Experimental Physics and
Industrial Control System

"Mark Rivers" <[email protected]> · Fri, 7 Sep 2007 06:48:46 -0500

This is happening in devAsynInt32.c.  initCommon in that code creates 2 asynUsers. One is used during normal record processing.  The second is used once during iocInit for a "synchronous" read to determine the initial value.  This lets your longout record be initialized to the current value of the hardware if that initial read returns success.

Mark

________________________________

From: [email protected] on behalf of Heinrich du Toit
Sent: Fri 9/7/2007 5:19 AM
To: TechTalk EPICS
Subject: ASYN - weird

Hi

I have an ASYN port.

It registers the DrvUser interface:

I have this function:

asynStatus piDrvUserCreate(void *drvPvt, asynUser *pasynUser,
                                  const char *drvInfo, const char **pptypeName,size_t *psize)
{
  PythonPort *myport = (PythonPort*)drvPvt;
  if (!myport){
    printf("### ERROR - drvPvt = NULL\n");
    return asynError;
  }
  printf("user = %p\n",pasynUser);
  printf("drvUser = %p\n",pasynUser->drvUser);
  PythonUser *myuser = new PythonUser(myport,drvInfo);
  pasynUser->drvUser = myuser;
  return asynSuccess;
}

Now my .db file has:

record(longout,"p0")
{
        field(DTYP,"asynInt32")
        field(OUT,"@asyn(testp) printp")
        field(DESC,"burb")
}

dbl IOC command confirms I have only one record!

Yet output on IOC:

user = 0x80ee96c
drvUser = (nil)
Creating Python User options=printp
user = 0x80eeb24
drvUser = (nil)
Creating Python User options=printp
iocInit: All initialization complete

asynReport confirm that there is only 1 portname testp

I don't get it
Why is CreateUser called twice with different asynUser's ??

I've seen this dual-called behaviour of DrvUser before in my other
drivers. This time I would like to figure it out :)

Thanks in advance!
-Heinrich

Experimental Physics and Industrial Control System

Experimental Physics and
Industrial Control System