自学教程：C++ EnsureInit函数代码示例

 bool OBStereoFacade::HasTetrahedralStereo(unsigned long atomId) {   EnsureInit();   if (m_tetrahedralMap.find(atomId) != m_tetrahedralMap.end())     return true;   return false; }

void KeyFlush(){	if (EnsureInit ())	{		ULONG cElements = INFINITE;		ULONG kcKey;//                HRESULT hr =                               IDirectInputDevice_GetDeviceData (                        g_lpdidKeybd,			sizeof (DIDEVICEOBJECTDATA),			NULL,                        (int *) &cElements,			0);		for (kcKey = 0; kcKey < 256; kcKey ++)		{			g_rgtimeElapsed [kcKey] = 0;			g_rgcDowns [kcKey] = 0;			g_rgcUps [kcKey] = 0;			keyd_pressed [kcKey] = 0;		}		FlushQueue ();	}}

NS_IMETHODIMPnsScreenManagerGtk :: ScreenForNativeWidget (void *aWidget, nsIScreen **outScreen){  nsresult rv;  rv = EnsureInit();  if (NS_FAILED(rv)) {    NS_ERROR("nsScreenManagerGtk::EnsureInit() failed from ScreenForNativeWidget");    return rv;  }  if (mCachedScreenArray.Count() > 1) {    // I don't know how to go from GtkWindow to nsIScreen, especially    // given xinerama and stuff, so let's just do this    gint x, y, width, height, depth;    x = y = width = height = 0;    gdk_window_get_geometry(GDK_WINDOW(aWidget), &x, &y, &width, &height,                            &depth);    gdk_window_get_origin(GDK_WINDOW(aWidget), &x, &y);    rv = ScreenForRect(x, y, width, height, outScreen);  } else {    rv = GetPrimaryScreen(outScreen);  }  return rv;}

const TStrV& TTmInfo::GetDayOfWeekNmV(const TLoc& Loc) {  EnsureInit();  switch (Loc){    case lUs: return UsDayOfWeekNmV;    case lSi: return SiDayOfWeekNmV;    default: Fail; return UsDayOfWeekNmV;  }   }

NS_IMETHODIMP nsCacheEntryDescriptor::nsOutputStreamWrapper::Flush(){    nsresult rv = EnsureInit();    if (NS_FAILED(rv)) return rv;    return mOutput->Flush();}

TStr TTmInfo::GetMonthNm(const int& MonthN, const TLoc& Loc){  EnsureInit();  IAssert((1<=MonthN)&&(MonthN<=12));  switch (Loc){    case lUs: return UsMonthNmV[MonthN-1];    case lSi: return SiMonthNmV[MonthN-1];    default: Fail; return TStr();  }}

nsresult nsCacheEntryDescriptor::nsInputStreamWrapper::Available(uint64_t *avail){    mozilla::MutexAutoLock lock(mLock);    nsresult rv = EnsureInit();    if (NS_FAILED(rv)) return rv;    return mInput->Available(avail);}

//// GetNumberOfScreens//// Returns how many physical screens are available.//NS_IMETHODIMPnsScreenManagerGtk :: GetNumberOfScreens(PRUint32 *aNumberOfScreens){  nsresult rv;  rv = EnsureInit();  if (NS_FAILED(rv)) {    NS_ERROR("nsScreenManagerGtk::EnsureInit() failed from GetNumberOfScreens");    return rv;  }  *aNumberOfScreens = mCachedScreenArray.Count();  return NS_OK;  } // GetNumberOfScreens

nsresult nsCacheEntryDescriptor::nsInputStreamWrapper::Read_Locked(char *buf, uint32_t count, uint32_t *countRead){    nsresult rv = EnsureInit();    if (NS_SUCCEEDED(rv))        rv = mInput->Read(buf, count, countRead);    CACHE_LOG_DEBUG(("nsInputStreamWrapper::Read "                      "[entry=%p, wrapper=%p, mInput=%p, rv=%d]",                      mDescriptor, this, mInput.get(), rv));    return rv;}

//// GetPrimaryScreen//// The screen with the menubar/taskbar. This shouldn't be needed very// often.//NS_IMETHODIMP nsScreenManagerGtk :: GetPrimaryScreen(nsIScreen * *aPrimaryScreen) {  nsresult rv;  rv =  EnsureInit();  if (NS_FAILED(rv)) {    NS_ERROR("nsScreenManagerGtk::EnsureInit() failed from GetPrimaryScreen");    return rv;  }  *aPrimaryScreen = mCachedScreenArray.SafeObjectAt(0);  NS_IF_ADDREF(*aPrimaryScreen);  return NS_OK;  } // GetPrimaryScreen

/// <summary>/// Create new process and attach to it/// </summary>/// <param name="path">Executable path</param>/// <param name="suspended">Leave process in suspended state. To resume process one should resume its main thread</param>/// <param name="forceInit">If 'suspended' is true, this flag will enforce process initialization via second thread</param>/// <param name="cmdLine">Process command line</param>/// <param name="currentDir">Startup directory</param>/// <param name="pStartup">Additional startup params</param>/// <returns>Status code</returns>NTSTATUS Process::CreateAndAttach(     const std::wstring& path,     bool suspended /*= false*/,    bool forceInit /*= true*/,    const std::wstring& cmdLine /*= L""*/,    const wchar_t* currentDir /*= nullptr*/,    STARTUPINFOW* pStartup /*= nullptr*/    ){    Detach();    STARTUPINFOW si = { 0 };    PROCESS_INFORMATION pi = { 0 };    if (!pStartup)        pStartup = &si;    if (!CreateProcessW(        path.c_str(), const_cast<LPWSTR>(cmdLine.c_str()),         NULL, NULL, FALSE, CREATE_SUSPENDED, NULL,         currentDir, pStartup, &pi        ))    {        return LastNtStatus();    }     // Get handle ownership    auto status = _core.Open( pi.hProcess );    if (NT_SUCCESS( status ))    {        _nativeLdr.Init();        // Check if process must be left in suspended mode        if (suspended)        {            // Create new thread to make sure LdrInitializeProcess gets called            if (forceInit)                EnsureInit();        }        else            ResumeThread( pi.hThread );    }    // Close unneeded handles    CloseHandle( pi.hThread );    return status;}

//// ScreenForRect//// Returns the screen that contains the rectangle. If the rect overlaps// multiple screens, it picks the screen with the greatest area of intersection.//// The coordinates are in desktop pixels.//NS_IMETHODIMPnsScreenManagerGtk::ScreenForRect(int32_t aX, int32_t aY,                                  int32_t aWidth, int32_t aHeight,                                  nsIScreen **aOutScreen){  nsresult rv;  rv = EnsureInit();  if (NS_FAILED(rv)) {    NS_ERROR("nsScreenManagerGtk::EnsureInit() failed from ScreenForRect");    return rv;  }  // which screen ( index from zero ) should we return?  uint32_t which = 0;  // Optimize for the common case.  If the number of screens is only  // one then this will fall through with which == 0 and will get the  // primary screen.  if (mCachedScreenArray.Count() > 1) {    // walk the list of screens and find the one that has the most    // surface area.    uint32_t area = 0;    nsIntRect windowRect(aX, aY, aWidth, aHeight);    for (int32_t i = 0, i_end = mCachedScreenArray.Count(); i < i_end; ++i) {      int32_t  x, y, width, height;      x = y = width = height = 0;      mCachedScreenArray[i]->GetRect(&x, &y, &width, &height);      // calculate the surface area      nsIntRect screenRect(x, y, width, height);      screenRect.IntersectRect(screenRect, windowRect);      uint32_t tempArea = screenRect.width * screenRect.height;      if (tempArea >= area) {        which = i;        area = tempArea;      }    }  }  *aOutScreen = mCachedScreenArray.SafeObjectAt(which);  NS_IF_ADDREF(*aOutScreen);  return NS_OK;} // ScreenForRect

IOEventRef IOEventLoop::AddEvent(int fd_or_sig, int16_t events, timeval* timeout,                                 const std::function<bool()>& callback) {  if (!EnsureInit()) {    return nullptr;  }  std::unique_ptr<IOEvent> e(new IOEvent(this, callback));  e->e = event_new(ebase_, fd_or_sig, events, EventCallbackFn, e.get());  if (e->e == nullptr) {    LOG(ERROR) << "event_new() failed";    return nullptr;  }  if (event_add(e->e, timeout) != 0) {    LOG(ERROR) << "event_add() failed";    return nullptr;  }  if (timeout != nullptr) {    e->timeout = *timeout;  }  e->enabled = true;  events_.push_back(std::move(e));  return events_.back().get();}

NS_IMETHODIMPnsScreenManagerGtk :: ScreenForId ( uint32_t aId, nsIScreen **outScreen ){  *outScreen = nullptr;  nsresult rv;  rv = EnsureInit();  if (NS_FAILED(rv)) {    NS_ERROR("nsScreenManagerGtk::EnsureInit() failed from ScreenForId");    return rv;  }  for (int32_t i = 0, i_end = mCachedScreenArray.Count(); i < i_end; ++i) {    uint32_t id;    rv = mCachedScreenArray[i]->GetId(&id);    if (NS_SUCCEEDED(rv) && id == aId) {      NS_IF_ADDREF(*outScreen = mCachedScreenArray[i]);      return NS_OK;    }  }  return NS_ERROR_FAILURE;}

PDMFactory::PDMFactory(){  EnsureInit();  CreatePDMs();  CreateNullPDM();}

PDMFactory::PDMFactory(){  EnsureInit();  CreatePDMs();  CreateBlankPDM();}