On Sat, May 9, 2015 at 11:00 PM, Sven Van Caekenberghe <sven@stfx.eu> wrote:
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.
Nice pick up. I checked and for each opened workspace their Process Monitor shows another process labelled "Workspace." Executing the example from the original post in a Workspace shows that Workspace waiting on the delay. So this aligns with one of the suggestions above. cheers -ben