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From: Uwe Klein <u...@klein-habertwedt.de>
Newsgroups: comp.lang.tcl
Subject: Re: How to interrupt a task which is running in a thread?
Date: Fri, 28 Sep 2012 09:46:53 +0200
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Andy wrote:
> 在 2012年9月28日星期五UTC+8下午2时11分37秒，Gerald W. Lester写道：
> 
>>The example you cited before, file copy, does not require threads -- in Tcl/Tk most things don't. Tcl is not Java -- make use of the event loop or co-routines not threads. Only use threads for things that either (a) block or (b) can/need to be done in parallel (and you have multiple cores/cpus). P.S. -- in the case of (b), it might be better to spawn off separate processes. On 9/27/12 9:34 PM, Andy wrote: > The task is still running even if I have released the thread. > > package require Thread > > set t1 [ thread::create { > proc test { } { > while {1} { > after 1000 > puts hello > } > } > thread::wait > }] > > thread::send -async $t1 [ list test ] > > puts [ thread::names ] > after 3000 > > thread::release $t1 > puts [ thread::names ] > vwait forever > -- +------------------------------------------------------------------------+ | Gerald W. Lester, President, KNG Consulting LLC | | Email: Gerald...@kng-consulting.net | +----------------------------------------------------
--------------------+
> 
> 
> Hi Gerald
> 
> But if I don't use thread, my GUI will be stuck. Could you give me an example?

simple example:

#!/usr/bin/wish

button  .start  -text Start -command {handlecmd X start}
button  .stop   -text Stop  -command {handlecmd X stop}
grid    .start  .stop

proc handlecmd {_id action} {
         upvar ::$_id id
         switch -- $action \
         start {
                 if {![catch {set id} cerr]} {
                         puts stderr "Task runs already"
                         return
                 }
                 set id [ exec ping localhost & ]
         } stop {
                 if {[catch {set id} cerr]} {
                         puts stderr "Task does not run"
                         return
                 }
                 exec kill $id
                 unset id
         }
}

uwe