DBR_GR_ENUM monitor updates dont contain enum strings

[Jeff Hill]

From Ken Evans,

     There is a problem when using dbr_gr_enum's or dbr_ctrl_enum's
with the Gateway. If you monitor, they have the enum strings the
first time, but not thereafter. The num_str is 0 after the first
monitor callback.

     I made a test case:

With the Gateway:

48 krypton:simpleCA>O.solaris-sparc/testenum evans:bo01
Nov 08 17:19:10 Search started for evans:bo01
Nov 08 17:19:10 Connection successful
Nov 08 17:19:10 Value is: 0
  no_str=2
     0 Off
     1 On
Nov 08 17:19:10 Value is: 1
  no_str=0
Nov 08 17:19:11 Value is: 0
  no_str=0
Nov 08 17:19:13 Value is: 1
  no_str=0
Nov 08 17:19:14 Value is: 0
  no_str=0
Nov 08 17:19:16 Value is: 1
  no_str=0
Nov 08 17:19:17 Value is: 0
  no_str=0
Nov 08 17:19:19 Value is: 1
  no_str=0
Nov 08 17:19:20 Value is: 0
  no_str=0
Nov 08 17:19:20 All done after 10 sec
49 krypton:simpleCA>

Direct to the IOC:

45 chiron:simpleCA>O.solaris-sparc/testenum evans:bo01
Nov 08 17:22:09 Search started for evans:bo01
Nov 08 17:22:09 Connection successful
Nov 08 17:22:09 Value is: 0
  no_str=2
     0 Off
     1 On
Nov 08 17:22:10 Value is: 1
  no_str=2
     0 Off
     1 On
Nov 08 17:22:11 Value is: 0
  no_str=2
     0 Off
     1 On
Nov 08 17:22:13 Value is: 1
  no_str=2
     0 Off
     1 On
Nov 08 17:22:14 Value is: 0
  no_str=2
     0 Off
     1 On
Nov 08 17:22:16 Value is: 1
  no_str=2
     0 Off
     1 On
Nov 08 17:22:17 Value is: 0
  no_str=2
     0 Off
     1 On
Nov 08 17:22:19 All done after 10 sec
46 chiron:simpleCA>

   This is coming from the callback:

/***************************** valueChangedCB *************************/
static void valueChangedCB(struct event_handler_args args)
{
  /* Print the value */
    if(args.status == ECA_NORMAL && args.dbr) {
 int i;

 struct dbr_gr_enum *dbr=(struct dbr_gr_enum *)args.dbr;
 printf("%s Value is: %hd\\n",timeStamp(),dbr->value);
 printf(" no_str=%hd\\n",dbr->no_str);
 for(i=0; i < dbr->no_str; i++) {
     if(dbr->strs && dbr->strs[i]) {
  printf(" %2d %s\\n",i,dbr->strs[i]);
     } else {
  printf(" %2d NA\\n",i);
     }
 }
    } else {
 printf("%s Bad value\\n",timeStamp());
    }
}

     The whole file is:

--testenum.c------------------------------------------
/* Test dbr_gr_enum problem */

#define TIMEOUT 10.0
#define SCA_OK 1
#define SCA_ERR 0
#define MAX_STRING 40

#include <stdio.h>
#include <stdlib.h>
#include <time.h>
#include <string.h>
#include <cadef.h>

/* Function prototypes */
int main(int argc, char **argv);
static void connectionChangedCB(struct connection_handler_args args);
static void valueChangedCB(struct event_handler_args args);
static char *timeStamp(void);
static int parseCommand(int argc, char **argv);
static void usage(void);

/* Global variables */
int pvSpecified=0;
char name[MAX_STRING];
time_t curTime, startTime;
double timeout=TIMEOUT;
evid pEv;

/***************************** main ***********************************/
int main(int argc, char **argv)
{
    int stat;
    chid pCh;

  /* Parse the command line */
    if(parseCommand(argc,argv) != SCA_OK) exit(1);
    if(!pvSpecified) {
 printf("No PV specified\\n");
 exit(1);
    }

  /* Initialize */
#if 0
    stat=ca_context_create(ca_enable_preemptive_callback);
#else
    stat=ca_context_create(ca_disable_preemptive_callback);
#endif
    if(stat != ECA_NORMAL) {
 printf("ca_context_create failed:\\n%s\\n",ca_message(stat));
 exit(1);
    }

  /* Search */
    stat=ca_create_channel(name,connectionChangedCB,NULL,
      CA_PRIORITY_DEFAULT,&pCh);
    if(stat != ECA_NORMAL) {
 printf("ca_create_channel failed:\\n%s\\n",ca_message(stat));
 exit(1);
    }
    printf("%s Search started for %s\\n",timeStamp(),name);

  /* Wait */
    startTime=curTime;
    ca_pend_event(timeout);
    printf("%s All done after %ld sec\\n",timeStamp(),
      curTime-startTime);

  /* Clear the channel */
    stat=ca_clear_channel(pCh);
    if(stat != ECA_NORMAL) {
 printf("ca_clear_channel failed:\\n%s\\n",ca_message(stat));
    }

  /* Exit */
    ca_context_destroy();
    return(0);
}

/***************************** connectionChangedCB ********************/
static void connectionChangedCB(struct connection_handler_args args)
{
    chid pCh=args.chid;
    int stat;

  /* Branch depending on the state */
    switch (ca_state(pCh)) {
    case cs_conn:
 printf("%s Connection successful\\n",timeStamp());
 if(ca_field_type(pCh) != DBR_ENUM) {
     printf("This program only works with ENUM process variables\\n");
     exit(1);
 }
 stat=ca_create_subscription(DBR_GR_ENUM,1,pCh,
   DBE_VALUE|DBE_LOG|DBE_ALARM,
   valueChangedCB,NULL,&pEv);
 if(stat != ECA_NORMAL) {
     printf("ca_array_get_callback:\\n%s\\n",ca_message(stat));
     exit(1);
 }
 break;
    case cs_never_conn:
 printf("%s Cannot connect\\n",timeStamp());
 break;
    case cs_prev_conn:
 printf("%s Lost connection\\n",timeStamp());
 break;
    case cs_closed:
 printf("%s Connection closed\\n",timeStamp());
    break;
    }
}

/***************************** valueChangedCB *************************/
static void valueChangedCB(struct event_handler_args args)
{
  /* Print the value */
    if(args.status == ECA_NORMAL && args.dbr) {
 int i;

 struct dbr_gr_enum *dbr=(struct dbr_gr_enum *)args.dbr;
 printf("%s Value is: %hd\\n",timeStamp(),dbr->value);
 printf(" no_str=%hd\\n",dbr->no_str);
 for(i=0; i < dbr->no_str; i++) {
     if(dbr->strs && dbr->strs[i]) {
  printf(" %2d %s\\n",i,dbr->strs[i]);
     } else {
  printf(" %2d NA\\n",i);
     }
 }
    } else {
 printf("%s Bad value\\n",timeStamp());
    }
}

/***************************** timeStamp ******************************/
static char *timeStamp(void)
  /* Gets current time and puts it in a static array
   * The calling program should copy it to a safe place
   * e.g. strcpy(savetime,timestamp()); */
{
 static char timeStampStr[16];
 time_t now;
 struct tm *tblock;

 time(&now);
 curTime=now;
 tblock=localtime(&now);
 strftime(timeStampStr,20,"%b %d %H:%M:%S",tblock);

 return timeStampStr;
}

/**************************** parseCommand ********************************/
static int parseCommand(int argc, char **argv)
{
    int i;

    for(i=1; i < argc; i++) {
 if (argv[i][0] == '-') {
     switch(argv[i][1]) {
     case 'h':
  usage();
  exit(0);
     case 't':
  timeout=atof(argv[++i]);
  break;
     default:
  fprintf(stderr,"\\n\\nInvalid option: %s\\n",argv[i]);
  usage();
  return SCA_ERR;
     }
 } else {
     if(!pvSpecified) {
  strncpy(name,argv[i],MAX_STRING);
  name[MAX_STRING-1]='\\0';
  pvSpecified=1;
     } else {
  printf("\\n\\nInvalid option: %s\\n",argv[i]);
  usage();
  return SCA_ERR;
     }
 }
    }
    return SCA_OK;
}

/**************************** usage ***************************************/
static void usage(void)
{
    printf(
      "\\nUsage: testenum [Options] pvname\\n"
      " Connects to pvname and monitors the value\\n"
      "\\n"
      " Options:\\n"
      " -h help This message\\n"
      " -t float Timeout in seconds (Default: %g)\\n",TIMEOUT);
}

Original Mantis Bug: mantis-159
    http://www.aps.anl.gov/epics/mantis/view_bug_page.php?f_id=159

[Jeff Hill (johill-lanl)]

patch was committed to src/gdd/dbMapper.cc
fixed in R3.14.7

[Andrew Johnson (anj)]

R3.14.7 Released