{
  HMODULE hModule;
  USERAPIHOOKPROC pfn = NULL, pfn1 = NULL;

  RtlEnterCriticalSection(&gcsUserApiHook);
  hModule = ghmodUserApiHook;
  if ( ghmodUserApiHook == hInstance )
  {
     pfn1 = gpfnInitUserApi;
     if ( --gcLoadUserApiHook == 0 )
     {
        gfUserApiHook = 0;
        ResetUserApiHook(&guah);
        if ( gcCallUserApiHook )
        {
           hInstance = NULL;
           pfn1 = NULL;
           pfn = gpfnInitUserApi;
           gcLoadUserApiHook = 1;
        }
        else
        {
           hInstance = hModule;
           ghmodUserApiHook = NULL;
           gpfnInitUserApi = NULL;
        }
     }
  }
  RtlLeaveCriticalSection(&gcsUserApiHook);

  if ( pfn )
  {
     pfn(uahShutdown, 0); // Shutdown.

     RtlEnterCriticalSection(&gcsUserApiHook);
     pfn1 = gpfnInitUserApi;

     if ( --gcLoadUserApiHook == 0 )
     {
        if ( gcCallUserApiHook )
        {
           hInstance = NULL;
           pfn1 = NULL;
        }
        else
        {
           hInstance = ghmodUserApiHook;
           ghmodUserApiHook = NULL;
           gpfnInitUserApi = NULL;
        }
     }
     RtlLeaveCriticalSection(&gcsUserApiHook);
  }

  if ( pfn1 ) pfn1(uahStop, 0);

  return hInstance != 0;
}

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