beremiz

Dirty fix for error '_object_has_no_attribute_'getSlave' in EtherCAT extension

2018-08-10, Andrey Skvortsov
a3ac46366b86
Dirty fix for error '_object_has_no_attribute_'getSlave' in EtherCAT extension

traceback:
File "/home/developer/WorkData/PLC/beremiz/beremiz/IDEFrame.py", line 1433, in OnPouSelectedChanged
window.RefreshView()
File "/home/developer/WorkData/PLC/beremiz/beremiz/etherlab/ConfigEditor.py", line 837, in RefreshView
self.RefreshProcessVariables()
File "/home/developer/WorkData/PLC/beremiz/beremiz/etherlab/ConfigEditor.py", line 886, in RefreshProcessVariables
slaves = self.Controler.GetSlaves(**self.CurrentNodesFilter)
File "/home/developer/WorkData/PLC/beremiz/beremiz/etherlab/EthercatMaster.py", line 341, in GetSlaves
for slave in self.Config.getConfig().getSlave():
:_'lxml.etree._Element'_object_has_no_attribute_'getSlave'

Steps to reproduce problem:

- Add new EtherCAT master
- Add new EthercatNode to the master
- double click on


this is looks like dirty hack to fix strange problem with initial[0]
changing its type after returning from _init_ method to lxml.etree._Element
As a result all methods generated by class factory are lost.

For example, in function initMethod initial[0].__class__ points to
xmlclass.xmlclass.Config. After map(self.append, initial)
self.Config.__class__ is 'xmlclass.xmlclass.Config' as well.
But after returning from initMethod (_init) in CreateElement
self.Config.__class__ has changed to lxml.etree._Element.


I've noticed similar behavior if copy/deepcopy is used for any child
of etree.ElementBase. See simple example below.
[-------------------------------------------------------------]
#!/usr/bin/python

from __future__ import print_function
from lxml import etree
import copy

class DefaultElementClass(etree.ElementBase):
def getLocalTag(self):
return etree.QName(self.tag).localname


def printInformation(x):
print(x, x.__class__, "getLocalTag" in dir(x))


a = DefaultElementClass()
printInformation(a)

#
printInformation(copy.copy(a))
printInformation(copy.deepcopy(a))
[-------------------------------------------------------------]
/**
* Linux specific code
**/
#include <stdio.h>
#include <string.h>
#include <time.h>
#include <signal.h>
#include <stdlib.h>
#include <pthread.h>
#include <locale.h>
#include <semaphore.h>
static sem_t Run_PLC;
long AtomicCompareExchange(long* atomicvar,long compared, long exchange)
{
return __sync_val_compare_and_swap(atomicvar, compared, exchange);
}
long long AtomicCompareExchange64(long long* atomicvar, long long compared, long long exchange)
{
return __sync_val_compare_and_swap(atomicvar, compared, exchange);
}
void PLC_GetTime(IEC_TIME *CURRENT_TIME)
{
struct timespec tmp;
clock_gettime(CLOCK_REALTIME, &tmp);
CURRENT_TIME->tv_sec = tmp.tv_sec;
CURRENT_TIME->tv_nsec = tmp.tv_nsec;
}
void PLC_timer_notify(sigval_t val)
{
PLC_GetTime(&__CURRENT_TIME);
sem_post(&Run_PLC);
}
timer_t PLC_timer;
void PLC_SetTimer(unsigned long long next, unsigned long long period)
{
struct itimerspec timerValues;
/*
printf("SetTimer(%lld,%lld)\n",next, period);
*/
memset (&timerValues, 0, sizeof (struct itimerspec));
{
#ifdef __lldiv_t_defined
lldiv_t nxt_div = lldiv(next, 1000000000);
lldiv_t period_div = lldiv(period, 1000000000);
timerValues.it_value.tv_sec = nxt_div.quot;
timerValues.it_value.tv_nsec = nxt_div.rem;
timerValues.it_interval.tv_sec = period_div.quot;
timerValues.it_interval.tv_nsec = period_div.rem;
#else
timerValues.it_value.tv_sec = next / 1000000000;
timerValues.it_value.tv_nsec = next % 1000000000;
timerValues.it_interval.tv_sec = period / 1000000000;
timerValues.it_interval.tv_nsec = period % 1000000000;
#endif
}
timer_settime (PLC_timer, 0, &timerValues, NULL);
}
//
void catch_signal(int sig)
{
// signal(SIGTERM, catch_signal);
signal(SIGINT, catch_signal);
printf("Got Signal %d\n",sig);
exit(0);
}
static unsigned long __debug_tick;
pthread_t PLC_thread;
static pthread_mutex_t python_wait_mutex = PTHREAD_MUTEX_INITIALIZER;
static pthread_mutex_t python_mutex = PTHREAD_MUTEX_INITIALIZER;
static pthread_mutex_t debug_wait_mutex = PTHREAD_MUTEX_INITIALIZER;
static pthread_mutex_t debug_mutex = PTHREAD_MUTEX_INITIALIZER;
int PLC_shutdown = 0;
int ForceSaveRetainReq(void) {
return PLC_shutdown;
}
void PLC_thread_proc(void *arg)
{
while (!PLC_shutdown) {
sem_wait(&Run_PLC);
__run();
}
pthread_exit(0);
}
#define maxval(a,b) ((a>b)?a:b)
int startPLC(int argc,char **argv)
{
struct sigevent sigev;
setlocale(LC_NUMERIC, "C");
PLC_shutdown = 0;
sem_init(&Run_PLC, 0, 0);
pthread_create(&PLC_thread, NULL, (void*) &PLC_thread_proc, NULL);
memset (&sigev, 0, sizeof (struct sigevent));
sigev.sigev_value.sival_int = 0;
sigev.sigev_notify = SIGEV_THREAD;
sigev.sigev_notify_attributes = NULL;
sigev.sigev_notify_function = PLC_timer_notify;
pthread_mutex_init(&debug_wait_mutex, NULL);
pthread_mutex_init(&debug_mutex, NULL);
pthread_mutex_init(&python_wait_mutex, NULL);
pthread_mutex_init(&python_mutex, NULL);
pthread_mutex_lock(&debug_wait_mutex);
pthread_mutex_lock(&python_wait_mutex);
timer_create (CLOCK_MONOTONIC, &sigev, &PLC_timer);
if( __init(argc,argv) == 0 ){
PLC_SetTimer(common_ticktime__,common_ticktime__);
/* install signal handler for manual break */
signal(SIGINT, catch_signal);
}else{
return 1;
}
return 0;
}
int TryEnterDebugSection(void)
{
if (pthread_mutex_trylock(&debug_mutex) == 0){
/* Only enter if debug active */
if(__DEBUG){
return 1;
}
pthread_mutex_unlock(&debug_mutex);
}
return 0;
}
void LeaveDebugSection(void)
{
pthread_mutex_unlock(&debug_mutex);
}
int stopPLC()
{
/* Stop the PLC */
PLC_shutdown = 1;
sem_post(&Run_PLC);
PLC_SetTimer(0,0);
pthread_join(PLC_thread, NULL);
sem_destroy(&Run_PLC);
timer_delete (PLC_timer);
__cleanup();
pthread_mutex_destroy(&debug_wait_mutex);
pthread_mutex_destroy(&debug_mutex);
pthread_mutex_destroy(&python_wait_mutex);
pthread_mutex_destroy(&python_mutex);
return 0;
}
extern unsigned long __tick;
int WaitDebugData(unsigned long *tick)
{
int res;
if (PLC_shutdown) return 1;
/* Wait signal from PLC thread */
res = pthread_mutex_lock(&debug_wait_mutex);
*tick = __debug_tick;
return res;
}
/* Called by PLC thread when debug_publish finished
* This is supposed to unlock debugger thread in WaitDebugData*/
void InitiateDebugTransfer()
{
/* remember tick */
__debug_tick = __tick;
/* signal debugger thread it can read data */
pthread_mutex_unlock(&debug_wait_mutex);
}
int suspendDebug(int disable)
{
/* Prevent PLC to enter debug code */
pthread_mutex_lock(&debug_mutex);
/*__DEBUG is protected by this mutex */
__DEBUG = !disable;
if (disable)
pthread_mutex_unlock(&debug_mutex);
return 0;
}
void resumeDebug(void)
{
__DEBUG = 1;
/* Let PLC enter debug code */
pthread_mutex_unlock(&debug_mutex);
}
/* from plc_python.c */
int WaitPythonCommands(void)
{
/* Wait signal from PLC thread */
return pthread_mutex_lock(&python_wait_mutex);
}
/* Called by PLC thread on each new python command*/
void UnBlockPythonCommands(void)
{
/* signal debugger thread it can read data */
pthread_mutex_unlock(&python_wait_mutex);
}
int TryLockPython(void)
{
return pthread_mutex_trylock(&python_mutex) == 0;
}
void UnLockPython(void)
{
pthread_mutex_unlock(&python_mutex);
}
void LockPython(void)
{
pthread_mutex_lock(&python_mutex);
}