John,
Lol. You're full of little red ants.
--brian
On Fri, 10 Oct 2003, John A. Boyd Jr. wrote:
> Point taken, Brian, IF read & write close are to do exactly the same
> thing. What it they are to be different?
>
> This has become a philosophical debate, and unfortunately, as I've noted
> often lately, I don't have access here to any STREAMS docs (mine have
> been in storage for more than a year now). So, I have to trust the
> rest of you on this kind of issue. But, I don't take MG as
> authoritative, again, because it predates some important capabilities
> and some open/close-related semantics changes as a result. I don't
> need my docs for that.
>
> Dave G. can speak to this likely better than I, Dave L., but open and
> close semantics are different; that was the subject of the recent
> discussion "Opinions, please" that he started. When the docs say
> that the driver open is called for each stream open, but close is
> called only for the last close, it may be referring to that aspect.
> But that doesn't preclude the last close from being two routines,
> each to be called, for the read and write queues resp. I.e., there
> is possibly an ambiguity here. I'm not trying to resolve it, but
> as in that case, I am doing what I can to identify it.
>
> You may have a good point, though, Dave L., that if there are two
> different open routines, maybe both should be called. Another
> possible ambiguity. I just don't want us all rushing to judgement,
> and leaving LiS less flexible than it should be as a result.
>
> My opinion is that when reading documentation meant not for
> implementors but for users, the implementor _must_ find and follow
> the broadest possible reading, not the most narrow. The authors
> weren't likely writing to be as precisely followed as an implementor
> needs, but to be as easily understood as a user needs.
>
> So, Brian, with all due respect to you, I think you have good
> points, but I also think your reading is too narrow, and thus has
> the effect of limiting flexibility. I try to avoid that when I
> can; you certainly don't have to avoid it, though, if you don't
> want to. We obviously make our implementation choices with
> different criteria in mind.
>
> -John
>
> Brian F. G. Bidulock wrote:
> > John,
> >
> > One more point on this:
> >
> > If the read close routine wants the write close routine called, it can
> > call it itself before returning:
> >
> > int xxx_close(queue_t *q, int oflag, cred_t *credp)
> > {
> > ...
> > ...
> > return WR(q)->qi_qinfo->qi_qclose(WR(q), oflag, credp);
> > /* or even more directly xxx_wclose(WR(q), oflag, credp) */
> > }
> >
> > So it really makes no sense for qdetach to be calling it in any event.
> >
> > --brian
> >
> > On Fri, 10 Oct 2003, Brian F. G. Bidulock wrote:
> >
> >
> >>John,
> >>
> >>On Fri, 10 Oct 2003, John A. Boyd Jr. wrote:
> >>
> >>
> >>>Dave G. - how about checking to see if they're the same, if both are
> >>>set, and if they are, call only one? But otherwise, call whatever is
> >>>set, which may be both?
> >>>
> >>>I agree with you otherwise, though; I'd prefer to leave it as is.
> >>
> >>Why? When it goes against documented STREAMS behavior?
> >>
> >>On the other hand, what about qi_qopen()? Why are you not calling both
> >>qopens? One with the read queue pointer and the other with ther write?
> >>
> >>Because its not done that way, of course. And what is true for qopen()
> >>is true for qclose() in this case.
> >>
> >>--brian
> >>
> >>
> >>
> >>>-John
> >>>
> >>>David Lehmann wrote:
> >>>
> >>>>David Grothe wrote:
> >>>>
> >>>>
> >>>>>David:
> >>>>>
> >>>>>I think I see what is going on. Consider the following lines from the
> >>>>>trace:
> >>>>>...
> >>>>>Queues come in pairs. This loop is examining each queue of the pair
> >>>>>and calling the close routine for whichever queue has a pointer to a
> >>>>>close routine. Apparently your qinfo structure for your module has a
> >>>>>pointer to the close routine for both the read and write queues. It
> >>>>>is conventional to only provide open/close routine pointers for the
> >>>>>read queue.
> >>>>>
> >>>>>I think if you change your qinit structure the problem will go away.
> >>>>
> >>>>
> >>>>Maybe so, but this is the same code that Solaris uses.
> >>>>My understanding is that close should be called once and only once
> >>>>for the queue pair. Maybe you should take John's suggestion and
> >>>>set do_close to zero after executing the close routine once.
> >>>>
> >>>
> >>>
> >>>_______________________________________________
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> >>
> >>--
> >>Brian F. G. Bidulock � The reasonable man adapts himself to the �
> >>[EMAIL PROTECTED] � world; the unreasonable one persists in �
> >>http://www.openss7.org/ � trying to adapt the world to himself. �
> >> � Therefore all progress depends on the �
> >> � unreasonable man. -- George Bernard Shaw �
> >>
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> >
>
>
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Brian F. G. Bidulock � The reasonable man adapts himself to the �
[EMAIL PROTECTED] � world; the unreasonable one persists in �
http://www.openss7.org/ � trying to adapt the world to himself. �
� Therefore all progress depends on the �
� unreasonable man. -- George Bernard Shaw �
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