targets/plc_main_head.c
author Andrey Skvortsov <andrej.skvortzov@gmail.com>
Thu, 28 Apr 2016 13:05:57 +0300
changeset 1507 d7f474d10210
parent 1463 de311ffe3961
child 1981 d0718654d9b0
permissions -rw-r--r--
fix issue with sometimes wrong return code of ProcessLogger


As a result of wrong return code Beremiz gives folowing traceback:
Traceback (most recent call last):
File "./Beremiz.py", line 850, in OnMenu
getattr(self.CTR, method)()
File "/home/developer/WorkData/PLC/beremiz/beremiz/ProjectController.py", line 925, in _Build
IECGenRes = self._Generate_SoftPLC()
File "/home/developer/WorkData/PLC/beremiz/beremiz/ProjectController.py", line 568, in _Generate_SoftPLC
return self._Compile_ST_to_SoftPLC()
File "/home/developer/WorkData/PLC/beremiz/beremiz/ProjectController.py", line 661, in _Compile_ST_to_SoftPLC
C_files.remove("POUS.c")
ValueError: list.remove(x): x not in list

The problem is that both threads (for reading stdout and stderr) call self.Proc.poll(),
that updates internal returncode field. This call is done without any locking and the first thread gets correct result,
but other gets 0 as retval. If 0 gets thread, that afterwards calls callback finish, then wrong return code is returned
to the parent. Now only the thread with a callback polls for the return code, other thread just checked local value.

Additionally function spin() waits now until all threads finish reading their pipes, so the results are always correct.
/**
 * Head of code common to all C targets
 **/

#include "beremiz.h"
#include <string.h>
/*
 * Prototypes of functions provided by generated C softPLC
 **/
void config_run__(unsigned long tick);
void config_init__(void);

/*
 * Prototypes of functions provided by generated target C code
 * */
long long AtomicCompareExchange64(long long*, long long, long long);
void __init_debug(void);
void __cleanup_debug(void);
/*void __retrieve_debug(void);*/
void __publish_debug(void);

/*
 *  Variables used by generated C softPLC and plugins
 **/
IEC_TIME __CURRENT_TIME;
IEC_BOOL __DEBUG = 0;
unsigned long __tick = 0;
char *PLC_ID = NULL;

/*
 *  Variable generated by C softPLC and plugins
 **/
extern unsigned long greatest_tick_count__;

/* Help to quit cleanly when init fail at a certain level */
static int init_level = 0;

/*
 * Prototypes of functions exported by plugins
 **/
%(calls_prototypes)s

/*
 * Retrieve input variables, run PLC and publish output variables
 **/
void __run(void)
{
    __tick++;
    if (greatest_tick_count__)
        __tick %%= greatest_tick_count__;

    %(retrieve_calls)s

    /*__retrieve_debug();*/

    config_run__(__tick);

    __publish_debug();

    %(publish_calls)s

}

/*
 * Initialize variables according to PLC's default values,
 * and then init plugins with that values
 **/
int __init(int argc,char **argv)
{
    int res = 0;
    init_level = 0;
    
    /* Effective tick time with 1ms default value */
    if(!common_ticktime__)
        common_ticktime__ = 1000000;

    config_init__();
    __init_debug();
    %(init_calls)s
    return res;
}
/*
 * Calls plugin cleanup proc.
 **/
void __cleanup(void)
{
    %(cleanup_calls)s
    __cleanup_debug();
}

void PLC_GetTime(IEC_TIME *CURRENT_TIME);
void PLC_SetTimer(unsigned long long next, unsigned long long period);