3 import ctypes,time,re

    52 

    53 KMSGPollThread=None

    54 StopKMSGThread=False

    55 def KMSGPollThreadProc():

    56     """

    57     Logs Kernel messages starting with EtherCAT

    58     Uses GLibc wrapper to Linux syscall "klogctl"

    59     Last 4 KB are polled, and lines compared to last 

    60     captured line to detect new lines

    61     """

    62     global StopKMSGThread

    63     libc=ctypes.CDLL("libc.so.6")

    64     klog = libc.klogctl

    65     klog.argtypes = [ctypes.c_int, ctypes.c_char_p, ctypes.c_int]

    66     klog.restype = ctypes.c_int

    67     s=ctypes.create_string_buffer(4*1024)

    68     last = None

    69     while not StopKMSGThread:

    70         l = klog(3,s,len(s)-1)

    71         log = s.value[:l-1]

    72         if last :

    73             log = log.rpartition(last)[2]

    74         if log : 

    75             last = log.rpartition('\n')[2]

    76             for msg in re.findall(r'<\d>\[\s*\d*\.\d*\]\s*(EtherCAT\s*.*)$',

    77                                   log, re.MULTILINE):

    78                 PLCObject.LogMessage(msg)

    79         time.sleep(0.5) 

    80 

    81 def _runtime_etherlab_init():

    82     global KMSGPollThread, StopKMSGThread

    83     StopKMSGThread = False

    84     KMSGPollThread = Thread(target = KMSGPollThreadProc)

    85     KMSGPollThread.start()

    86 

    87 def _runtime_etherlab_cleanup():

    88     global KMSGPollThread, StopKMSGThread

    89     StopKMSGThread = True

    90     KMSGPollThread = None

    91 

    92