Issue 119 - Switch to injecting CSS for element hiding

src/plugin/PluginTabBase.cpp

 /*
  * This file is part of Adblock Plus <https://adblockplus.org/>,
- * Copyright (C) 2006-2015 Eyeo GmbH
+ * Copyright (C) 2006-2016 Eyeo GmbH
  *
  * Adblock Plus is free software: you can redistribute it and/or modify
  * it under the terms of the GNU General Public License version 3 as
  * published by the Free Software Foundation.
  *
  * Adblock Plus 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 for more details.
  *
  * You should have received a copy of the GNU General Public License
  * along with Adblock Plus.  If not, see <http://www.gnu.org/licenses/>.
  */
 
 #include "PluginStdAfx.h"
-
-#include "PluginClient.h"
+#include "AdblockPlusClient.h"
+#include "PluginClientBase.h"
 #include "PluginSettings.h"
 #include "AdblockPlusDomTraverser.h"
-#include "PluginClass.h"
 #include "PluginTabBase.h"
-#include "PluginUtil.h"
-#include "../shared/IE_version.h"
-#include <dispex.h>
+#include "IeVersion.h"
+#include "../shared/Utils.h"
+#include "../shared/EventWithSetter.h"
 #include <Mshtmhst.h>
-#include "../shared/Utils.h"
-
-CPluginTabBase::CPluginTabBase(CPluginClass* plugin)
-  : m_plugin(plugin)
-  , m_isActivated(false)
+#include <mutex>
+
+class CPluginTab::AsyncPluginFilter
+{
+public:
+  static std::shared_ptr<AsyncPluginFilter> CreateAsync(const std::wstring& domain)
+  {
+    std::shared_ptr<AsyncPluginFilter> asyncFilter = std::make_shared<AsyncPluginFilter>();
+    std::weak_ptr<AsyncPluginFilter> weakAsyncData = asyncFilter;
+    auto eventSetter = asyncFilter->event.CreateSetter();
+    try
+    {
+      std::thread([domain, weakAsyncData, eventSetter]
+      {
+        try
+        {
+          CreateAsyncImpl(domain, weakAsyncData, eventSetter);
+        }
+        catch (...)
+        {
+          // As a thread-main function, we truncate any C++ exception.
+        }
+      }).detach();
+      // TODO: we should do something with that `detach` above.
+    }
+    catch (const std::system_error& ex)
+    {
+      DEBUG_SYSTEM_EXCEPTION(ex, PLUGIN_ERROR_THREAD, PLUGIN_ERROR_MAIN_THREAD_CREATE_PROCESS,
+        "Class::Thread - Failed to start filter loader thread");
+    }
+    return asyncFilter;
+  }
+  PluginFilterPtr GetFilter()
+  {
+    if (!event.Wait())
+      return PluginFilterPtr();
+    std::lock_guard<std::mutex> lock(mutex);
+    return filter;
+  }
+private:
+  static void CreateAsyncImpl(const std::wstring& domain, std::weak_ptr<AsyncPluginFilter> weakAsyncData, const std::shared_ptr<EventWithSetter::Setter>& setter)
+  {
+    std::unique_ptr<CPluginFilter> pluginFilter(new CPluginFilter(CPluginClient::GetInstance()->GetElementHidingSelectors(domain)));
+    if (auto asyncData = weakAsyncData.lock())
+    {
+      {
+        std::lock_guard<std::mutex> lock(asyncData->mutex);
+        asyncData->filter = move(pluginFilter);
+      }
+      setter->Set();
+    }
+  }
+  EventWithSetter event;
+  std::mutex mutex;
+  PluginFilterPtr filter;
+};
+
+CPluginTab::CPluginTab()
+  : m_isActivated(false)
   , m_continueThreadRunning(true)
 {
-  m_filter = std::auto_ptr<CPluginFilter>(new CPluginFilter());
-  m_filter->hideFiltersLoadedEvent = CreateEvent(NULL, true, false, NULL);
-
   CPluginClient* client = CPluginClient::GetInstance();
   if (AdblockPlus::IE::InstalledMajorVersion() < 10)
   {
     m_isActivated = true;
   }
 
   try
   {
-    m_thread = std::thread(&CPluginTabBase::ThreadProc, this);
+    m_thread = std::thread(&CPluginTab::ThreadProc, this);
   }
   catch (const std::system_error& ex)
   {
     DEBUG_SYSTEM_EXCEPTION(ex, PLUGIN_ERROR_THREAD, PLUGIN_ERROR_TAB_THREAD_CREATE_PROCESS,
       "Tab::Thread - Failed to create tab thread");
   }
-  m_traverser = new CPluginDomTraverser(static_cast<CPluginTab*>(this));
-}
-
-
-CPluginTabBase::~CPluginTabBase()
-{
-  delete m_traverser;
-  m_traverser = NULL;
+}
+
+
+CPluginTab::~CPluginTab()
+{
   m_continueThreadRunning = false;
   if (m_thread.joinable()) {
     m_thread.join();
   }
 }
 
-void CPluginTabBase::OnActivate()
+/**
+ * ABP only intercepts protocols "http:" and "https:".
+ * We can disable any domain used in those protocol with an appropriate whitelist filter.
+ * Thus, the possibility to disable on a particular site depends only on the protocol.
+ */
+bool CPluginTab::IsPossibleToDisableOnSite()
+{
+  auto url = GetDocumentUrl();
+  return BeginsWith(url, L"http:") || BeginsWith(url, L"https:");
+}
+
+void CPluginTab::OnActivate()
 {
   m_isActivated = true;
 }
 
 
-void CPluginTabBase::OnUpdate()
+void CPluginTab::OnUpdate()
 {
   m_isActivated = true;
 }
 
+void CPluginTab::OnNavigate(const std::wstring& url)
+{
+  SetDocumentUrl(url);
+  std::wstring domain = GetDocumentDomain();
+  ClearFrameCache(domain);
+  m_asyncPluginFilter = AsyncPluginFilter::CreateAsync(domain);
+  m_traverser.reset();
+}
+
 namespace
 {
-  // Entry Point
-  void FilterLoader(CPluginTabBase* tabBase)
-  {
-    try
-    {
-      tabBase->m_filter->LoadHideFilters(CPluginClient::GetInstance()->GetElementHidingSelectors(tabBase->GetDocumentDomain()));
-      SetEvent(tabBase->m_filter->hideFiltersLoadedEvent);
-    }
-    catch (...)
-    {
-      // As a thread-main function, we truncate any C++ exception.
-    }
-  }
-}
-
-void CPluginTabBase::OnNavigate(const std::wstring& url)
-{
-  SetDocumentUrl(url);
-  ClearFrameCache(GetDocumentDomain());
-  std::wstring domainString = GetDocumentDomain();
-  ResetEvent(m_filter->hideFiltersLoadedEvent);
-  try
-  {
-    std::thread filterLoaderThread(&FilterLoader, this);
-    filterLoaderThread.detach(); // TODO: but actually we should wait for the thread in the dtr.
-  }
-  catch (const std::system_error& ex)
-  {
-    DEBUG_SYSTEM_EXCEPTION(ex, PLUGIN_ERROR_THREAD, PLUGIN_ERROR_MAIN_THREAD_CREATE_PROCESS,
-      "Class::Thread - Failed to start filter loader thread");
-  }
-  m_traverser->ClearCache();
-}
-
-void CPluginTabBase::InjectABP(IWebBrowser2* browser)
+  /**
+   * Determine if the HTML file is one of ours.
+   * The criterion is that it appear in the "html/templates" folder within our installation.
+   *
+   * Warning: This function may fail if the argument is not a "file://" URL.
+   * This is occasionally the case in circumstances yet to be characterized.
+   */
+  bool IsOurHtmlFile(const std::wstring& url)
+  {
+    // Declared static because the value is derived from an installation directory, which won't change during run-time.
+    static auto dir = FileUrl(HtmlFolderPath());
+
+    DEBUG_GENERAL([&]() -> std::wstring {
+      std::wstring log = L"InjectABP. Current URL: ";
+      log += url;
+      log += L", template directory URL: ";
+      log += dir;
+      return log;
+    }());
+
+    /*
+     * The length check here is defensive, in case the document URL is truncated for some reason.
+     */
+    if (url.length() < 5)
+    {
+      // We can't match ".html" at the end of the URL if it's too short.
+      return false;
+    }
+    auto urlCstr = url.c_str();
+    // Check the prefix to match our directory
+    // Check the suffix to be an HTML file
+    return (_wcsnicmp(urlCstr, dir.c_str(), dir.length()) == 0) &&
+      (_wcsnicmp(urlCstr + url.length() - 5, L".html", 5) == 0);
+  }
+}
+
+void CPluginTab::InjectABP(IWebBrowser2* browser)
 {
   CriticalSection::Lock lock(m_csInject);
   auto url = GetDocumentUrl();
-
-  std::wstring log = L"InjectABP. Current URL: ";
-  log += url;
-  log += L", settings URL: ";
-  log += UserSettingsFileUrl();
-  DEBUG_GENERAL(log);
-
-  CString urlLegacy = ToCString(url);
-  if (!(0 == urlLegacy.CompareNoCase(CString(UserSettingsFileUrl().c_str())) ||
-      0 == urlLegacy.CompareNoCase(CString(FirstRunPageFileUrl().c_str()))))
-  {
-    DEBUG_GENERAL(L"Not injecting");
-    return;
-  }
-  DEBUG_GENERAL(L"Going to inject");
+  if (!IsOurHtmlFile(url))
+  {
+    DEBUG_GENERAL(L"InjectABP. Not injecting");
+    return;
+  }
+  DEBUG_GENERAL(L"InjectABP. Injecting");
   CComPtr<IDispatch> pDocDispatch;
   browser->get_Document(&pDocDispatch);
-  CComQIPtr<IHTMLDocument2> pDoc2 = pDocDispatch;
+  CComQIPtr<IHTMLDocument2> pDoc2(pDocDispatch);
   if (!pDoc2)
   {
-    DEBUG_ERROR_LOG(0, PLUGIN_ERROR_CREATE_SETTINGS_JAVASCRIPT, PLUGIN_ERROR_CREATE_SETTINGS_JAVASCRIPT_INVOKE, "CPluginTabBase::InjectABP - Failed to QI document");
-    return;
-  }
-
+    DEBUG_ERROR_LOG(0, PLUGIN_ERROR_CREATE_SETTINGS_JAVASCRIPT, PLUGIN_ERROR_CREATE_SETTINGS_JAVASCRIPT_INVOKE, "CPluginTab::InjectABP - Failed to QI document");
+    return;
+  }
   CComPtr<IHTMLWindow2> pWnd2;
   pDoc2->get_parentWindow(&pWnd2);
   if (!pWnd2)
   {
-    DEBUG_ERROR_LOG(0, PLUGIN_ERROR_CREATE_SETTINGS_JAVASCRIPT, PLUGIN_ERROR_CREATE_SETTINGS_JAVASCRIPT_INVOKE, "CPluginTabBase::InjectABP - Failed to get parent window");
-    return;
-  }
-  CComQIPtr<IDispatchEx> pWndEx = pWnd2;
+    DEBUG_ERROR_LOG(0, PLUGIN_ERROR_CREATE_SETTINGS_JAVASCRIPT, PLUGIN_ERROR_CREATE_SETTINGS_JAVASCRIPT_INVOKE, "CPluginTab::InjectABP - Failed to get parent window");
+    return;
+  }
+  CComQIPtr<IDispatchEx> pWndEx(pWnd2);
   if (!pWndEx)
   {
-    DEBUG_ERROR_LOG(0, PLUGIN_ERROR_CREATE_SETTINGS_JAVASCRIPT, PLUGIN_ERROR_CREATE_SETTINGS_JAVASCRIPT_INVOKE, "CPluginTabBase::InjectABP - Failed to QI dispatch");
+    DEBUG_ERROR_LOG(0, PLUGIN_ERROR_CREATE_SETTINGS_JAVASCRIPT, PLUGIN_ERROR_CREATE_SETTINGS_JAVASCRIPT_INVOKE, "CPluginTab::InjectABP - Failed to QI dispatch");
     return;
   }
   // Create "Settings" object in JavaScript.
   // A method call of "Settings" in JavaScript, transfered to "Invoke" of m_pluginUserSettings
   DISPID dispid;
   HRESULT hr = pWndEx->GetDispID(L"Settings", fdexNameEnsure, &dispid);
   if (FAILED(hr))
   {
-    DEBUG_ERROR_LOG(hr, PLUGIN_ERROR_CREATE_SETTINGS_JAVASCRIPT, PLUGIN_ERROR_CREATE_SETTINGS_JAVASCRIPT_INVOKE, "CPluginTabBase::InjectABP - Failed to get dispatch");
+    DEBUG_ERROR_LOG(hr, PLUGIN_ERROR_CREATE_SETTINGS_JAVASCRIPT, PLUGIN_ERROR_CREATE_SETTINGS_JAVASCRIPT_INVOKE, "CPluginTab::InjectABP - Failed to get dispatch");
     return;
   }
   CComVariant var((IDispatch*)&m_pluginUserSettings);
 
   DEBUG_GENERAL("Injecting");
 
   DISPPARAMS params;
   params.cArgs = 1;
   params.cNamedArgs = 0;
   params.rgvarg = &var;
   params.rgdispidNamedArgs = 0;
   hr = pWndEx->Invoke(dispid, IID_NULL, LOCALE_USER_DEFAULT, DISPATCH_PROPERTYPUT | DISPATCH_PROPERTYPUTREF, &params, 0, 0, 0);
   DEBUG_GENERAL("Invoke");
   if (FAILED(hr))
   {
-    DEBUG_ERROR_LOG(hr, PLUGIN_ERROR_CREATE_SETTINGS_JAVASCRIPT, PLUGIN_ERROR_CREATE_SETTINGS_JAVASCRIPT_INVOKE, "CPluginTabBase::InjectABP - Failed to create Settings in JavaScript");
-  }
-}
-
-bool CPluginTabBase::IsTraverserEnabled()
+    DEBUG_ERROR_LOG(hr, PLUGIN_ERROR_CREATE_SETTINGS_JAVASCRIPT, PLUGIN_ERROR_CREATE_SETTINGS_JAVASCRIPT_INVOKE, "CPluginTab::InjectABP - Failed to create Settings in JavaScript");
+  }
+}
+
+bool CPluginTab::IsTraverserEnabled()
 {
   return !IsCSSInjectionEnabled();
 }
 
-bool CPluginTabBase::IsCSSInjectionEnabled()
+bool CPluginTab::IsCSSInjectionEnabled()
 {
   return IsWindowsVistaOrLater() && AdblockPlus::IE::InstalledMajorVersion() >= 10;
 }
 
 namespace
 {
   void InjectABPCSS(IHTMLDocument2& htmlDocument2, const std::vector<std::wstring>& hideFilters)
   {
-    // pseudocode: styleHtmlElement = stylePureHtmlElement = htmlDocument2.createElement("style");
-    // pseudocode: stylePureHtmlElement is used later to get styleNode
+    // pseudocode: styleHtmlElement = htmlDocument2.createElement("style");
     ATL::CComQIPtr<IHTMLStyleElement> styleHtmlElement;
     {
       ATL::CComPtr<IHTMLElement> stylePureHtmlElement;
       if (FAILED(htmlDocument2.createElement(ATL::CComBSTR(L"style"), &stylePureHtmlElement)))
       {
         DEBUG_GENERAL(L"Cannot create style element");
         return;
       }
       if (!(styleHtmlElement = stylePureHtmlElement))
       {
@@ skipping 82 matching lines @@
         DEBUG_GENERAL(L"Cannot append blocking style");
       }
     }
   }
 }
 
 namespace
 {
   ATL::CComPtr<IWebBrowser2> GetParent(IWebBrowser2& browser)
   {
-    ATL::CComPtr<IDispatch> browserParentDispatch;
-    if (FAILED(browser.get_Parent(&browserParentDispatch)) || !browserParentDispatch)
+    ATL::CComPtr<IDispatch> parentDispatch;
+    if (FAILED(browser.get_Parent(&parentDispatch)) || !parentDispatch)
     {
       return nullptr;
     }
     // The InternetExplorer application always returns a pointer to itself.
-    if (browserParentDispatch.IsEqualObject(&browser))
+    // https://msdn.microsoft.com/en-us/library/aa752136(v=vs.85).aspx
+    if (parentDispatch.IsEqualObject(&browser))
     {
       return nullptr;
     }
-    ATL::CComQIPtr<IServiceProvider> parentDocumentServiceProvider = browserParentDispatch;
+    ATL::CComQIPtr<IServiceProvider> parentDocumentServiceProvider = parentDispatch;
     if (!parentDocumentServiceProvider)
     {
       return nullptr;
     }
-    ATL::CComPtr<IWebBrowserApp> webBrowserApp;
-    if (FAILED(parentDocumentServiceProvider->QueryService(IID_IWebBrowserApp, &webBrowserApp)) || !webBrowserApp)
+    ATL::CComPtr<IWebBrowser2> parentBrowser;
+    if (FAILED(parentDocumentServiceProvider->QueryService(SID_SWebBrowserApp, &parentBrowser)))
     {
       return nullptr;
     }
-    return ATL::CComQIPtr<IWebBrowser2>(webBrowserApp);
+    return parentBrowser;
   }
 
   bool IsFrameWhiteListed(ATL::CComPtr<IWebBrowser2> frame)
   {
     if (!frame)
     {
       return false;
     }
     auto url = GetLocationUrl(*frame);
     std::vector<std::string> frameHierarchy;
-    for(frame = GetParent(*frame); frame; frame = GetParent(*frame))
+    while(frame = GetParent(*frame))
     {
       frameHierarchy.push_back(ToUtf8String(GetLocationUrl(*frame)));
     }
     CPluginClient* client = CPluginClient::GetInstance();
     return client->IsWhitelistedUrl(url, frameHierarchy)
         || client->IsElemhideWhitelistedOnDomain(url, frameHierarchy);
   }
 }
 
-void CPluginTabBase::OnDownloadComplete(IWebBrowser2* browser)
+void CPluginTab::OnDownloadComplete(IWebBrowser2* browser)
 {
   if (IsTraverserEnabled())
   {
     CPluginClient* client = CPluginClient::GetInstance();
     std::wstring url = GetDocumentUrl();
     if (!client->IsWhitelistedUrl(url) && !client->IsElemhideWhitelistedOnDomain(url))
     {
-      m_traverser->TraverseDocument(browser, GetDocumentDomain(), GetDocumentUrl());
+      if (!m_traverser)
+      {
+        assert(m_asyncPluginFilter && "Filter initialization should be already at least started");
+        if (m_asyncPluginFilter)
+        {
+          auto pluginFilter = m_asyncPluginFilter->GetFilter();
+          assert(pluginFilter && "Plugin filter should be a valid object");
+          if (pluginFilter)
+            m_traverser.reset(new CPluginDomTraverser(pluginFilter));
+        }
+      }
+      assert(m_traverser && "Traverser should be a valid object");
+      if (m_traverser)
+        m_traverser->TraverseDocument(browser, GetDocumentDomain(), GetDocumentUrl());
     }
   }
   InjectABP(browser);
 }
 
-void CPluginTabBase::OnDocumentComplete(IWebBrowser2* browser, const std::wstring& url, bool isDocumentBrowser)
+void CPluginTab::OnDocumentComplete(IWebBrowser2* browser, const std::wstring& url, bool isDocumentBrowser)
 {
   std::wstring documentUrl = GetDocumentUrl();
 
   if (isDocumentBrowser)
   {
     if (url != documentUrl)
     {
       SetDocumentUrl(url);
     }
     InjectABP(browser);
   }
-  CString urlLegacy = ToCString(url);
-  if (urlLegacy.Left(6) == "res://")
+  if (BeginsWith(url, L"res://"))
   {
     return;
   }
   // Get document
   CComPtr<IDispatch> pDocDispatch;
   HRESULT hr = browser->get_Document(&pDocDispatch);
   if (FAILED(hr) || !pDocDispatch)
   {
     return;
   }
 
-  CComQIPtr<IHTMLDocument2> pDoc = pDocDispatch;
+  CComQIPtr<IHTMLDocument2> pDoc(pDocDispatch);
   if (!pDoc)
   {
     return;
   }
 
-  if (IsCSSInjectionEnabled())
+  if (IsCSSInjectionEnabled() && CPluginSettings::GetInstance()->GetPluginEnabled())
   {
     if (!IsFrameWhiteListed(browser))
     {
       DEBUG_GENERAL(L"Inject CSS into " + url);
-      InjectABPCSS(*pDoc, m_filter->GetHideFilters());
+      assert(m_asyncPluginFilter && "Filter initialization should be already at least started");
+      if (m_asyncPluginFilter)
+      {
+        auto pluginFilter = m_asyncPluginFilter->GetFilter();
+        assert(pluginFilter && "Plugin filter should be a valid object");
+        if (pluginFilter)
+        {
+          InjectABPCSS(*pDoc, pluginFilter->GetHideFilters());
+        }
+      }
     }
   }
 
   CComPtr<IOleObject> pOleObj;
-  pDocDispatch->QueryInterface(IID_IOleObject, (void**)&pOleObj);
-
+  pDocDispatch->QueryInterface(&pOleObj);
+  if (!pOleObj)
+  {
+    return;
+  }
   CComPtr<IOleClientSite> pClientSite;
   pOleObj->GetClientSite(&pClientSite);
   if (pClientSite != NULL)
   {
     CComPtr<IDocHostUIHandler> docHostUIHandler;
-    pClientSite->QueryInterface(IID_IDocHostUIHandler, (void**)&docHostUIHandler);
+    pClientSite->QueryInterface(&docHostUIHandler);
     if (docHostUIHandler != NULL)
     {
       docHostUIHandler->UpdateUI();
     }
   }
 }
 
-std::wstring CPluginTabBase::GetDocumentDomain()
+std::wstring CPluginTab::GetDocumentDomain()
 {
   std::wstring domain;
 
   m_criticalSection.Lock();
   {
     domain = m_documentDomain;
   }
   m_criticalSection.Unlock();
 
   return domain;
 }
 
-void CPluginTabBase::SetDocumentUrl(const std::wstring& url)
+void CPluginTab::SetDocumentUrl(const std::wstring& url)
 {
   m_criticalSection.Lock();
   {
     m_documentUrl = url;
     m_documentDomain = CAdblockPlusClient::GetInstance()->GetHostFromUrl(url);
   }
   m_criticalSection.Unlock();
 }
 
-std::wstring CPluginTabBase::GetDocumentUrl()
+std::wstring CPluginTab::GetDocumentUrl()
 {
   std::wstring url;
 
   m_criticalSection.Lock();
   {
     url = m_documentUrl;
   }
   m_criticalSection.Unlock();
 
   return url;
 }
 
 
 // ============================================================================
 // Frame caching
 // ============================================================================
-bool CPluginTabBase::IsFrameCached(const std::wstring& url)
+bool CPluginTab::IsFrameCached(const std::wstring& url)
 {
   bool isFrame;
 
   m_criticalSectionCache.Lock();
   {
     isFrame = m_cacheFrames.find(url) != m_cacheFrames.end();
   }
   m_criticalSectionCache.Unlock();
 
   return isFrame;
 }
 
-void CPluginTabBase::CacheFrame(const std::wstring& url)
+void CPluginTab::CacheFrame(const std::wstring& url)
 {
   m_criticalSectionCache.Lock();
   {
     m_cacheFrames.insert(url);
   }
   m_criticalSectionCache.Unlock();
 }
 
-void CPluginTabBase::ClearFrameCache(const std::wstring& domain)
+void CPluginTab::ClearFrameCache(const std::wstring& domain)
 {
   m_criticalSectionCache.Lock();
   {
     if (domain.empty() || domain != m_cacheDomain)
     {
       m_cacheFrames.clear();
       m_cacheDomain = domain;
     }
   }
   m_criticalSectionCache.Unlock();
 }
 
-void CPluginTabBase::ThreadProc()
+void CPluginTab::ThreadProc()
 {
   // Force loading/creation of settings
-  CPluginSettings::GetInstance()->SetWorkingThreadId();
+  CPluginSettings::GetInstance();
 
   std::string message =
     "================================================================================\n"
     "TAB THREAD process=";
   message += std::to_string(::GetCurrentProcessId());
   message + " thread=";
   message += std::to_string(::GetCurrentThreadId());
   message +=
     "\n"
     "================================================================================";
@@ skipping 32 matching lines @@
           LogQueue::LogPluginError(pluginError.GetErrorCode(), pluginError.GetErrorId(), pluginError.GetErrorSubid(), pluginError.GetErrorDescription(), true, pluginError.GetProcessId(), pluginError.GetThreadId());
         }
 
         // Non-hanging sleep
         Sleep(50);
       }
 
       tabLoopIteration++;
   }
 }