From: Eli Zaretskii <eliz@gnu.org>
To: Paul Eggert <eggert@cs.ucla.edu>
Cc: jim@meyering.net, emacs-devel@gnu.org
Subject: Re: oops? read/write vs type of length parameter
Date: Wed, 13 Apr 2011 20:22:11 +0300 [thread overview]
Message-ID: <83bp0aqd6k.fsf@gnu.org> (raw)
In-Reply-To: <4DA5C9F6.3070209@cs.ucla.edu>
> Date: Wed, 13 Apr 2011 09:06:14 -0700
> From: Paul Eggert <eggert@cs.ucla.edu>
> CC: jim@meyering.net, emacs-devel@gnu.org
>
> On 04/13/2011 02:46 AM, Eli Zaretskii wrote:
> > I was asking whether testing errno for EWOULDBLOCK
> > and EAGAIN, and the code that deals with when that happens, are good
> > enough for all the possible reasons that emacs_write and
> > emacs_gnutls_write could return a partial count of bytes.
>
> The revised send_process code tests for EWOULDBLOCK and EAGAIN under
> the same conditions that it does now.
That's true, but it's not my point. The original code continued
looping and trying to write the rest of the stuff if emacs_write
returned a positive value that is smaller than what is was asked to
write. The new code bails out of the loop in that case, assuming that
it's due to an error.
> > sysdep.c is not about system things, it's about Emacs code that
> > requires platform-dependent techniques. Most of that indeed deals
> > with system types, but you will find quite a few Emacs specific
> > internals
>
> Yes, and I had already mentioned that the abstraction boundaries were
> sometimes being violated there. But let's not make matters worse.
> sysdep.c is supposed to be for interfaces to system-dependent kernel
> and library code, not for access to Emacs Lisp internals.
I was trying to point out that you are mistaken in your interpretation
of what sysdep.c is. But even I accept your POV, access to OS-level
features does not mean we cannot use Emacs-specific data types there
or forget about Emacs design. sysdep.c is not a library, it's part of
an application.
> >> For example, it would be a fairly small change to make Emacs buildable on
> >> a machine with 32-bit pointers and 64-bit EMACS_INT.
> >
> > Somehow, I doubt it is a small change. But if it is, by all means
> > let's do it now! What are we waiting for?
>
> I suspect you are joking, but if not, I'd be happy to implement it.
I'm not joking. How could I?
> It shouldn't take that long, and it'd be nice to remove that silly 512
> MiB limit. Would you object to such a change?
Of course not! Why should I object to a great feature like that?
> in the meantime, we have a proposed change that
> fixes bugs and doesn't introduce bugs. Since there are no downsides
> to this fix now, and no improvements to it have been suggested, we can
> install it now, and worry about future improvements later.
I'll let Stefan and Chong decide on that. I still think that using
ssize_t as the last argument to emacs_write is better.
> > Either you care about future changes or you don't.
>
> Both. I care about plausible future changes; and I also realize that
> we don't have time to program for all possibilities and need to fix
> what's before us, which the proposed patch does.
IOW, you care for what supports your arguments and don't care about
the rest.
next prev parent reply other threads:[~2011-04-13 17:22 UTC|newest]
Thread overview: 49+ messages / expand[flat|nested] mbox.gz Atom feed top
2011-04-11 8:55 oops? read/write vs type of length parameter Jim Meyering
2011-04-11 9:44 ` Eli Zaretskii
2011-04-11 11:08 ` Jim Meyering
2011-04-11 11:28 ` David Kastrup
2011-04-11 11:52 ` Eli Zaretskii
2011-04-11 12:27 ` Jim Meyering
2011-04-11 12:31 ` David Kastrup
2011-04-11 21:54 ` Jim Meyering
2011-04-12 4:44 ` Eli Zaretskii
2011-04-12 13:24 ` Ted Zlatanov
2011-04-12 13:29 ` Eli Zaretskii
2011-04-12 14:47 ` Ted Zlatanov
2011-04-12 17:00 ` Large file support (was: oops? read/write vs type of length parameter) Eli Zaretskii
2011-04-14 20:57 ` oops? read/write vs type of length parameter Michael Welsh Duggan
2011-04-11 14:02 ` Eli Zaretskii
2011-04-11 11:40 ` Stephen J. Turnbull
2011-04-11 13:58 ` Eli Zaretskii
2011-04-12 1:16 ` Paul Eggert
2011-04-12 3:01 ` Eli Zaretskii
2011-04-12 5:06 ` Paul Eggert
2011-04-12 5:46 ` Eli Zaretskii
2011-04-12 8:19 ` Paul Eggert
2011-04-12 9:41 ` Eli Zaretskii
2011-04-12 15:53 ` Paul Eggert
2011-04-12 16:56 ` Eli Zaretskii
2011-04-12 23:55 ` Juanma Barranquero
2011-04-13 5:14 ` Paul Eggert
2011-04-13 6:31 ` Jim Meyering
2011-04-13 6:37 ` Eli Zaretskii
2011-04-13 8:15 ` Paul Eggert
2011-04-13 9:46 ` Eli Zaretskii
2011-04-13 16:06 ` Paul Eggert
2011-04-13 17:22 ` Eli Zaretskii [this message]
2011-04-13 19:31 ` Paul Eggert
2011-04-13 19:59 ` PJ Weisberg
2011-04-14 4:49 ` Eli Zaretskii
2011-04-13 20:02 ` Paul Eggert
2011-04-13 6:49 ` Eli Zaretskii
2011-04-13 14:35 ` Ted Zlatanov
2011-04-15 13:13 ` Ted Zlatanov
2011-04-15 16:34 ` Paul Eggert
2011-04-15 18:20 ` Ted Zlatanov
2011-04-15 1:29 ` Stefan Monnier
2011-04-15 8:55 ` Paul Eggert
2011-04-15 9:41 ` Eli Zaretskii
2011-04-15 10:24 ` Paul Eggert
2011-04-12 12:32 ` Davis Herring
2011-04-12 13:38 ` Eli Zaretskii
2011-04-12 15:43 ` Paul Eggert
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