def write(self, data): """Output the given byte string over the serial port.""" if not self.is_open: raise portNotOpenError d = to_bytes(data) tx_len = length = len(d) timeout = Timeout(self._write_timeout) while tx_len > 0: try: n = os.write(self.fd, d) if timeout.is_non_blocking: # Zero timeout indicates non-blocking - simply return the # number of bytes of data actually written return n elif not timeout.is_infinite: # when timeout is set, use select to wait for being ready # with the time left as timeout if timeout.expired(): raise writeTimeoutError abort, ready, _ = select.select([self.pipe_abort_write_r], [self.fd], [], timeout.time_left()) if abort: os.read(self.pipe_abort_write_r, 1000) break if not ready: raise writeTimeoutError else: assert timeout.time_left() is None # wait for write operation abort, ready, _ = select.select([self.pipe_abort_write_r], [self.fd], [], None) if abort: os.read(self.pipe_abort_write_r, 1) break if not ready: raise SerialException('write failed (select)') d = d[n:] tx_len -= n except SerialException: raise except OSError as e: # this is for Python 3.x where select.error is a subclass of # OSError ignore BlockingIOErrors and EINTR. other errors are shown # https://www.python.org/dev/peps/pep-0475. if e.errno not in (errno.EAGAIN, errno.EALREADY, errno.EWOULDBLOCK, errno.EINPROGRESS, errno.EINTR): raise SerialException('write failed: {}'.format(e)) except select.error as e: # this is for Python 2.x # ignore BlockingIOErrors and EINTR. all errors are shown # see also http://www.python.org/dev/peps/pep-3151/#select if e[0] not in (errno.EAGAIN, errno.EALREADY, errno.EWOULDBLOCK, errno.EINPROGRESS, errno.EINTR): raise SerialException('write failed: {}'.format(e)) if not timeout.is_non_blocking and timeout.expired(): raise writeTimeoutError return length - len(d)
def write(self, data): """\ Output the given byte string over the serial port. Can block if the connection is blocked. May raise SerialException if the connection is closed. """ if not self.is_open: raise portNotOpenError d = to_bytes(data) tx_len = length = len(d) timeout = Timeout(self._write_timeout) while tx_len > 0: try: n = self._socket.send(d) if timeout.is_non_blocking: # Zero timeout indicates non-blocking - simply return the # number of bytes of data actually written return n elif not timeout.is_infinite: # when timeout is set, use select to wait for being ready # with the time left as timeout if timeout.expired(): raise writeTimeoutError _, ready, _ = select.select([], [self._socket], [], timeout.time_left()) if not ready: raise writeTimeoutError else: assert timeout.time_left() is None # wait for write operation _, ready, _ = select.select([], [self._socket], [], None) if not ready: raise SerialException('write failed (select)') d = d[n:] tx_len -= n except SerialException: raise except OSError as e: # this is for Python 3.x where select.error is a subclass of # OSError ignore BlockingIOErrors and EINTR. other errors are shown # https://www.python.org/dev/peps/pep-0475. if e.errno not in (errno.EAGAIN, errno.EALREADY, errno.EWOULDBLOCK, errno.EINPROGRESS, errno.EINTR): raise SerialException('write failed: {}'.format(e)) except select.error as e: # this is for Python 2.x # ignore BlockingIOErrors and EINTR. all errors are shown # see also http://www.python.org/dev/peps/pep-3151/#select if e[0] not in (errno.EAGAIN, errno.EALREADY, errno.EWOULDBLOCK, errno.EINPROGRESS, errno.EINTR): raise SerialException('write failed: {}'.format(e)) if not timeout.is_non_blocking and timeout.expired(): raise writeTimeoutError return length - len(d)
def write(self, data): """Output the given byte string over the serial port.""" if not self.is_open: raise portNotOpenError d = to_bytes(data) tx_len = length = len(d) timeout = Timeout(self._write_timeout) while tx_len > 0: try: n = os.write(self.fd, d) if timeout.is_non_blocking: # Zero timeout indicates non-blocking - simply return the # number of bytes of data actually written return n elif not timeout.is_infinite: # when timeout is set, use select to wait for being ready # with the time left as timeout if timeout.expired(): raise writeTimeoutError abort, ready, _ = select.select([self.pipe_abort_write_r], [self.fd], [], timeout.time_left()) if abort: os.read(self.pipe_abort_write_r, 1000) break if not ready: raise writeTimeoutError else: assert timeout.time_left() is None # wait for write operation abort, ready, _ = select.select([self.pipe_abort_write_r], [self.fd], [], None) if abort: os.read(self.pipe_abort_write_r, 1) break if not ready: raise SerialException('write failed (select)') d = d[n:] tx_len -= n except SerialException: raise except OSError as v: if v.errno != errno.EAGAIN: raise SerialException('write failed: {}'.format(v)) # still calculate and check timeout if timeout.expired(): raise writeTimeoutError return length - len(d)
def read(self, size=1): """\ Read size bytes from the serial port. If a timeout is set it may return less characters as requested. With no timeout it will block until the requested number of bytes is read. """ if not self.is_open: raise PortNotOpenError() read = bytearray() timeout = Timeout(self._timeout) poll = select.poll() poll.register(self.fd, select.POLLIN | select.POLLERR | select.POLLHUP | select.POLLNVAL) poll.register(self.pipe_abort_read_r, select.POLLIN | select.POLLERR | select.POLLHUP | select.POLLNVAL) if size > 0: while len(read) < size: # print "\tread(): size",size, "have", len(read) #debug # wait until device becomes ready to read (or something fails) for fd, event in poll.poll(None if timeout.is_infinite else (timeout.time_left() * 1000)): if fd == self.pipe_abort_read_r: break if event & (select.POLLERR | select.POLLHUP | select.POLLNVAL): raise SerialException('device reports error (poll)') # we don't care if it is select.POLLIN or timeout, that's # handled below if fd == self.pipe_abort_read_r: os.read(self.pipe_abort_read_r, 1000) break buf = os.read(self.fd, size - len(read)) read.extend(buf) if timeout.expired() \ or (self._inter_byte_timeout is not None and self._inter_byte_timeout > 0) and not buf: break # early abort on timeout return bytes(read)
def read(self, size=1): """\ Read size bytes from the serial port. If a timeout is set it may return less characters as requested. With no timeout it will block until the requested number of bytes is read. """ if not self.is_open: raise PortNotOpenError() read = bytearray() timeout = Timeout(self._timeout) while len(read) < size: try: ready, _, _ = select.select([self.fd, self.pipe_abort_read_r], [], [], timeout.time_left()) if self.pipe_abort_read_r in ready: os.read(self.pipe_abort_read_r, 1000) break # If select was used with a timeout, and the timeout occurs, it # returns with empty lists -> thus abort read operation. # For timeout == 0 (non-blocking operation) also abort when # there is nothing to read. if not ready: break # timeout buf = os.read(self.fd, size - len(read)) except OSError as e: # this is for Python 3.x where select.error is a subclass of # OSError ignore BlockingIOErrors and EINTR. other errors are shown # https://www.python.org/dev/peps/pep-0475. if e.errno not in (errno.EAGAIN, errno.EALREADY, errno.EWOULDBLOCK, errno.EINPROGRESS, errno.EINTR): raise SerialException('read failed: {}'.format(e)) except select.error as e: # this is for Python 2.x # ignore BlockingIOErrors and EINTR. all errors are shown # see also http://www.python.org/dev/peps/pep-3151/#select if e[0] not in (errno.EAGAIN, errno.EALREADY, errno.EWOULDBLOCK, errno.EINPROGRESS, errno.EINTR): raise SerialException('read failed: {}'.format(e)) else: # read should always return some data as select reported it was # ready to read when we get to this point. if not buf: # Disconnected devices, at least on Linux, show the # behavior that they are always ready to read immediately # but reading returns nothing. raise SerialException( 'device reports readiness to read but returned no data ' '(device disconnected or multiple access on port?)') read.extend(buf) if timeout.expired(): break elif self._inter_byte_timeout is not None and self._inter_byte_timeout > 0: #atleast one char received --> overwrite timeout by setting it to inter_byte_timeout timeout = Timeout(self._inter_byte_timeout) return bytes(read)
def read(self, size=1): """\ Read size bytes from the serial port. If a timeout is set it may return less characters as requested. With no timeout it will block until the requested number of bytes is read. """ if not self.is_open: raise PortNotOpenError() read = bytearray() timeout = Timeout(self._timeout) while len(read) < size: try: ready, _, _ = select.select([self._socket], [], [], timeout.time_left()) # If select was used with a timeout, and the timeout occurs, it # returns with empty lists -> thus abort read operation. # For timeout == 0 (non-blocking operation) also abort when # there is nothing to read. if not ready: break # timeout buf = self._socket.recv(size - len(read)) # read should always return some data as select reported it was # ready to read when we get to this point, unless it is EOF if not buf: raise SerialException('socket disconnected') read.extend(buf) except OSError as e: # this is for Python 3.x where select.error is a subclass of # OSError ignore BlockingIOErrors and EINTR. other errors are shown # https://www.python.org/dev/peps/pep-0475. if e.errno not in (errno.EAGAIN, errno.EALREADY, errno.EWOULDBLOCK, errno.EINPROGRESS, errno.EINTR): raise SerialException('read failed: {}'.format(e)) except (select.error, socket.error) as e: # this is for Python 2.x # ignore BlockingIOErrors and EINTR. all errors are shown # see also http://www.python.org/dev/peps/pep-3151/#select if e[0] not in (errno.EAGAIN, errno.EALREADY, errno.EWOULDBLOCK, errno.EINPROGRESS, errno.EINTR): raise SerialException('read failed: {}'.format(e)) if timeout.expired(): break return bytes(read)
def write(self, data): """Output the given byte string over the serial port.""" if not self.is_open: raise portNotOpenError d = to_bytes(data) tx_len = len(d) timeout = Timeout(self._write_timeout) while tx_len > 0: try: n = os.write(self.fd, d) if timeout.is_non_blocking: # Zero timeout indicates non-blocking - simply return the # number of bytes of data actually written return n elif not timeout.is_infinite: # when timeout is set, use select to wait for being ready # with the time left as timeout if timeout.expired(): raise writeTimeoutError abort, ready, _ = select.select([self.pipe_abort_write_r], [self.fd], [], timeout.time_left()) if abort: os.read(self.pipe_abort_write_r, 1000) break if not ready: raise writeTimeoutError else: assert timeout.time_left() is None # wait for write operation abort, ready, _ = select.select([self.pipe_abort_write_r], [self.fd], [], None) if abort: os.read(self.pipe_abort_write_r, 1) break if not ready: raise SerialException('write failed (select)') d = d[n:] tx_len -= n except SerialException: raise except OSError as v: if v.errno != errno.EAGAIN: raise SerialException('write failed: {}'.format(v)) # still calculate and check timeout if timeout.expired(): raise writeTimeoutError return len(data)
def read(self, size=1): if not self.is_open: raise portNotOpenError data = bytearray() try: timeout = Timeout(self._timeout) while len(data) < size: if self._thread is None: raise SerialException( 'connection failed (reader thread died)') buf = self._read_buffer.get(True, timeout.time_left()) if buf is None: return bytes(data) data += buf if timeout.expired(): break except Queue.Empty: # -> timeout pass return bytes(data)
def read(self, size=1): """\ Read size bytes from the serial port. If a timeout is set it may return less characters as requested. With no timeout it will block until the requested number of bytes is read. """ if not self.is_open: raise portNotOpenError read = bytearray() timeout = Timeout(self._timeout) while len(read) < size: try: ready, _, _ = select.select([self._socket], [], [], timeout.time_left()) # If select was used with a timeout, and the timeout occurs, it # returns with empty lists -> thus abort read operation. # For timeout == 0 (non-blocking operation) also abort when # there is nothing to read. if not ready: break # timeout buf = self._socket.recv(size - len(read)) # read should always return some data as select reported it was # ready to read when we get to this point, unless it is EOF if not buf: raise SerialException('socket disconnected') read.extend(buf) except OSError as e: # this is for Python 3.x where select.error is a subclass of # OSError ignore BlockingIOErrors and EINTR. other errors are shown # https://www.python.org/dev/peps/pep-0475. if e.errno not in (errno.EAGAIN, errno.EALREADY, errno.EWOULDBLOCK, errno.EINPROGRESS, errno.EINTR): raise SerialException('read failed: {}'.format(e)) except (select.error, socket.error) as e: # this is for Python 2.x # ignore BlockingIOErrors and EINTR. all errors are shown # see also http://www.python.org/dev/peps/pep-3151/#select if e[0] not in (errno.EAGAIN, errno.EALREADY, errno.EWOULDBLOCK, errno.EINPROGRESS, errno.EINTR): raise SerialException('read failed: {}'.format(e)) if timeout.expired(): break return bytes(read)
def read(self, size=1): """\ Read size bytes from the serial port. If a timeout is set it may return less characters as requested. With no timeout it will block until the requested number of bytes is read. """ if not self.is_open: raise portNotOpenError read = bytearray() timeout = Timeout(self._timeout) while len(read) < size: try: ready, _, _ = select.select([self.fd, self.pipe_abort_read_r], [], [], timeout.time_left()) if self.pipe_abort_read_r in ready: os.read(self.pipe_abort_read_r, 1000) break # If select was used with a timeout, and the timeout occurs, it # returns with empty lists -> thus abort read operation. # For timeout == 0 (non-blocking operation) also abort when # there is nothing to read. if not ready: break # timeout buf = os.read(self.fd, size - len(read)) # read should always return some data as select reported it was # ready to read when we get to this point. if not buf: # Disconnected devices, at least on Linux, show the # behavior that they are always ready to read immediately # but reading returns nothing. raise SerialException( 'device reports readiness to read but returned no data ' '(device disconnected or multiple access on port?)') read.extend(buf) except OSError as e: # this is for Python 3.x where select.error is a subclass of # OSError ignore EAGAIN errors. all other errors are shown if e.errno != errno.EAGAIN and e.errno != errno.EINTR: raise SerialException('read failed: {}'.format(e)) except select.error as e: # this is for Python 2.x # ignore EAGAIN errors. all other errors are shown # see also http://www.python.org/dev/peps/pep-3151/#select if e[0] != errno.EAGAIN: raise SerialException('read failed: {}'.format(e)) if timeout.expired(): break return bytes(read)
def read(self, size=1): """\ Read size bytes from the serial port. If a timeout is set it may return less characters as requested. With no timeout it will block until the requested number of bytes is read. """ if not self.is_open: raise portNotOpenError read = bytearray() timeout = Timeout(self._timeout) while len(read) < size: try: ready, _, _ = select.select([self.fd, self.pipe_abort_read_r], [], [], timeout.time_left()) if self.pipe_abort_read_r in ready: os.read(self.pipe_abort_read_r, 1000) break # If select was used with a timeout, and the timeout occurs, it # returns with empty lists -> thus abort read operation. # For timeout == 0 (non-blocking operation) also abort when # there is nothing to read. if not ready: break # timeout buf = os.read(self.fd, size - len(read)) # read should always return some data as select reported it was # ready to read when we get to this point. if not buf: # Disconnected devices, at least on Linux, show the # behavior that they are always ready to read immediately # but reading returns nothing. raise SerialException( 'device reports readiness to read but returned no data ' '(device disconnected or multiple access on port?)') read.extend(buf) except OSError as e: # Devices connecting through a poor USB/Serial cable or an # underpowered USB hub can spontaneously disconnect from # the OS, and promptly reconnect. If this happens, attempt # to reopen the device and continue the session. if e.errno == errno.ENXIO: retryTimeout = Timeout(2) # Allow for a short grace period sys.stderr.write( 'pySerial WARNING: Serial device disappeared! ' '...Trying to reconnect...\n') sys.stderr.write( 'pySerial WARNING: If this problem is chronic ' 'replace your cable/powered USB HUB.\n') sys.stderr.flush() self.close() while self.fd == None: try: self.open() except OSError as e: if e.errno != errno.ENOENT or retryTimeout.expired( ): raise SerialException( 'Serial device gone: {}'.format(e)) break # this is for Python 3.x where select.error is a subclass of # OSError ignore BlockingIOErrors and EINTR. other errors are shown # https://www.python.org/dev/peps/pep-0475. elif e.errno not in (errno.EAGAIN, errno.EALREADY, errno.EWOULDBLOCK, errno.EINPROGRESS, errno.EINTR): raise SerialException('read failed: {}'.format(e)) except select.error as e: # this is for Python 2.x # ignore BlockingIOErrors and EINTR. all errors are shown # see also http://www.python.org/dev/peps/pep-3151/#select if e[0] not in (errno.EAGAIN, errno.EALREADY, errno.EWOULDBLOCK, errno.EINPROGRESS, errno.EINTR): raise SerialException('read failed: {}'.format(e)) if timeout.expired(): break return bytes(read)