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))
[-------------------------------------------------------------]
/*
Template C code used to produce target Ethercat C code
Copyright (C) 2011-2014: Laurent BESSARD, Edouard TISSERANT
Distributed under the terms of the GNU Lesser General Public License as
published by the Free Software Foundation; either version 2 of the License, or
(at your option) any later version.
See COPYING file for copyrights details.
*/
#include <rtdm/rtdm.h>
#include <native/task.h>
#include <native/timer.h>
#include "ecrt.h"
#include "beremiz.h"
#include "iec_types_all.h"
// declaration of interface variables
%(located_variables_declaration)s
// process data
uint8_t *domain1_pd = NULL;
%(used_pdo_entry_offset_variables_declaration)s
const static ec_pdo_entry_reg_t domain1_regs[] = {
%(used_pdo_entry_configuration)s
{}
};
/*****************************************************************************/
%(pdos_configuration_declaration)s
long long wait_period_ns = 100000LL;
// EtherCAT
static ec_master_t *master = NULL;
static ec_domain_t *domain1 = NULL;
static int first_sent=0;
%(slaves_declaration)s
#define SLOGF(level, format, args...)\
{\
char sbuf[256];\
int slen = snprintf(sbuf , sizeof(sbuf) , format , ##args);\
LogMessage(level, sbuf, slen);\
}
/* Beremiz plugin functions */
int __init_%(location)s(int argc,char **argv)
{
uint32_t abort_code;
size_t result_size;
abort_code = 0;
result_size = 0;
master = ecrt_request_master(%(master_number)d);
if (!master) {
SLOGF(LOG_CRITICAL, "EtherCAT master request failed!");
return -1;
}
if(!(domain1 = ecrt_master_create_domain(master))){
SLOGF(LOG_CRITICAL, "EtherCAT Domain Creation failed!");
goto ecat_failed;
}
// slaves PDO configuration
%(slaves_configuration)s
if (ecrt_domain_reg_pdo_entry_list(domain1, domain1_regs)) {
SLOGF(LOG_CRITICAL, "EtherCAT PDO registration failed!");
goto ecat_failed;
}
ecrt_master_set_send_interval(master, common_ticktime__);
// slaves initialization
%(slaves_initialization)s
// extracting default value for not mapped entry in output PDOs
%(slaves_output_pdos_default_values_extraction)s
if (ecrt_master_activate(master)){
SLOGF(LOG_CRITICAL, "EtherCAT Master activation failed");
goto ecat_failed;
}
if (!(domain1_pd = ecrt_domain_data(domain1))) {
SLOGF(LOG_CRITICAL, "Failed to map EtherCAT process data");
goto ecat_failed;
}
SLOGF(LOG_INFO, "Master %(master_number)d activated.");
first_sent = 0;
return 0;
ecat_failed:
ecrt_release_master(master);
return -1;
}
void __cleanup_%(location)s(void)
{
//release master
ecrt_release_master(master);
first_sent = 0;
}
void __retrieve_%(location)s(void)
{
// receive ethercat
if(first_sent){
ecrt_master_receive(master);
ecrt_domain_process(domain1);
%(retrieve_variables)s
}
}
static RTIME _last_occur=0;
static RTIME _last_publish=0;
RTIME _current_lag=0;
RTIME _max_jitter=0;
static inline RTIME max(RTIME a,RTIME b){return a>b?a:b;}
void __publish_%(location)s(void)
{
%(publish_variables)s
ecrt_domain_queue(domain1);
{
RTIME current_time = rt_timer_read();
// Limit spining max 1/5 of common_ticktime
RTIME maxdeadline = current_time + (common_ticktime__ / 5);
RTIME deadline = _last_occur ?
_last_occur + common_ticktime__ :
current_time + _max_jitter;
if(deadline > maxdeadline) deadline = maxdeadline;
_current_lag = deadline - current_time;
if(_last_publish != 0){
RTIME period = current_time - _last_publish;
if(period > common_ticktime__ )
_max_jitter = max(_max_jitter, period - common_ticktime__);
else
_max_jitter = max(_max_jitter, common_ticktime__ - period);
}
_last_publish = current_time;
_last_occur = current_time;
while(current_time < deadline) {
_last_occur = current_time; //Drift backward by default
current_time = rt_timer_read();
}
if( _max_jitter * 10 < common_ticktime__ && _current_lag < _max_jitter){
//Consuming security margin ?
_last_occur = current_time; //Drift forward
}
}
ecrt_master_send(master);
first_sent = 1;
}