning, and this is just fine.
  int wxDebugContextDumpDelayCounter::sm_count;
  
  wxDebugContextDumpDelayCounter::wxDebugContextDumpDelayCounter()
  {
      sm_count++;
  }
  
  wxDebugContextDumpDelayCounter::~wxDebugContextDumpDelayCounter()
  {
      if ( !--sm_count )
      {
          // Notify app if we've been asked to do that
          if( wxDebugContext::sm_shutdownFn )
              wxDebugContext::sm_shutdownFn();
          DoDump();
      }
  }
  
  void wxDebugContextDumpDelayCounter::DoDump()
  {
      if (wxDebugContext::CountObjectsLeft(true) > 0)
      {
          wxDebugContext::OutputDumpLine(wxT("There were memory leaks.\n"));
          wxDebugContext::Dump();
          wxDebugContext::PrintStatistics();
      }
  }
  
  // Even if there is nothing else, make sure that there is at
  // least one cleanup counter object
  static wxDebugContextDumpDelayCounter wxDebugContextDumpDelayCounter_One;
  
  #endif // wxUSE_MEMORY_TRACING || wxUSE_DEBUG_CONTEXT
  