New submission from Terry M. Topka <to...@ge.com>: Attempting to read a fixed amount of data when the serial port is configured for non-blocking reads (i.e. self.timeout == 0) will occasionally throw an invalid memory access exception, due to an error in the following code:
### pyserial-2.5-rc2 serialWin32.py Line 219 if self.timeout == 0: n = min(comstat.cbInQue, size) if n > 0: buf = ctypes.create_string_buffer(n) rc = win32.DWORD() err = win32.ReadFile(self.hComPort, buf, size, ctypes.byref(rc), ctypes.byref(self._overlappedRead)) The buffer length passed to win32.ReadFile should be 'n', not 'size'. This may not have been noticed since it is timing dependent: only if additional input is enqueued inbetween accessing the input queue length and the ReadFile call will the inappropriate invalid memory access exception be raised when 'size' is greater than 'n'. ---------- components: Extension Modules, Windows files: serialwin32.py messages: 127619 nosy: tmtopka priority: normal severity: normal status: open title: Win32Serial.read coding error for non-blocking read type: crash versions: 3rd party, Python 2.6 Added file: http://bugs.python.org/file20628/serialwin32.py _______________________________________ Python tracker <rep...@bugs.python.org> <http://bugs.python.org/issue11080> _______________________________________ _______________________________________________ Python-bugs-list mailing list Unsubscribe: http://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com