serialwin32.py 文件源码

def write(self, data):
        """Output the given byte string over the serial port."""
        if not self._port_handle:
            raise portNotOpenError
        #~ if not isinstance(data, (bytes, bytearray)):
            #~ raise TypeError('expected %s or bytearray, got %s' % (bytes, type(data)))
        # convert data (needed in case of memoryview instance: Py 3.1 io lib), ctypes doesn't like memoryview
        data = to_bytes(data)
        if data:
            #~ win32event.ResetEvent(self._overlapped_write.hEvent)
            n = win32.DWORD()
            err = win32.WriteFile(self._port_handle, data, len(data), ctypes.byref(n), self._overlapped_write)
            if not err and win32.GetLastError() != win32.ERROR_IO_PENDING:
                raise SerialException("WriteFile failed (%r)" % ctypes.WinError())
            if self._write_timeout != 0:  # if blocking (None) or w/ write timeout (>0)
                # Wait for the write to complete.
                #~ win32.WaitForSingleObject(self._overlapped_write.hEvent, win32.INFINITE)
                err = win32.GetOverlappedResult(self._port_handle, self._overlapped_write, ctypes.byref(n), True)
                if n.value != len(data):
                    raise writeTimeoutError
            return n.value
        else:
            return 0