Calls to DirectInput EnumDevices sometimes very slow! #1

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1. MrTimcakes

   added

   bugSomething isn't workingSomething isn't working

   on Aug 26, 2021
2. MrTimcakes commented on Aug 26, 2021

   

   MrTimcakes

   on Aug 26, 2021

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   Perhaps the DLL should start a watchdog and timeout the EnumerateDevices function if it takes more than ~300ms?
   Hopefully, as each enumerated device adds to _DeviceInstances in its own callback instance, if we cancel EnumDevices early _DeviceInstances will still be populated with the correct information. 🤞 other devices are processed before we hang. Otherwise, the timeout will need to be in the callback, which will be more difficult to implement.

   This is a very difficult issue to debug as it only happens occasionally.
   Luckily, when it does happen and EnumerateDevices hangs, I can slide the Hz slider on my K70 and EnumerateDevices immediately returns.
3. MrTimcakes commented on Aug 26, 2021

   

   MrTimcakes

   on Aug 26, 2021

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   _EnumDevicesCallback Statistics from 54 samples:

   min = 4900ns
   max = 417400ns
   Range R = 412500ns
   Count n = 54
   sum = 2455500ns
   Mean x̄ = 45472.222ns
   Median x˜ = 44050ns
   mode = 5300, 45200
   Standard Deviation = 75339.76ns
   Variance s2 = 5676079400
4. MrTimcakes commented on Aug 26, 2021

   

   MrTimcakes

   on Aug 26, 2021

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   Upon further inspection, the delay doesn't occur within _EnumDevicesCallback
   Tested when issue is occurring

   _EnumDevicesCallback MrT USB Handbreak: 16000ns
   _EnumDevicesCallback FANATEC CSL Elite Wheel Base PlayStation: 45300ns
   _EnumDevicesCallback FANATEC CSL Elite Wheel Base PlayStation: 43400ns

   EnumDevices: 40192473100ns
5. MrTimcakes commented on Aug 26, 2021

   

   MrTimcakes

   on Aug 26, 2021

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   Made an attempt to exit EnumDevices early but _DeviceInstances isn't populated 😭

   #include <chrono>
   #include <type_traits>
   #include <future>
   #include <thread>
   #include <condition_variable>
   

   DeviceInfo* EnumerateDevices(int& deviceCount) {
     DEBUGDATA.push_back(L"Started Spoofer");
     try {
       std::mutex m;
       std::condition_variable cv;
       DeviceInfo* retValue;
   
       std::thread t([&cv, &retValue, &deviceCount]()
       {
         retValue = EnumerateDevicesReal(deviceCount);
         cv.notify_one();
       });
   
       t.detach();
   
       {
         std::unique_lock<std::mutex> l(m);
         if (cv.wait_for(l, std::chrono::milliseconds(500)) == std::cv_status::timeout)
           throw std::runtime_error("Timeout");
       }
   
       return retValue;
     } catch (std::runtime_error& e) {
       DEBUGDATA.push_back(L"EA! " + _DeviceInstances.size());
       DEBUGDATA.push_back(std::to_wstring(_DeviceInstances.size()));
       return &_DeviceInstances[0];
     }
   }
   
   // Return a vector of all attached devices
   //DeviceInfo* EnumerateDevices(/*[out]*/ int& deviceCount) {
   //  return run_with_timeout(EnumerateDevicesReal, std::chrono::milliseconds(500), deviceCount);
   //}
   
   DeviceInfo* EnumerateDevicesReal(/*[out]*/ int& deviceCount) {
     TimeVar t1 = timeNow();
     HRESULT hr = E_FAIL;
     if (_DirectInput == NULL) { return NULL; } // If DI not ready, return nothing
     _DeviceInstances.clear();                  // Clear devices
   
     // First fetch all devices
     hr = _DirectInput->EnumDevices(    // Invoke device enumeration to the _EnumDevicesCallback callback
       DI8DEVCLASS_GAMECTRL,                    // List devices of type GameController
       _EnumDevicesCallback,                    // Callback executed for each device found
       NULL,                                    // Passed to callback as optional arg
       DIEDFL_ATTACHEDONLY //| DIEDFL_FORCEFEEDBACK
     );
   
     // Next update FFB devices (Important this happens after as it modifies existing entries)
     hr = _DirectInput->EnumDevices(    // Invoke device enumeration to the _EnumDevicesCallback callback
       DI8DEVCLASS_GAMECTRL,                    // List devices of type GameController
       _EnumDevicesCallbackFFB,                 // Callback executed for each device found
       NULL,                                    // Passed to callback as optional arg
       DIEDFL_ATTACHEDONLY | DIEDFL_FORCEFEEDBACK
     );
   
     DEBUGDATA.push_back(L"EnumDevices:" + std::to_wstring(duration(timeNow() - t1)));
   
     if (_DeviceInstances.size() > 0) {
       deviceCount = (int)_DeviceInstances.size();
       return &_DeviceInstances[0]; // Return 1st element, structure size & deviceCount are used to find next elements
     } else {
       deviceCount = 0;
     }
     return NULL;
   }
   
6. MrTimcakes

   added

   DirectInput Bug

   on Dec 20, 2022
7. MrTimcakes

   closed this as completedon Dec 20, 2022
8. MrTimcakes

   closed this as not plannedon Dec 20, 2022