Re: [Lcd4linux-devel] My first mail, my first plugin, my fisrt SEGFAULT

[Michael R. <re...@eu...>]

I'm resending this mail because i got several "relaying denied" errors 
from my provider. Sorry if you get this twice...


Hi Javi,

>> MYSQL conex; mysql_init(&conex);

> :) That was the problem!. I was using the code that the oficial
> tutorial shows as an exaple so I supposed it to be correct.

Great! I love it when I can fix bugs with both eyes blind :-)

> Ok. I just was disappointed because I thoght there could be a problem
> in the mysql_init() out of my programing level . I'll continue
> developing the plugin, adding and improveing new features.

Fine! So you are the maintainer of the MySQL-plugin! There are several
things to manage:

- you should be subscribed to the lcd4linux-devel mailing list

- you will get a developer access for the SourceForge CVS. Do you
already have a account on SourceForge? If not, please get one, and tell
me your username.

>> But I see another problem here: These plugins can take some time to
>>  deliver a result (if, for example, the query is quite complicated,
>> or lots of rows are affected) This would distrub lcd4linux's quite
>> tight timings.
> 
> Because of its simplicity, MySQL is a very quick DB manager but I
> don't know if it can satisfy lcd4lnux's time requirements.

I'm afraid it will not. Especially if the monitored database is on
another server (which is possible, isn't it?)

>> Such plugins should work asynchronously. Which in turn is quite
>> complex to implement. The plugin should fork() on initialization,
>> the child would be responsible for fetching the data, the parent
>> takes the results via shared memory (and locked by a mutex) and
>> delivers them to the evaluator.
> 
> hummmmm, my programing level still can't reach these stuffs

Ok, lets go for it the following way: You cevelop and maintain the
plugin in a "normal" way, and I try to implement the async stuff with
the mail plugin, and finally we put things together.

bye, Michael

-- 
Michael Reinelt                                   Tel: +43 676 3079941
Geisslergasse 4                                   Fax: +43 316  692343
A-8045 Graz, Austria                          e-mail: re...@eu...