On Sat, May 9, 2015 at 10:09 PM, Ben Coman <[email protected]> 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
