> On 09 May 2015, at 16:41, Ben Coman <btc@openinworld.com> wrote:
>
>
>
> On Sat, May 9, 2015 at 10:09 PM, Ben Coman <btc@openinworld.com> wrote:
> From my limited experience bug hunting, calling #changed: from a thread other than the UI thread is a source of evil.�� There are too many assumptions throughout the system that the UI is single threaded.�� Can anyone advise me that is not a proper belief?
>
> Then that implies that a Transcript implementation where #nextPut: direct calls #changed:
> is not appropriate for use with multi-threaded applications.�� In Pharo, #changed: is only called from #stepGlobal, which is called from doOneCycle:.�� (This came about as a last minute bug fix before Pharo 3 release and maybe could use some cleanup.
>
> Separating the UI from Transcript into its own viewer might be a good idea, but actually it would not solve Stef's case since his code would still be running in the UI thread -- unless the viewer ran in another thread, which would have its own complexities.
>
> I think the point about efficiency is significant. The following example...
>�� �� �� Time millisecondsToRun: [ 1000 timesRepeat:�� [ Transcript show: 'x' ] ]
> on Squeak 4.5 --> 12749ms
> on Pharo 50029 --> 2ms
>
> As a point of comparison, on VW 8.0 --> 43817ms
> and so you might guess, VW 8.0 outputs each 'x' immediately.
> cheers -ben

I am not sure, but in VW it looks like each Workspace (Window) is (executing its Doit) in a separate thread.��