[Pyobjc-dev] Startup time woes

[Just v. R. <ju...@le...>]

[this started as a private conversation, I guess it makes more sense on
the list now]

Bill Bumgarner wrote:

> Yes -- I'd like to know why it is so bloody slow, as well.
>
> I'm going to have to run it through the profiler sometime soon and see 
> what the deal is.
> 
> Part of the problem is certainly the bridging of *all* classes.  
> I.e. 'from AppKit import *' has to do a lot of work to make all of
> the classes available in the Python module, but I don't think that
> explains *all* of the slowdown.

Hm, I was also thinking it would have to be something different. I added
some print statements to a simple app (the pyDotView example that was
posted recently):

    (first run)
    after importing objc: 0.330672979355
    after importing Foundation: 0.997979998589
    after importing AppKit: 3.49985897541
    after importing MyAppDelegate: 3.72730898857
    (starting the event loop)
    initializing DotView: 11.8096979856
    
    (second run)
    after importing objc: 0.102402925491
    after importing Foundation: 0.417948961258
    after importing AppKit: 1.14622688293
    after importing MyAppDelegate: 1.30699288845
    (starting the event loop)
    initializing DotView: 8.59571492672

Times in seconds from the top of __main__. The "initializing" line is
from the DotView.initWithFrame_() method. Much time is spent between
starting the event loop and setting up the window. Weird.

This was with 2.2, however, with 2.3 I get a different number at the
end:

    (first run)
    after importing objc: 0.306917071342
    after importing Foundation: 0.843237996101
    after importing AppKit: 1.79104101658
    after importing MyAppDelegate: 1.98914909363
    (starting the event loop)
    initializing DotView: 3.40978002548
    
    (second run)
    after importing objc: 0.118615984917
    after importing Foundation: 0.377791047096
    after importing AppKit: 1.09300804138
    after importing MyAppDelegate: 1.22211098671
    (starting the event loop)
    initializing DotView: 2.63563001156

Still very slow for a trivial app, but quite a bit better. But why? 

Just