recoverserial.py

#!/usr/bin/env python

import logging
import serial
import time
from threading import Lock

log = logging.getLogger("recoverserial")

class RecoverSerial(serial.Serial):

    def log_error(self, e):
        msg = str(e)
        if msg != self.lasterror:
            log.error(msg)
            self.lasterror = msg

    def __init__(self, *args, **kwargs):
        self.object_nr = 0
        self.recover_lock = Lock()
        self.lasterror = None
        while True:
            try:
                return super(RecoverSerial, self).__init__(*args, **kwargs)
            except serial.SerialException as e:
                self.log_error(e)
                time.sleep(1)

    def recover(self, nr):
        self.recover_lock.acquire()
        while nr == self.object_nr:
            time.sleep(1)
            try:
                self.close()
                self.open()
                self.object_nr += 1
            except serial.SerialException as e:
                self.log_error(e)
                pass

        self.recover_lock.release()

    def readline(self, *args, **kwargs):
        nr = self.object_nr
        try:
            return super(RecoverSerial, self).readline(*args, **kwargs)
        except serial.SerialException as e:
            self.log_error(e)
            self.recover(nr)
            return ''

    def write(self, *args, **kwargs):
        while True:
            nr = self.object_nr
            try:
                return super(RecoverSerial, self).write(*args, **kwargs)
            except serial.SerialException as e:
                self.log_error(e)
                self.recover(nr)