Google Chrome

[Hal Duston]

On Fri, Sep 05, 2008 at 10:41:07AM -0500, Hal Duston wrote:
> On Fri, Sep 05, 2008 at 09:27:13AM -0500, Monty J. Harder wrote:
> > 
> > Yes, they exec to spawn these separate processes.  But those processes can't
> > change the arguments under which they were invoked without themselves
> > exec-ing all over again.  So when you click on a "Heh.", you'd have to
> > change one process from
> > monster 3952 26665 0 10:08 ? /usr/lib/firefox-4.0/firefox-bin -UILocale
> > en-US instapundit.com
> > to
> > monster 3952 26665 0 10:08 ? /usr/lib/firefox-4.0/firefox-bin -UILocale
> > en-US  johndoe.blogspot.com/2008/09/snarky-article-title-here.html
> > 
> > The only way I know to do that is to exec firefox-bin, invoking the new URL
> > as an argument.   What I don't know is how much overhead that takes.  I
> > suppose a stripped-down binary, that inherits a pre-built environment
> > populated by another binary reading configs, etc., might not be doable.
> > 
> > But that's not the way that any existing browser I know of is written.
> > You're talking about a complete re-factoring of how browsers work.  That's
> > not to say that it's a bad idea, just that it's a non-trivial effort, which
> > might make things much slower
> 
> A process can change the arguments at any time w/o doing an exec.  I have
> actually read the code that is needed to do this under Linux.  It is less
> than 15 lines.  All it does is rebuild the environment which is where the
> exec'ed command line arguments are kept.  Once they are rebuilt ps,  top,
> and everything else just pick them up from /proc/<pid>/cmdline.
> 

A quick example I threw together in just a few minutes:

$ wc -l xxq.c
71 xxq.c
$ ./xxq "This process changed its arguments" & ps  -f
[1] 1524
UID        PID  PPID  C STIME TTY          TIME CMD
hald      1524 32251  0 11:12 pts/7    00:00:00 This process changed its arguments
$ ./xxq "This process changed its parameters" & ps  -f
[2] 1532
UID        PID  PPID  C STIME TTY          TIME CMD
hald      1532 32251  0 11:13 pts/7    00:00:00 This process changed its parameters

> Thanks,
> --
> Hal