Re: POE, log4perl and sqlite

On Oct 18, 2012, at 07:58, Antti Linno wrote:

> First of all, I have to apologise. Still no pastebin.

We have to apologize, too.  You're asking questions about code we cannot =
see.  This impairs our ability to provide satisfying answers.

> But a general tree would be something like that.
>=20
> Main POE module, imported submodule1, imported submodule2. All 3
> modules open the same logger conf and use the same sqlite file to
> append the log. Theoretically the log file could be locked, if all 3
> or even 2 modules try to write at the same time.

No.  As others have said, POE doesn't pre-empt.  Under ordinary =
circumstances, we expect all three modules to call Log::Log4perl =
sequentially rather than concurrently.  We don't expect Log::Log4perl =
suffer from lock contention.

It's very likely that something extraordinary is happening as a result =
of code we cannot see.  Others have already outlined the most likely =
reasons for the symptoms you described.  I hope you understand that's =
the best we can do without your cooperation.

> What would be the nice and tidy thing to do? Initialize logger in main
> POE module and pass it to submodules?

That's such a good question that Log::Log4perl already answers it:

"Why Log::Log4perl->get_logger and not Log::Log4perl->new? We don't want =
to create a new object every time. Usually in OO-Programming, you create =
an object once and use the reference to it to call its methods. However, =
this requires that you pass around the object to all functions and the =
last thing we want is pollute each and every function/method we're using =
with a handle to the Logger:

[example omitted]

"Instead, if a function/method wants a reference to the logger, it just =
calls the Logger's static get_logger($category) method to obtain a =
reference to the one and only possible logger object of a certain =
category. That's called a singleton if you're a Gamma fan."

That quote is from =
http://search.cpan.org/~mschilli/Log-Log4perl-1.38/lib/Log/Log4perl.pm#Ini=
tialize_via_a_configuration_file

--=20
Rocco Caputo <[email protected]>=