Re: Understanding Apache Mutex directive.

[Mike Rumph <mike.rumph@xxxxxxxxxx>]

Hello dE,

I can only give you my own interpretation of this document.

First of all the Mutex directive in Apache httpd 2.4.x replaces several different directives from Apache httpd 2.2.x.
The SVN commit for this is 883540.
- http://svn.apache.org/viewvc?view=revision&revision=883540

The phrase "the first argument" in both cases probably means the first argument after the mechanism.
The doc should be worded more clearly.  (So this should probably changed to "the second argument".)

The mechanism is what kind of mutex technology is used.
Apache httpd uses several different mutexes for different purposes.
The mutex-name specifies which of these mutexes the Mutex directive applies to.
It is a little confusing that either one of these arguments can have the value "default".

So the phrase "The following mutex mechanisms are available:" applies to the mechanism  (argument 1).
And the phrase "The following table documents" applies to the mutex-name (argument 2).

I hope this helps.

Thanks,

Mike Rumph

On 9/2/2014 10:10 PM, dE wrote:

Hi.

I was reading this --

http://httpd.apache.org/docs/trunk/mod/core.html#mutex

Quoting what's written here --

Specify default as the first argument to change the settings for all mutexes

As we know mutex is a mechanism; it appears Apache has settings for each mutex it implements.

specify a mutex name (see table below) as the first argument to override defaults only for that mutex.

So the table starting with 'The following table documents....' lists all the mechanisms. But before the table there exists a list with the heading 'The following mutex mechanisms are available:'.

So I don't understand which one of these is the mutex mechanism.

Also the statement --

specify a mutex name (see table below) as the first argument to override defaults only for that mutex.

Contradicts the examples --

Mutex sysvsem default
Mutex fcntl:/var/httpd/locks mpm-accept

Where the entries in the table are not the first argument, instead the list starting with 'The following mutex mechanisms are available:' is.

Thanks for any clarification.