On Friday, February 05, 2010, at 01:01PM, "has" <hengist.p...@virgin.net> wrote: >Christopher Barker wrote: > >> Peter Hanson, on the wxPython list, seems to have identified a bug in the >> gestalt module, that may be a Carbon issue. It's a bit of an unusual case: >> it freezes up wxPython, when wx is called from other than the main thread. >> Robin Dunn suspects that it's a Carbon issue -- gestalt is calling Carbon, >> and doing so in the main thread, so you are then trying to call Carbon from >> more than one thread, which may be the cause of the problem. I've confirmed >> that if you call gestalt from the same thread as wxPython, there is no >> failure. > >Is wx/Mac not already built upon Carbon/Cocoa APIs? Cocoa's GUI APIs certainly >aren't thread-safe - all calls must go through the main thread - and I doubt >Carbon's GUI APIs are any different. So I'd hazard that Peter's just run afoul >of that fundamental limitation of OS X's GUI APIs, and it's purely dumb luck >that it didn't happen sooner. In which case, I think the only sensible >solution is to rework his application code to ensure all GUI calls are made on >the main thread, as I doubt the situation will improve any as wx moves to >Cocoa.
That's what I thought as well, Cocoa requires that GUI calls are made on the main thread. There are some calls that are allowed on a secondary thread, but most of them require that the main thread runs a runloop as well. <http://developer.apple.com/mac/library/documentation/cocoa/conceptual/Multithreading/AboutThreads/AboutThreads.html> seems to suggest that you can call Carbon APIs from a thread other than the main thread (that's the only way "Threads and Your User Interface" makes sense). This means that creating the GUI in a secondairy thread may be safe for wx/Carbon, but will definitly break in wx/Cocoa. > > >> As Carbon is deprecated anyway, I guess it's time for gestalt ( or >> platform.mac_ver ) to be re-written > > >Python's Carbon modules are deprecated in 2.x and gone in 3.x, so its >Carbon.gestalt module is a dead end for Python users. Mac OS X's gestalt APIs >are not deprecated, however, so I don't see why platform.mac_ver would need >changed. I will remove the offending gestalt call for 2.7 and 3.2 because the result isn't used on any supported platform. I might backport that change to 2.6 and 3.1. The gestalt bindings won't go away. Ronald _______________________________________________ Pythonmac-SIG maillist - Pythonmac-SIG@python.org http://mail.python.org/mailman/listinfo/pythonmac-sig
