From: eachus@spectre.mitre.org (Robert I. Eachus)
Subject: Re: Ada replacements for DOS I/O
Date: 3 Nov 94 09:24:26
Date: 1994-11-03T09:24:26+00:00 [thread overview]
Message-ID: <EACHUS.94Nov3092426@spectre.mitre.org> (raw)
In-Reply-To: dewar@cs.nyu.edu's message of 31 Oct 1994 08:21:41 -0500
In article <392r15$gl3@schonberg.cs.nyu.edu> dewar@cs.nyu.edu (Robert Dewar) writes:
> Of course simultaneous text_io from separate tasks to the same file (e.g.
> standard output) is pretty hard to define anyway (at what level does the
> output get interleaved - lines, text_io calls, characters, pixels?)
Characters, Robert, characters. ;-)
More seriously, chapter 14 is written to require, at worst, that
gets and puts of individual characters be treated as indivisible
actions. Any reasonable tasking aware version of TEXT_IO can and
should lock at a higher level, but it is almost impossible to treat
Text_IO calls as atomic. (For example, a read of a number can require
reading thousands of bytes from the external file.)
When I've written tasking aware versions of Text_IO (usually by
revising the vendor supplied I/O routines and calling the result
Nice_IO or Tasking_IO), the locking granularity was either a line of
text or a text_io call, whichever was smaller.
--
Robert I. Eachus
with Standard_Disclaimer;
use Standard_Disclaimer;
function Message (Text: in Clever_Ideas) return Better_Ideas is...
next prev parent reply other threads:[~1994-11-03 9:24 UTC|newest]
Thread overview: 19+ messages / expand[flat|nested] mbox.gz Atom feed top
1994-10-27 11:25 Ada replacements for DOS I/O Elgar the Idiot aka Chris Warwick
1994-10-27 23:04 ` Robert Dewar
1994-10-31 15:08 ` Mark Bayern
1994-11-03 11:23 ` Robert Dewar
1994-11-04 8:17 ` Samuel Tardieu
1994-11-06 21:03 ` Robert Dewar
1994-10-28 12:17 ` Ted Dennison
1994-10-31 13:21 ` Robert Dewar
1994-11-03 9:24 ` Robert I. Eachus [this message]
1994-11-05 5:37 ` Robert Dewar
1994-11-01 14:42 ` David Emery
1994-11-02 14:40 ` David Weller
1994-11-02 15:20 ` Robert I. Eachus
1994-11-03 13:01 ` Bevin R. Brett
-- strict thread matches above, loose matches on Subject: below --
1994-10-29 22:01 tmoran
1994-10-31 12:46 cwarwick
1994-10-31 19:31 tmoran
1994-11-03 3:15 tmoran
1994-11-03 23:05 ` Robert Dewar
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