overlapped io, buffers and errors

[Bartman]

I want to improve the reading of HID data.
Currently I have this code

Code: Select all

try:
	win32event.ResetEvent(self._overlappedRead.hEvent)
	rc, buf = win32file.ReadFile(handle, n, self._overlappedRead)
	if rc == 997: #error_io_pending
		#waiting for an event
		win32event.WaitForSingleObject(
			self._overlappedRead.hEvent,
			win32event.INFINITE)
except:
	self.abort = True

The control always flows in the rc == 997 condition. When data arrives, the events gets set and i can process the data in buf. When the device gets disconnected the event also gets set and my data processing algorithms runs on invalid data. I only get the error in the next loop, when I call ReadFile again.