new directive (was Re: [patch] adding mpm info to httpd -V)

[Geoffrey Young <ge...@modperlcookbook.org>]

>> <IfThreaded>
>>     MaxThreadsPerChild   5
>> </IfThreaded>
> 
> 
> This rubs me the wrong way FWIW.  

oops, sorry :)

> I think it is best to have all
> directives for a specific MPM together in one container, and have that
> container specific to the MPM.  

well, in some cases I'd certainly agree.  however, I think that some "if I
have a threaded MPM" container would be genuinely useful.  consider the
perl-framework, where the default httpd.conf that is generated has the exact
same directives

<IfModule worker.c>
    StartServers         1
    MaxClients           1
    MinSpareThreads      1
    MaxSpareThreads      1
    ThreadsPerChild      1
    MaxRequestsPerChild  0
</IfModule>

for both worker and perchild (and we'd need the same for leader someday I
suppose).

granted, this kind of duplication might make sense in some circumstances.
however, specifically for non-core directives it might be nice to have such
a feature.  for instance, I can see some value in

<IfThreaded>
  # if using a threaded mpm load some ultra-slow but threadsafe
  # version of some ultra-fast but non-threadsafe module
</IfThreaded>

if this kind of thing (someday) applies to, say, php folks, then asking them
to duplicate this for each and every possible threaded MPM seems to be
asking a bit much.

but maybe this is all just academic anyway.  thanks for listening
nonetheless :)

> If somebody really wants to do this they
> could use IfDefine;  though it would be easier if the core pre-defined
> some symbol for use in IfDefine, it is doable as-is.

sure.  the only reason I didn't go that way was that the docs seem to say
that <IfDefine> only applies to -D command-line parameters - I wasn't
familiar enough with the directives to see if there were other, internal -D
flags that were also used.

--Geoff

Re: new directive (was Re: [patch] adding mpm info to httpd -V)

[Geoffrey Young <ge...@modperlcookbook.org>]

William A. Rowe, Jr. wrote:
> At 02:10 PM 12/3/2003, Geoffrey Young wrote:
> 
> 
>>>><IfThreaded>
>>>>    MaxThreadsPerChild   5
>>>></IfThreaded>
>>>
>>>
>>>This rubs me the wrong way FWIW.  
>>
>>oops, sorry :)
> 
> 
> I don't care for that container either... but even horrible new ideas 
> are always good when then generate more ideas :)

:)

> 
> 
>>>If somebody really wants to do this they
>>>could use IfDefine;  though it would be easier if the core pre-defined
>>>some symbol for use in IfDefine, it is doable as-is.
>>
>>sure.  the only reason I didn't go that way was that the docs seem to say
>>that <IfDefine> only applies to -D command-line parameters - I wasn't
>>familiar enough with the directives to see if there were other, internal -D
>>flags that were also used.
> 
> 
> Actually, such defines might need to be a little more dynamic, but either
> <IfDefine AP_MPM_THREADED> would be good, or if we absolutely
> needed too, we could add <IfFeature FOO> where features could be
> registered, by the core or by a loaded module.

actually, the other idea I had (going for 0-2 on the horrible new idea theme
:) was <IfMPM AP_MPMQ_IS_THREADED> (or somesuch) as a direct interface to
ap_mpm_query, but I thought that outside of threaded/forked there wasn't
much other useful config-time information there.

but either/any form would probably be valuable to somebody somewhere along
the line.

> 
> Individual <IfFoo> blocks would pollute the command table significantly,
> slowing down config parsing by a corresponding amount.

ah, good point.

--Geoff

Re: new directive

[Geoffrey Young <ge...@modperlcookbook.org>]

> Actually, such defines might need to be a little more dynamic, but either
> <IfDefine AP_MPM_THREADED> would be good, or if we absolutely
> needed too, we could add <IfFeature FOO> where features could be
> registered, by the core or by a loaded module.

to that end, here's a preliminary and rough patch for

<IfServerIs !threaded>

(substitute 'IfServerIs' for whatever you please - I'm not so good with names).

I couldn't think of anything else to implement other than threadedness right
now, but I guess we're discussing the concept at the moment so that's ok.  I
did almost start on

<IfServerIs >= 2.1>

but I thought that the new container semantics probably wouldn't go over
well (and I wasn't entirely convinced that was a worthy thing to test at
config time).

--Geoff

Re: new directive (was Re: [patch] adding mpm info to httpd -V)

["William A. Rowe, Jr." <wr...@apache.org>]

At 02:10 PM 12/3/2003, Geoffrey Young wrote:

>>> <IfThreaded>
>>>     MaxThreadsPerChild   5
>>> </IfThreaded>
>> 
>> 
>> This rubs me the wrong way FWIW.  
>
>oops, sorry :)

I don't care for that container either... but even horrible new ideas 
are always good when then generate more ideas :)

>> If somebody really wants to do this they
>> could use IfDefine;  though it would be easier if the core pre-defined
>> some symbol for use in IfDefine, it is doable as-is.
>
>sure.  the only reason I didn't go that way was that the docs seem to say
>that <IfDefine> only applies to -D command-line parameters - I wasn't
>familiar enough with the directives to see if there were other, internal -D
>flags that were also used.

Actually, such defines might need to be a little more dynamic, but either
<IfDefine AP_MPM_THREADED> would be good, or if we absolutely
needed too, we could add <IfFeature FOO> where features could be
registered, by the core or by a loaded module.

Individual <IfFoo> blocks would pollute the command table significantly,
slowing down config parsing by a corresponding amount.

Bill