httpd-users mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From Jonathan Trites <tritesni...@gmail.com>
Subject Re: [users@httpd] what the heck is a mutex and why cant I grab one?
Date Tue, 21 Sep 2004 00:57:05 GMT
A mutex is short for mutual exclusion. It is a concept that says that
a certain resource, such as a CD drive, can't be used by more than one
process/thread. In order to guarantee only one process will use the
resource, it is common for a program to first grab the mutex for the
resource, and then once it has it, it is free to use the resource.
Otherwise, the program will wait for it indefinitely or for a certain
amount of time, and once the other process currently using it is done,
it will release it and the waiting process can now grab it and use the
corresponding resource. If both processes were allowed to use it, they
would both be putting data onto the CD drive at the same time in the
above example. Obviously not a good thing. Hope that is clear enough.
This gives a better definition than mine:

http://dictionary.reference.com/search?q=mutex

I really can't speak to this with any authority, but I would guess
that apache is trying to get access to a port and is trying to be the
only one on that port to accept data which would be reasonable
considering it's a server. You don't usually want two programs
accepting the data from the same port. That is only a guess and I
don't know anything beyond my guess by looking at the error message.

It could be that it's a problem that has to do with the uninstall and
reinstall of the rpm packages, and my advice would probably be to try
and compile from source, although I know doing that is kind of
annoying. When I was playing around with linux, rpm installs going bad
was one of the biggest annoyances for me. Anyway, hope that clears up
a few things.


On Mon, 20 Sep 2004 11:56:12 -0700 (PDT), apchar boiir
<apchar_apache@yahoo.com> wrote:
> I'm running apache 2.0.48 on a mandrake linux box.
> Apache was acting flakey so I uninstalled all the
> apache2 RPMs and reinstalled them. Now it doesn't work
> at all! It wont start at boot up. In
> /var/log/http/error_log I see this:
> [Mon Sep 20 12:41:54 2004] [notice] suEXEC mechanism
> enabled (wrapper: /usr/sbin/apache2-suexec)
> [Mon Sep 20 12:41:55 2004] [notice] Digest: generating
> secret for digest authentication ...
> [Mon Sep 20 12:41:55 2004] [notice] Digest: done
> [Mon Sep 20 12:41:56 2004] [emerg] (13)Permission
> denied: couldn't grab the accept mutex
> [Mon Sep 20 12:41:56 2004] [emerg] (13)Permission
> denied: couldn't grab the accept mutex
> [Mon Sep 20 12:41:56 2004] [emerg] (13)Permission
> denied: couldn't grab the accept mutex
> [Mon Sep 20 12:41:56 2004] [notice]
> Apache-AdvancedExtranetServer/2.0.48 (Mandrake
> Linux/6mdk) mod_perl/1.99_11 Perl/v5.8.3
> mod_ssl/2.0.48 OpenSSL/0.9.7c PHP/4.3.4 configured --
> resuming normal operations
> [Mon Sep 20 12:41:56 2004] [alert] Child 1963 returned
> a Fatal error...
> Apache is exiting!
> [Mon Sep 20 12:41:56 2004] [emerg] (13)Permission
> denied: couldn't grab the accept mutex
> [Mon Sep 20 12:41:56 2004] [emerg] (22)Invalid
> argument: couldn't grab the accept mutex
> 
> What the heck is a mutex and why cant I grab one?
> 
> Note: I can manually start httpd with [I]httpd2 -k
> start[/I]  but the modules wont load, so I cant serve
> php files.
> 
> I dont see this in any FAQ.
> 
> What can I do?
> apchar.
> 
> __________________________________
> Do you Yahoo!?
> Yahoo! Mail - You care about security. So do we.
> http://promotions.yahoo.com/new_mail
> 
> ---------------------------------------------------------------------
> The official User-To-User support forum of the Apache HTTP Server Project.
> See <URL:http://httpd.apache.org/userslist.html> for more info.
> To unsubscribe, e-mail: users-unsubscribe@httpd.apache.org
>    "   from the digest: users-digest-unsubscribe@httpd.apache.org
> For additional commands, e-mail: users-help@httpd.apache.org
> 
>

---------------------------------------------------------------------
The official User-To-User support forum of the Apache HTTP Server Project.
See <URL:http://httpd.apache.org/userslist.html> for more info.
To unsubscribe, e-mail: users-unsubscribe@httpd.apache.org
   "   from the digest: users-digest-unsubscribe@httpd.apache.org
For additional commands, e-mail: users-help@httpd.apache.org


Mime
View raw message