Software Development Methodology!!!! 1. Use Cases 2. Requirements 3. Proposed Technical Design
Bonus points if you include Visio diagrams!!!! Top-posted for genuine experience!!!! On Mon, Oct 10, 2011 at 9:53 AM, Glyph <gl...@twistedmatrix.com> wrote: > Hi Andrew, > > Thanks for your work on this. > > On Oct 7, 2011, at 1:45 AM, Andrew Mahone wrote: > > I've been working on http://twistedmatrix.com/trac/ticket/4159 and > there has been a bit of discussion on IRC regarding appropriate > interfaces for various things. I think in the long run, the only > python state that setupChild should be allowed to modify should be > args, environment, and the win32 StartupInfo object. This leaves my > own personal use case for it impossible, but I'm working out how to > handle that - special childFDs objects. My proposal so far is that > there be a ProcessFileDescriptor object that inherits from > FileDescriptor. It would add a setup method, which Process would call > in the parent, and separate finishChild and finishParent methods that > would handle things like closing the other end of any pipe-like > objects, and would return a file descriptor - the child would place > this fd in childFDs, the parent would use it for communications with > the child, in the case of objects that wrap pipes or PTYs. I would > also extend the win32 implementation to include some limited support > for childFDs - they could be used to allow the child to inherit > specific file handles as its stdin, stdout, and stderr, instead of > using these exclusively for communications with the parent, so that > redirection to a pipe, to a file, and the building of pipelines could > be accomplished on win32 (I have a project that uses twisted for this > purpose, and I don't use windows, but I would like support to at least > be possible). > > > I've been sitting on this message for a couple of days trying to come up > with a good reply. Unfortunately this whole description is phrased in terms > of conflicting desires for the implementation, rather than a design strategy > or a set of goals or requirements for the API, so my attempted replies have > ended up playing whack-a-mole with the concerns one at a time, rather than > making an informed critique of the whole proposal. > > Could you try to re-phrase your design here in terms of why we want each of > these things, some use-cases, and then maybe spell out the methods and stuff > in terms of Python interfaces or classes (or perhaps links to your patch if > it already implements what you've described here)? > > Sorry that this probably isn't terribly useful feedback. I really > appreciate the time you've put in thus far, and I *think* I like where > you're going with this, I just haven't had time to turn everything > inside-out so that I can see it clearly :). > > I'm seeking comments on whether an extended childFDs interface is the > best way to manipulate the inherited files of the child process, and > whether, if so, fdmap ought to be visible in setupChild at all - in my > opinion, setupChild should be strictly for things like setting the > child PID in an environment variable or as a command line argument, > manipulating scheduler and other parameters external to twisted > itself, and other things of that nature, and the existing childFDs > mechanism should handle any manipulation of file redirection or > inheritance. If there are suggestions on what an extended childFD > object ought to look like, these are welcome as well - I think the > specified methods should handle trivial cases even on platforms > without fork, and should handle nearly anything that really is a file > descriptor on POSIX platforms, but maybe there is something I have > missed. > > > > > _______________________________________________ > Twisted-Python mailing list > Twisted-Python@twistedmatrix.com > http://twistedmatrix.com/cgi-bin/mailman/listinfo/twisted-python > > -- Christopher Armstrong http://radix.twistedmatrix.com/ http://planet-if.com/
_______________________________________________ Twisted-Python mailing list Twisted-Python@twistedmatrix.com http://twistedmatrix.com/cgi-bin/mailman/listinfo/twisted-python
