Re: cost of popen()

[Hideki IWAMOTO]

On Sat, 18 Jun 2005 08:52:18 +0900, Shigio Yamaguchi wrote...
> Yes, it does.
> Though plug-in parser in command layer is worthy in the flexibility,
> I have not heard someone make it. If it is not necessary, should we
> take rather the performance than the needless flexibility?

Exuberant Ctags and Emacs ctags can receive two or more files at a command line.
The performance can be improved keeping compatibility by processing two or more 
files by one parser.


This is comparison on AthlonXP 2200+ running FodoraCore3.

[linux-2.0.40]$ time  global -P | xargs -l  gtags-parser -dt >/dev/null
1.237user 1.156system 2.396elapsed 99.84%
[linux-2.0.40]$ time  global -P | xargs -l   gtags-parser -dtr >/dev/null
3.019user 4.518system 7.548elapsed 99.84%
[linux-2.0.40]$ time  global -P | xargs -l  gtags-parser -dts >/dev/null
3.276user 4.518system 7.810elapsed 99.78%
[linux-2.0.40]$ time  global -P | xargs -l  ctags -x>/dev/null
8.364user 9.639system 18.039elapsed 99.79%
[linux-2.0.40]$ time  global -P | xargs -l  gctags -x -D -t -w >/dev/null
2.354user 2.205system 4.565elapsed 99.84%

[linux-2.0.40]$ time  global -P | xargs   gtags-parser -dt >/dev/null
0.993user 0.140system 1.223elapsed 92.61%
[linux-2.0.40]$ time  global -P | xargs   gtags-parser -dtr >/dev/null
2.401user 0.208system 2.613elapsed 99.84%
[linux-2.0.40]$ time  global -P | xargs   gtags-parser -dts >/dev/null
2.628user 0.201system 2.834elapsed 99.81%
[linux-2.0.40]$ time  global -P | xargs   ctags -x>/dev/null
3.329user 0.659system 3.995elapsed 99.84%
[linux-2.0.40]$ time  global -P | xargs   gctags -x -D -t -w >/dev/null
1.850user 0.144system 1.998elapsed 99.80%

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Hideki IWAMOTO  address@hidden