RE: Filtering messages print on the IOC shell console

[Mark Rivers via Tech-talk <tech-talk at aps.anl.gov>]

Hi Martin,

> There is only one IOC shell thread. Assuming that IOC shell commands are executed in a synchronous way there is no risk of corrupting messages printed by printf 
> as long as you stick to Andrews rule and use printf only in IOC shell commands.

Here is an example of garbled output coming simply from the dbLoadTemplate command.  It happens that DAC.template is trying to load a non-existent singleDAC.db file.  Note that the messages from dbLoadTemplate are garbled in with subsequent comments and commands in the startup script.  Is this because dbLoadTemplate is actually loading the database file in another thread?  If not why is it garbled?

**********************************************
initIpUnidig("Unidig1", 0, 1, 100, 116, 0xffffff, 0xffffff)
value = 0 = 0x0
dbLoadTemplate "ipUnidig.substitutions"
value = 0 = 0x0

# Initialize Systran DAC
# initDAC128V(char *portName, int carrier, int slot)
# portName  = name to give this asyn port
# carrier     = IPAC carrier number (0, 1, etc.)
# slot        = IPAC slot (0,1,2,3, etc.)
initDAC128V("DAC1", 0, 3)
value = 0 = 0x0
dbLoadTemplate "DAC.template"
filename="value = ../dbStatic/0dbLexRoutines.c" li = ne number=264
S_n0xfsLib_NFSERR_NOENT0

 dbRead open Acromag IP-330 ADC
home/epe /corvette/# initIp330(
-9/db/singlac128V-2#   const char *portName, int carrier, int slot,
eDAC.db
filename="../dbStapeString, const char *rangeString,
" line exRoutines.c#   int firstChan, int lastChan,
number=264
_NFSsLib#   int intVec)
ening file /corv op# portName    = name to give this asyn port
el/dac128V-pics/dev# carrier     = IPAC carrier number (0, 1, etc.)
2-9/db/singleDAC.db# slot        = IPAC slot (0,1,2,3, etc.)

filename="../dbS"D" or "S" for differential or single-ended
.c" linbLexRoutines# rangeString = "-5to5","-10to10","0to5", or "0to10"
e number=264
ib_NFSERR_NOENT       This value must match hardware setting selected
 /cord opening file# firstChan   = first channel to be digitized.  This must be in the range:
vette/home/epics/de#               0 to 31 (single-ended)
il/dac128V-2-9/db/s#               0 to 15 (differential)
ngleDAC.db
filastChan    = last channel to be digitized
dbLexRo../dbStatic/# intVec        Interrupt vector
er=264.c" line numbinitIp330("Ip330_1",0,2,"D","-5to5",0,15,120)
S_nfsLi
**********************************************


Mark


-----Original Message-----
From: Tech-talk <tech-talk-bounces at aps.anl.gov> On Behalf Of Konrad, Martin via Tech-talk
Sent: Thursday, March 26, 2020 5:26 PM
To: J. Lewis Muir <jlmuir at imca-cat.org>; Johnson, Andrew N. <anj at anl.gov>
Cc: EPICS tech-talk <tech-talk at aps.anl.gov>
Subject: Re: Filtering messages print on the IOC shell console

Hi Lewis,
> A problem I often see on VxWorks VME crate IOC consoles is that output 
> is corrupted.  It looks as if two or more threads or processes are 
> writing to the console at the same time.  Does your suggestion about 
> where you consider it appropriate to use printf and fprintf include 
> this situation?  How can this be avoided?
There is only one IOC shell thread. Assuming that IOC shell commands are executed in a synchronous way there is no risk of corrupting messages printed by printf as long as you stick to Andrews rule and use printf only in IOC shell commands.

Cheers,

Martin

--
Martin Konrad
Facility for Rare Isotope Beams
Michigan State University
640 South Shaw Lane
East Lansing, MI 48824-1321, USA
Tel. 517-908-7253
Email: konrad at frib.msu.edu