Experimental Physics and
Industrial Control System

Mark Rivers <[email protected]> · Fri, 24 Jul 2015 12:08:35 +0000

The first thing you should do is fix this error:

dbLoadRecords "db/project.db"
Can't set "wafData.INP" to "vmeInput.BINP"
Error at or before ")" in file "db/project.db" line 29

You have a syntax error in line 29 of project.db.

When your application crashed it produced a core dump file.  That is good, since you can then run the gdb debugger on it.  Here is how:

cd to the bin/linux-x86/myExample directory

At the Linux prompt type
gdb ../../bin/linux-x86/myExample core.xxxx
where xxxx is the number of one of the core files in that directory.

At the gdb prompt type
backtrace

That will show you exactly what function, and hopefully what line, was executing when it crashed.

Even more simply you can just put printf() statements at the areas that are likely to be causing the crash, like the call to dbGet().

Mark

________________________________
From: [email protected] [[email protected]] on behalf of ishita bhatia [[email protected]]
Sent: Friday, July 24, 2015 6:57 AM
To: EPICS Tech-Talk
Subject: Segmentation fault(core dumped) Error

Hello,
I have created a device support to fetch data from waveform record and this waveform record gets input from asyn record. When I run ioc I get error as Segmentation fault(core dumped).
kindly suggest how to resolve this error.

[srk@srk VME]$ cd iocBoot/iocmyExample/
[srk@srk iocmyExample]$ ./st.cmd
#!../../bin/linux-x86/myExample
## You may have to change myExample to something else
## everywhere it appears in this file
< envPaths
epicsEnvSet("ARCH","linux-x86")
epicsEnvSet("IOC","iocmyExample")
epicsEnvSet("TOP","/home/srk/VME")
epicsEnvSet("ASYN","/home/srk/EPICS/R3.14.12.1/synApps_5_7/support/asyn-4-21")
epicsEnvSet("CALC","/home/srk/EPICS/R3.14.12.1/synApps_5_7/support/calc-3-2")
epicsEnvSet("EPICS_BASE","/home/srk/EPICS/R3.14.12.1/base")
cd /home/srk/VME
## Register all support components
dbLoadDatabase "dbd/myExample.dbd"
myExample_registerRecordDeviceDriver pdbbase
## initialize port for test serial
drvAsynSerialPortConfigure("L2","/dev/ttyS0",0,0,0)
asynSetOption("L2",-1,"baud","19200")
asynSetOption("L2",-1,"bits","8")
asynSetOption("L2",-1,"parity","none")
asynSetOption("L2",-1,"stop","1")
asynSetOption("L2",-1,"clocal","Y")
## Load record instances
dbLoadTemplate "db/userHost.substitutions"
dbLoadRecords "db/dbSubExample.db", "user=srkHost"
dbLoadRecords "db/project.db"
Can't set "wafData.INP" to "vmeInput.BINP"
Error at or before ")" in file "db/project.db" line 29
## Set this to see messages from mySub
#var mySubDebug 1
## Run this to trace the stages of iocInit
#traceIocInit
cd /home/srk/VME/iocBoot/iocmyExample
iocInit
Starting iocInit
############################################################################
## EPICS R3.14.12.1 $Date: Tue 2011-04-26 15:36:19 -0500$
## EPICS Base built Oct  7 2014
############################################################################
iocRun: All initialization complete
## Start any sequence programs
#seq sncExample, "user=srkHost"
../online_notify.c: CA beacon (send to "127.0.0.1:5065<http://127.0.0.1:5065>") error was "Connection refused"

Value=5
../online_notify.c: CA beacon (send to "127.0.0.1:5065<http://127.0.0.1:5065>") error was "Connection refused"

Value=5
epics>
Value=5

Value=5

Value=5

Value=5
../online_notify.c: CA beacon (send to "127.0.0.1:5065<http://127.0.0.1:5065>") error was "Connection refused"

Value=5

Value=5

Value=5

Value=5

Value=5

Value=5

Value=5

Value=5

Value=5

Value=5
Segmentation fault (core dumped)
[srk@srk iocmyExample]$

db file is as follows:

record(asyn, vmeInput) {
  field(SCAN, "1 second")
  field(DTYP, "asynRecordDevice")
  field(FLNK, "wafData")
  field(PORT, "L2")
  field(TMOD, "Write/Read")
  field(IFACE, "asynOctet")
  field(AOUT, "ST03@U#PKT01!")
  field(OFMT, "ASCII")
  field(NRRD, "80")
  field(IFMT, "Hybrid")
  field(BAUD, "19200")
  field(PRTY, "None")
  field(DBIT, "8")
  field(SBIT, "1")
  field(CNCT, "Connect")
  field(ENBL, "Enable")
}

record(waveform, wafData) {
  field(SCAN, "Passive")
  field(DTYP, "wafsupport")
  field(INP, "vmeInput.BINP")
  field(NELM, "72")
  field(FTVL, "CHAR")
  field(FLNK, "forwardlink")
}

record(ai, analogInput) {
  field(SCAN, ".1 second")
  field(DTYP, "aisupport")
}

DEVICE SUPPORT I have created is as follows:

#include <stdio.h>
#include <string.h>
#include <stddef.h>
#include <math.h>
#include <stdlib.h>

#include "alarm.h"
#include "cvtTable.h"
#include "dbDefs.h"
#include "dbAccess.h"
#include "recGbl.h"
#include "recSup.h"
#include "devSup.h"
#include "link.h"
#include "aiRecord.h"
#include "waveformRecord.h"
#include "epicsExport.h"

//static int v=1;
static int v=2,y=3,z;
//long n;
//char myptr[72];
//struct DBADDR *paddr;

static long read_aiValue();
//static long read_aiValue1();
static long read_waveform();

// structure for ai

struct
 {
long   number;
DEVSUPFUN report;
DEVSUPFUN init;
DEVSUPFUN init_record;
DEVSUPFUN get_ioint_info;
DEVSUPFUN read_aiValue;
DEVSUPFUN special_linconv;
}
devmyai = {
6,
NULL,
NULL,
NULL,
NULL,
read_aiValue,
NULL};
epicsExportAddress(dset,devmyai);

//------------STRUCTURE FOR WAVEFORM---------
struct
{
long   number;
DEVSUPFUN report;
DEVSUPFUN init;
DEVSUPFUN init_record;
DEVSUPFUN get_ioint_info;
DEVSUPFUN read_waveform;
}
devmywaveform = {
     5,
     NULL,
     NULL,
              NULL,
     NULL,
              read_waveform};
epicsExportAddress(dset,devmywaveform);

static long read_aiValue(pai)
struct aiRecord *pai;
{
//static int v=2,y=3,z;
pai->val=(v+y);
z=(v+y);
printf("\nValue=%d\n",z);
return(2);

}

static long read_waveform(pwaf)
struct waveformRecord *pwaf;
{
long int n;
char myptr[100];
struct dbAddr *paddr;
//long status,n;
n = pwaf->nelm;
paddr = dbGetPdbAddrFromLink(&pwaf->inp);
dbGet(paddr,pwaf->ftvl,(void *)myptr,0,&n,NULL);
        //printf("\nstatus=%s\n",myptr);
return 0;
}

Please help me with this error.
Thanks in advance

Experimental Physics and Industrial Control System

Experimental Physics and
Industrial Control System