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#!/usr/bin/env python

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# -*- coding: utf-8 -*-

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# This file is part of Beremiz runtime.

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#

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# Copyright (C) 2007: Edouard TISSERANT and Laurent BESSARD

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#

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# See COPYING.Runtime file for copyrights details.

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#

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# This library is free software; you can redistribute it and/or

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# modify it under the terms of the GNU Lesser General Public

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# License as published by the Free Software Foundation; either

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# version 2.1 of the License, or (at your option) any later version.

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# This library is distributed in the hope that it will be useful,

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# but WITHOUT ANY WARRANTY; without even the implied warranty of

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# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU

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# Lesser General Public License for more details.

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# You should have received a copy of the GNU Lesser General Public

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# License along with this library; if not, write to the Free Software

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# Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA

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from __future__ import absolute_import

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from threading import Thread, Lock, Semaphore, Event, Condition

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import ctypes

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import os

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import sys

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import traceback

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from time import time

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import _ctypes  # pylint: disable=wrong-import-order

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import Pyro.core as pyro

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import six

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from runtime.typemapping import TypeTranslator

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from runtime.loglevels import LogLevelsDefault, LogLevelsCount

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from runtime import PlcStatus

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if os.name in ("nt", "ce"):

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    dlopen = _ctypes.LoadLibrary

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    dlclose = _ctypes.FreeLibrary

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elif os.name == "posix":

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    dlopen = _ctypes.dlopen

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    dlclose = _ctypes.dlclose

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def get_last_traceback(tb):

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    while tb.tb_next:

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        tb = tb.tb_next

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    return tb

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lib_ext = {

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    "linux2": ".so",

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    "win32":  ".dll",

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}.get(sys.platform, "")

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def PLCprint(message):

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    sys.stdout.write("PLCobject : "+message+"\n")

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    sys.stdout.flush()

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class job(object):

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    """

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    job to be executed by a worker

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    """

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    def __init__(self, call, *args, **kwargs):

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        self.job = (call, args, kwargs)

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        self.result = None

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        self.success = False

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        self.exc_info = None

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    def do(self):

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        """

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        do the job by executing the call, and deal with exceptions

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        """

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        try:

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            call, args, kwargs = self.job

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            self.result = call(*args, **kwargs)

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            self.success = True

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        except Exception:

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            self.success = False

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            self.exc_info = sys.exc_info()

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class worker(object):

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    """

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    serialize main thread load/unload of PLC shared objects

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    """

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    def __init__(self):

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        # Only one job at a time

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        self._finish = False

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        self._threadID = None

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        self.mutex = Lock()

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        self.todo = Condition(self.mutex)

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        self.done = Condition(self.mutex)

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        self.free = Condition(self.mutex)

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        self.job = None

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    def runloop(self, *args, **kwargs):

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        """

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        meant to be called by worker thread (blocking)

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        """

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        if args or kwargs:

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            job(*args, **kwargs).do()

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            # result is ignored

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        self.mutex.acquire()

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        while not self._finish:

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            self.todo.wait()

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            if self.job is not None:

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                self.job.do()

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                self.done.notify()

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            else:

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                self.free.notify()

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        self.mutex.release()

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    def call(self, *args, **kwargs):

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        """

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        creates a job, execute it in worker thread, and deliver result.

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        if job execution raise exception, re-raise same exception

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        meant to be called by non-worker threads, but this is accepted.

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        blocking until job done

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        """

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        _job = job(*args, **kwargs)

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            # if caller is worker thread execute immediately

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            _job.do()

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        else:

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            # otherwise notify and wait for completion

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            self.mutex.acquire()

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            while self.job is not None:

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                self.free.wait()

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            self.job = _job

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            self.todo.notify()

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            self.done.wait()

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            _job = self.job

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            self.job = None

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            self.mutex.release()

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        if _job.success:

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            return _job.result

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        else:

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            exc_type = _job.exc_info[0]

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            exc_value = _job.exc_info[1]

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            exc_traceback = _job.exc_info[2]

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            six.reraise(exc_type, exc_value, exc_traceback)

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    def quit(self):

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        """

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        unblocks main thread, and terminate execution of runloop()

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        """

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        # mark queue

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        self._finish = True

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        self.mutex.acquire()

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        self.job = None

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        self.todo.notify()

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        self.mutex.release()

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MainWorker = worker()

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def RunInMain(func):

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    def func_wrapper(*args, **kwargs):

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        return MainWorker.call(func, *args, **kwargs)

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    return func_wrapper

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class PLCObject(pyro.ObjBase):

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    def __init__(self, server):

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        pyro.ObjBase.__init__(self)

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        self.evaluator = server.evaluator

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        self.argv = [server.workdir] + server.argv  # force argv[0] to be "path" to exec...

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        self.workingdir = server.workdir

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        self.PLCStatus = PlcStatus.Empty

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        self.PLClibraryHandle = None

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        self.PLClibraryLock = Lock()

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        self.DummyIteratorLock = None

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        # Creates fake C funcs proxies

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        self._InitPLCStubCalls()

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        self.daemon = server.daemon

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        self.statuschange = server.statuschange

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        self.hmi_frame = None

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        self.pyruntimevars = server.pyruntimevars

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        self._loading_error = None

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        self.python_runtime_vars = None

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        self.TraceThread = None

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        self.TraceLock = Lock()

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        self.Traces = []

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    # First task of worker -> no @RunInMain

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    def AutoLoad(self):

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        # Get the last transfered PLC

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        try:

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            self.CurrentPLCFilename = open(

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                self._GetMD5FileName(),

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                "r").read().strip() + lib_ext

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            if self.LoadPLC():

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                self.PLCStatus = PlcStatus.Stopped

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        except Exception:

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            self.PLCStatus = PlcStatus.Empty

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            self.CurrentPLCFilename = None

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    def StatusChange(self):

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        if self.statuschange is not None:

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            for callee in self.statuschange:

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                callee(self.PLCStatus)

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    @RunInMain

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    def LogMessage(self, *args):

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        if len(args) == 2:

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            level, msg = args

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        else:

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            level = LogLevelsDefault

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            msg, = args

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        PLCprint(msg)

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        if self._LogMessage is not None:

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            return self._LogMessage(level, msg, len(msg))

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        return None

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    @RunInMain

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    def ResetLogCount(self):

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        if self._ResetLogCount is not None:

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            self._ResetLogCount()

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    # used internaly

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    def GetLogCount(self, level):

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        if self._GetLogCount is not None:

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            return int(self._GetLogCount(level))

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        elif self._loading_error is not None and level == 0:

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            return 1

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    @RunInMain

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    def GetLogMessage(self, level, msgid):

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        tick = ctypes.c_uint32()

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        tv_sec = ctypes.c_uint32()

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        tv_nsec = ctypes.c_uint32()

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        if self._GetLogMessage is not None:

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            maxsz = len(self._log_read_buffer)-1

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            sz = self._GetLogMessage(level, msgid,

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                                     self._log_read_buffer, maxsz,

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                                     ctypes.byref(tick),

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                                     ctypes.byref(tv_sec),

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                                     ctypes.byref(tv_nsec))

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            if sz and sz <= maxsz:

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                self._log_read_buffer[sz] = '\x00'

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                return self._log_read_buffer.value, tick.value, tv_sec.value, tv_nsec.value

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        elif self._loading_error is not None and level == 0:

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            return self._loading_error, 0, 0, 0

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        return None

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    def _GetMD5FileName(self):

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        return os.path.join(self.workingdir, "lasttransferedPLC.md5")

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    def _GetLibFileName(self):

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        return os.path.join(self.workingdir, self.CurrentPLCFilename)

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    def _LoadPLC(self):

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        """

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        Load PLC library

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        Declare all functions, arguments and return values

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        """

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        md5 = open(self._GetMD5FileName(), "r").read()

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        self.PLClibraryLock.acquire()

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        try:

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            self._PLClibraryHandle = dlopen(self._GetLibFileName())

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            self.PLClibraryHandle = ctypes.CDLL(self.CurrentPLCFilename, handle=self._PLClibraryHandle)

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            self.PLC_ID = ctypes.c_char_p.in_dll(self.PLClibraryHandle, "PLC_ID")

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            if len(md5) == 32:

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                self.PLC_ID.value = md5

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            self._startPLC = self.PLClibraryHandle.startPLC

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            self._startPLC.restype = ctypes.c_int

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            self._startPLC.argtypes = [ctypes.c_int, ctypes.POINTER(ctypes.c_char_p)]

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            self._stopPLC_real = self.PLClibraryHandle.stopPLC

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            self._stopPLC_real.restype = None

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            self._PythonIterator = getattr(self.PLClibraryHandle, "PythonIterator", None)

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            if self._PythonIterator is not None:

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                self._PythonIterator.restype = ctypes.c_char_p

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                self._PythonIterator.argtypes = [ctypes.c_char_p, ctypes.POINTER(ctypes.c_void_p)]

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                self._stopPLC = self._stopPLC_real

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            else:

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                # If python confnode is not enabled, we reuse _PythonIterator

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                # as a call that block pythonthread until StopPLC

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                self.PlcStopping = Event()

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                def PythonIterator(res, blkid):

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                    self.PlcStopping.clear()

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                    self.PlcStopping.wait()

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                    return None

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                self._PythonIterator = PythonIterator

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                def __StopPLC():

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                    self._stopPLC_real()

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                    self.PlcStopping.set()

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                self._stopPLC = __StopPLC

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            self._ResetDebugVariables = self.PLClibraryHandle.ResetDebugVariables

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            self._ResetDebugVariables.restype = None

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            self._RegisterDebugVariable = self.PLClibraryHandle.RegisterDebugVariable

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            self._RegisterDebugVariable.restype = None

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            self._RegisterDebugVariable.argtypes = [ctypes.c_int, ctypes.c_void_p]

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            self._FreeDebugData = self.PLClibraryHandle.FreeDebugData

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            self._FreeDebugData.restype = None

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            self._GetDebugData = self.PLClibraryHandle.GetDebugData

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            self._GetDebugData.restype = ctypes.c_int

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            self._GetDebugData.argtypes = [ctypes.POINTER(ctypes.c_uint32), ctypes.POINTER(ctypes.c_uint32), ctypes.POINTER(ctypes.c_void_p)]

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            self._suspendDebug = self.PLClibraryHandle.suspendDebug

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            self._suspendDebug.restype = ctypes.c_int

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            self._suspendDebug.argtypes = [ctypes.c_int]

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            self._resumeDebug = self.PLClibraryHandle.resumeDebug

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            self._resumeDebug.restype = None

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            self._ResetLogCount = self.PLClibraryHandle.ResetLogCount

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            self._ResetLogCount.restype = None

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            self._GetLogCount = self.PLClibraryHandle.GetLogCount

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            self._GetLogCount.restype = ctypes.c_uint32

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            self._GetLogCount.argtypes = [ctypes.c_uint8]

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            self._LogMessage = self.PLClibraryHandle.LogMessage

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            self._LogMessage.restype = ctypes.c_int

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            self._LogMessage.argtypes = [ctypes.c_uint8, ctypes.c_char_p, ctypes.c_uint32]

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            self._log_read_buffer = ctypes.create_string_buffer(1 << 14)  # 16K

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            self._GetLogMessage = self.PLClibraryHandle.GetLogMessage

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            self._GetLogMessage.restype = ctypes.c_uint32

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            self._GetLogMessage.argtypes = [ctypes.c_uint8, ctypes.c_uint32, ctypes.c_char_p, ctypes.c_uint32, ctypes.POINTER(ctypes.c_uint32), ctypes.POINTER(ctypes.c_uint32), ctypes.POINTER(ctypes.c_uint32)]

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            self._loading_error = None

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        except Exception:

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            self._loading_error = traceback.format_exc()

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            PLCprint(self._loading_error)

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            return False

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        finally:

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            self.PLClibraryLock.release()

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        return True

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    @RunInMain

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    def LoadPLC(self):

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        res = self._LoadPLC()

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        if res:

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            self.PythonRuntimeInit()

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        else:

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            self._FreePLC()

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        return res

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    @RunInMain

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    def UnLoadPLC(self):

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        self.PythonRuntimeCleanup()

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        self._FreePLC()

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    def _InitPLCStubCalls(self):

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        """

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        create dummy C func proxies

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        """

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        self._startPLC = lambda x, y: None

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        self._stopPLC = lambda: None

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        self._ResetDebugVariables = lambda: None

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        self._RegisterDebugVariable = lambda x, y: None

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        self._IterDebugData = lambda x, y: None

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        self._FreeDebugData = lambda: None

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        self._GetDebugData = lambda: -1

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        self._suspendDebug = lambda x: -1

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        self._resumeDebug = lambda: None

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        self._PythonIterator = lambda: ""

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        self._GetLogCount = None

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        self._LogMessage = None

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        self._GetLogMessage = None

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        self._PLClibraryHandle = None

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        self.PLClibraryHandle = None

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    def _FreePLC(self):

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        """

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        Unload PLC library.

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        This is also called by __init__ to create dummy C func proxies

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        """

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        self.PLClibraryLock.acquire()

   399

        try:

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            # Unload library explicitely

   401

            if getattr(self, "_PLClibraryHandle", None) is not None:

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                dlclose(self._PLClibraryHandle)

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   404

            # Forget all refs to library

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            self._InitPLCStubCalls()

   406

   407

        finally:

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            self.PLClibraryLock.release()

   409

   410

        return False

   411

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    def PythonRuntimeCall(self, methodname):

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        """

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        Calls init, start, stop or cleanup method provided by

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        runtime python files, loaded when new PLC uploaded

   416

        """

   417

        for method in self.python_runtime_vars.get("_runtime_%s" % methodname, []):

   418

            _res, exp = self.evaluator(method)

   419

            if exp is not None:

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                self.LogMessage(0, '\n'.join(traceback.format_exception(*exp)))

   421

   422

    # used internaly

   423

    def PythonRuntimeInit(self):

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        MethodNames = ["init", "start", "stop", "cleanup"]

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        self.python_runtime_vars = globals().copy()

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        self.python_runtime_vars.update(self.pyruntimevars)

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        parent = self

   428

   429

        class PLCSafeGlobals(object):

   430

            def __getattr__(self, name):

   431

                try:

   432

                    t = parent.python_runtime_vars["_"+name+"_ctype"]

   433

                except KeyError:

   434

                    raise KeyError("Try to get unknown shared global variable : %s" % name)

   435

                v = t()

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                parent.python_runtime_vars["_PySafeGetPLCGlob_"+name](ctypes.byref(v))

   437

                return parent.python_runtime_vars["_"+name+"_unpack"](v)

   438

   439

            def __setattr__(self, name, value):

   440

                try:

   441

                    t = parent.python_runtime_vars["_"+name+"_ctype"]

   442

                except KeyError:

   443

                    raise KeyError("Try to set unknown shared global variable : %s" % name)

   444

                v = parent.python_runtime_vars["_"+name+"_pack"](t, value)

   445

                parent.python_runtime_vars["_PySafeSetPLCGlob_"+name](ctypes.byref(v))

   446

   447

        self.python_runtime_vars.update({

   448

            "PLCGlobals":     PLCSafeGlobals(),

   449

            "WorkingDir":     self.workingdir,

   450

            "PLCObject":      self,

   451

            "PLCBinary":      self.PLClibraryHandle,

   452

            "PLCGlobalsDesc": []})

   453

   454

        for methodname in MethodNames:

   455

            self.python_runtime_vars["_runtime_%s" % methodname] = []

   456

   457

        try:

   458

            filenames = os.listdir(self.workingdir)

   459

            filenames.sort()

   460

            for filename in filenames:

   461

                name, ext = os.path.splitext(filename)

   462

                if name.upper().startswith("RUNTIME") and ext.upper() == ".PY":

   463

                    execfile(os.path.join(self.workingdir, filename), self.python_runtime_vars)

   464

                    for methodname in MethodNames:

   465

                        method = self.python_runtime_vars.get("_%s_%s" % (name, methodname), None)

   466

                        if method is not None:

   467

                            self.python_runtime_vars["_runtime_%s" % methodname].append(method)

   468

        except Exception:

   469

            self.LogMessage(0, traceback.format_exc())

   470

            raise

   471

   472

        self.PythonRuntimeCall("init")

   473

   474

    # used internaly

   475

    def PythonRuntimeCleanup(self):

   476

        if self.python_runtime_vars is not None:

   477

            self.PythonRuntimeCall("cleanup")

   478

   479

        self.python_runtime_vars = None

   480