Re: [boost] [flyweight] Review period extended to February 3

From: vicente.botet (vicente.botet_at_[hidden])
Date: 2008-02-01 12:46:30

"Joaquín Mª López Muñoz" wrotes

> "vicente.botet" ha escrito:
>
> > Hi Joaquin,
> >
> > What is the magic number 16384 in the intermodule_holder intantiator
> > struct intermodule_holder_class contains the following initialization
> >     instantiator():
> >       mutex(interprocess::open_or_create,compute_mutex_name()),
> >       seg(interprocess::open_or_create,compute_segment_name(),16384),
>
> intermodule_holder<T> creates a shared memory segment which is 
> (intendedly)
> unique to the combination (process,T), and it is used to share information 
> on the
> static data initialization process among the different dynamic modules in 
> the
> program.
>
> 16 KB is just a conventional size requested for the memory segment. 
> Actually,
> this segment only contains a pointer, but it's necessary that the segment 
> be larger
> than merely sizeof(void*) to accommodate object names and other
> Boost.Interprocess internal information. Maybe 16KB is a little too much 
> and
> we could do with 2 or 4 KB, but I didn't think it was worth being 
> avaricious here.

OK, I understand.

[snip]

> > Are the compute_mutex_name and compute_segment_name friendly for 
> > debuging?
> > I think that we will need here some introspection in order obtain these
> > values,or better yet to be able to configure them.
>
> The mutex_name (segment_name is similar) has the form
>
>   boost_flyweight_intermodule_holder_mutex_A_C0_C1_C2_C3
>
> where A is the current process ID and C0,...,C3 are numbers obtained from 
> hashing
> typeid(T).name(), T being the type in intermodule_holder<T>. The intention 
> is that
> this name is unique to the combination (process,T). I don't think it 
> should be
> configurable, since it's an internal detail and also because the 
> particular
> name chosen is crucial to ensuring that the segment is unique to 
> (process,T)
> (we're using a process-wide segment for intraprocess purposes.)

Sorry, I was yet thinking that the factory was allocated in this space.
We don't need never to access to these objects by name.

Forget please.

---------------------------
Vicente Juan Botet Escriba