Hmmm. My bigger question is, are you still looking for assistance or do you have the book wrapped up?
On Aug 4, 7:42 am, mdipierro <mdipie...@cs.depaul.edu> wrote: > Almost done. 1-2 weeks. > > On Aug 4, 5:32 am, Pynthon <forumx...@gmail.com> wrote: > > > Nice, Massimo will there be a new book? > > > On 4 aug, 09:04, mdipierro <mdipie...@cs.depaul.edu> wrote: > > > > Changing now into utcnow would break backward compatibility. > > > > I do agree with you that othen people may want to use > > > > Field(....,default=datetime.utcnow()) > > > > instead of > > > > Field(....,default=request.now) > > > > I will add a comment about this in the book. > > > > Massimo > > > > On Aug 3, 3:22 am, Armin Ronacher <armin.ronac...@active-4.com> wrote: > > > > > Hi, > > > > > > True. but I would not call it a race condition. We timestamp > > > > > everything with the time when a request arrives, not when it is > > > > > processed, unless specified otherwise (datetime.now() instead of > > > > > request.now) > > > > > True. But that does not make it a better idea. Also, datetime.now() > > > > should be consistently replaced with datetime.utcnow() because using > > > > anythign else than UTC data internally is problematic for various > > > > reasons. See the discussion on that topic in various i18n/l10n > > > > libraries such as babel / pytz. > > > > > > True but I believe we never do that in web2py. It is also true that > > > > > nothing prevent the user from doing it but the same would be true with > > > > > other frameworks. > > > > > You're not doing it, a user might be doing that by accident or because > > > > he things it should work. This problem does not exist in other > > > > frameworks because besides web2py I don't know a single one that does > > > > this sort of execfile() + namespace thing or uses any other kind of > > > > throwaway modules. As soon as a single reference leaks from the > > > > execfile()'d namespace you're in big troubles and due to the open > > > > nature of Python this could happen very, very fast. > > > > > > Yes but because all relevant application code is executed within a > > > > > context and there are no references outside the context to stuff > > > > > inside the context, when a request is completed, the context is > > > > > deleted and everything should be garbage collected. > > > > > That depends on two things. First not having a reference leaked, > > > > which could happen with abstract base classes and other stuff that > > > > uses registries or steals non-weak references. Also and more > > > > importantly, the file descriptor limit is very low and the majority of > > > > Python implementations will only collect that on the GC run (always, > > > > no matter where references are). Say you're opening three files per > > > > request and you have more than 100 requests/sec you could lose all > > > > file descriptors that are available before the GC even thought about > > > > running. > > > > > Regards, > > > > Armin --~--~---------~--~----~------------~-------~--~----~ You received this message because you are subscribed to the Google Groups "web2py-users" group. To post to this group, send email to web2py@googlegroups.com To unsubscribe from this group, send email to web2py+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/web2py?hl=en -~----------~----~----~----~------~----~------~--~---
