From: Jeffrey Creem <jeff@thecreems.com>
Subject: Re: Reading and writing a big file in Ada (GNAT) on Windows XP
Date: Sat, 28 Apr 2007 14:28:56 -0400
Date: 2007-04-28T14:28:56-04:00 [thread overview]
Message-ID: <fcgcg4-fbs.ln1@newserver.thecreems.com> (raw)
In-Reply-To: <m2ejm4crhc.fsf@mac.com>
Simon Wright wrote:
> Fionn Mac Cumhaill <invisible@hiding.from.spam> writes:
>
>> The modifications consist of replacing a slice of text at the end of
>> a line with another bit of text. The biggest slice is 10 characters,
>> and the replacement slice is always smaller than the original
>> slice. An occasional line of text is about 6000 characters long, but
>> most are about 700 haracters. Get_Line reads them into a String
>> variable that is 10,000 characters long.
>
> Yesterday I found a performance (and stack!) related problem in GNAT's
> Ada.Strings.Fixed.Index. The string is mapped onto the stack before
> the search is done. But I wouldn't have thought this would result in a
> 5 hour run time. How do you decide which lines need conversion?
I agree, it does not seem that either that or the guesses I had related
to zeroing at the string (a common mistake) would result in the level of
slowdown being seen...However, now that you mention it, I see a few ugly
things like that related to Ada.Strings.Fixed. Did you submit a bug
report to FSF GCC?
As for the original poster, any chance you are doing dynamic memory
allocation and leaking and perhaps causing swapping?
next prev parent reply other threads:[~2007-04-28 18:28 UTC|newest]
Thread overview: 45+ messages / expand[flat|nested] mbox.gz Atom feed top
2007-04-28 5:03 Reading and writing a big file in Ada (GNAT) on Windows XP Fionn Mac Cumhaill
2007-04-28 5:20 ` Gautier
2007-04-29 21:17 ` Fionn Mac Cumhaill
2007-04-28 5:25 ` tmoran
2007-04-28 6:56 ` Martin Krischik
2007-04-28 17:12 ` tmoran
2007-04-28 12:41 ` Jeffrey Creem
2007-04-29 21:35 ` Fionn Mac Cumhaill
2007-04-28 13:22 ` (see below)
2007-04-28 17:56 ` Simon Wright
2007-04-28 18:28 ` Jeffrey Creem [this message]
2007-04-29 7:20 ` Simon Wright
2007-04-29 21:44 ` Fionn Mac Cumhaill
2007-04-29 21:42 ` Fionn Mac Cumhaill
2007-04-30 0:48 ` Jeffrey R. Carter
2007-04-30 2:30 ` Fionn Mac Cumhaill
2007-04-30 4:21 ` tmoran
2007-04-28 19:12 ` Jeffrey R. Carter
2007-04-29 21:46 ` Fionn Mac Cumhaill
2007-05-01 14:10 ` Fionn Mac Cumhaill
2007-05-06 21:55 ` Quarc
2007-05-02 7:46 ` george
2007-05-03 6:31 ` Fionn Mac Cumhaill
2007-05-03 20:00 ` Simon Wright
2007-05-04 4:35 ` Jeffrey R. Carter
2007-05-04 4:45 ` Fionn Mac Cumhaill
2007-05-04 6:53 ` Alternative Index implementation? (Was: Reading and writing a big file in Ada (GNAT) on Windows XP) Jacob Sparre Andersen
2007-05-04 7:41 ` Dmitry A. Kazakov
2007-05-04 9:16 ` Copying string slices before calling subroutines? (Was: Alternative Index implementation?) Jacob Sparre Andersen
2007-05-04 9:44 ` Copying string slices before calling subroutines? Jacob Sparre Andersen
2007-05-04 10:14 ` Dmitry A. Kazakov
2007-05-04 12:07 ` Jeffrey Creem
2007-05-04 12:46 ` Dmitry A. Kazakov
2007-05-04 22:27 ` Simon Wright
2007-05-05 7:33 ` Jacob Sparre Andersen
2007-05-05 7:47 ` Dmitry A. Kazakov
2007-05-05 7:41 ` Dmitry A. Kazakov
2007-05-03 20:27 ` Reading and writing a big file in Ada (GNAT) on Windows XP Adam Beneschan
2007-05-03 23:01 ` Randy Brukardt
2007-05-04 0:28 ` Markus E Leypold
2007-05-05 16:26 ` Adam Beneschan
2007-05-05 17:27 ` Markus E Leypold
2007-05-15 23:03 ` Randy Brukardt
2007-05-04 20:04 ` Adam Beneschan
2007-05-05 16:36 ` tmoran
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