Experimental Physics and
Industrial Control System

Dirk Zimoch <[email protected]> · Mon, 26 Aug 2013 09:36:36 +0200

Hello Nalaka,

I do not know if this causes your problem, but some recent

implementations of Tcl have a "feature" to be "thread aware". The idea

was to make sure that different posix threads cannot confuse the

inherently single threaded Tcl interpreter. However a side effect I have

seen was that CA monitors did not work any more as expected because the

monitor callback runs in a different thread.

I have first seen this behavior in Tcl 8.4. There you could have the

option to compile the interpreter "not thread aware". But at least

Redhad used the "thread aware" variant in their distribution. With Tcl

8.5 I got the impression things went worse but I am sot sure about this.

However, I have not seen this "feature" to segvfault the interpreter,

only not to serve monitor updates.

Dirk

On 25.08.2013 09:03, nalaka samarasinghe wrote:

Hi All,

I am using et_wish for control system implementation and I wrote a small
application to display temperature reading on a label widget. It displays
the temperature but does not get updated realtime.

I have copied the tcl tk program below. Please help me to diagnose the
problem with the below code.

Many thanks,

Nalaka

Code :
wm geometry . 360x150+200+100
pv linkw temp temp_val1
pv umon temp change
label .l1 -font {Helvetica 16}  -text " $temp"

#button .btnchange -text change -command {change} -font { -size 15}
grid .l1 -row 0  -column 0
#grid .btnchange -row 1 -column 0

#label .l1 -font {Helvetica 16} -width 10 -textvariable temp

proc change {} {
  global temp
.1l configure -text "$temp"
}

Experimental Physics and Industrial Control System

Experimental Physics and
Industrial Control System