Jeremy Hylton wrote:

....

The -with-cycle-gc flag is an option to configure when you build Python. It can't be turned on or off at runtime.

Doh! Sorry. Andrew's text does say that but I didn't read carefully and testing it with my stuff hasn't floated to the top yet (because when I looked into it, I realized I'd have to recompile...double doh!) Compiling is really slow on my "transitional" computer. I'm a little disappointed that it will be so difficult for people to test with GC on, but I'm not going to claim that there is some easy way to make it a runtime option because I haven't looked at it at all. There probably isn't. -- Paul Prescod - Not encumbered by corporate consensus The calculus and the rich body of mathematical analysis to which it gave rise made modern science possible, but it was the algorithm that made the modern world possible. - The Advent of the Algorithm (pending), by David Berlinski

On Wed, Jun 28, 2000 at 11:09:38AM -0700, Paul Prescod wrote:

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I'm a little disappointed that it will be so difficult for people to test with GC on, but I'm not going to claim that there is some easy way to make it a runtime option because I haven't looked at it at all. There probably isn't.

There isn't. With an interpreter compiled --with-cycle-gc you can turn off the collection with gc.set_threshold(0) but that's not the same thing.

Neil

I wonder if we should turn this option *on* during beta testing? That way we gather a lot more experience with its use! Maybe nobody complains and we can leave it on in the final release... --Guido van Rossum (home page: http://www.python.org/~guido/)

Guido van Rossum wrote:

I wonder if we should turn this option *on* during beta testing?

Why not, as long as --without-gc does not suffer from bugs hidden by --with-gc.

That way we gather a lot more experience with its use! Maybe nobody complains and we can leave it on in the final release...

This is risky. We don't have enough experience with this implementation. All we know is that things get slower and consume more memory. Without a clear picture of the impact of this GC implementation, it's probably a bad idea to enable (i.e. impose) it by default. The "optional experimental feature" label is good and IMO it complies with anybody's expectations. Interested people will jump in and will eventually contribute with improvements, those who don't care won't and will live happily without it (at least until the day the feature and its implementation reach their expected maturity). -- Vladimir MARANGOZOV | Vladimir.Marangozov@inrialpes.fr http://sirac.inrialpes.fr/~marangoz | tel:(+33-4)76615277 fax:76615252

Won't we have a clear picture by the end of the beta period?

Not clear. Unfortunately, few people who run important apps will download a beta and try it. But they *will* download a new release labeled "final" and install it without making sure it works for their app. This has been my experience throughout Python's life. I've become pretty conservative about staying backwards compatible as a result...

...

The "optional experimental feature" label is good and IMO it complies with anybody's expectations. Interested people will jump in and will eventually contribute with improvements, those who don't care won't and will live happily without it (at least until the day the feature and its implementation reach their expected maturity).

A million Window users will live unhappily without it because they don't know how to recompile to get it!

This can be solved the way we solve everything for Windows users: give them two distributions to choose from -- or maybe one distribution with a checkbox to choose which version to use. --Guido van Rossum (home page: http://www.python.org/~guido/)

On 28 June 2000, Jeremy Hylton said:

PP> import cyclicgc

PP> should turn on the -with-cycle-gc flag.

The -with-cycle-gc flag is an option to configure when you build Python. It can't be turned on or off at runtime.

No, no, *obviously* Paul meant that "import cyclicgc" should configure and compile a new Python interpreter with "--with-cycle-gc" and 'exec()' it for you. What else would it mean? ;-) Greg (PS. if this were Perl, you could say use cyclegc; to turn it on, and then elsewhere in your code no cyclegc; to turn it off. Maybe Python needs an "unimport" command?) (Kidding!)