Re: [Boost-users] [bind] & [function] How do I store member functions with generalised arguments for later invocation?

Subject: Re: [Boost-users] [bind] & [function] How do I store member functions with generalised arguments for later invocation?
From: Steve Lorimer (steve.lorimer_at_[hidden])
Date: 2010-06-02 17:35:51

Thanks Nat, I didn't know about this yet (noob!)

>From a quick perusal (almost bed time :) !) I can't see how I would achieve
my aim, which is:

1. create the "event" (signal) which is associated with a member function
"callback" (slot). Associate a thread with the event
(can I create a signal connected to a slot which is a member function?)

2. in any other thread, call "post" (sig(data)) where data is a shared_ptr

3. the callback (slot) is called, running in the context of the *other*
thread (the one originally associated with the "event" / (slot).

I'm trying to encapsulate a generic inter-thread messaging system where
objects are passed around between threads, and associated with a member
function which is designed to process said objects.

This design is essentially a messaging system between threads - for a simple
example - we have a producer/consumer thread model. The consumer thread is
encapsulated in a class (eg: class consumer_thread), which has a member
function (eg: void consume(struct data)). The producer creates an "event"
object which is associated with the consumer_thread object, it's void
consume(struct data) member function, and the thread which must process the
data (consumer_thread). Now when the producer produces some data, it calls
event->post(data), which queues up an object which records the class
instance and it's member function which must be called with parameter
"data", and a shared_ptr to data. The consumer thread wakes up, gets the top
of the queue, and calls obj->mem_fun(data) --> ergo, mem_fun is called in
the correct thread context, and has the argument "data" to consume.

Does that make any sense? I don't think I'm explaining it well. Any
suggestions, (how to do what I'm asking for, or trashing my design and
offering a better design), would be greatly appreciated!

TIA
Steve

On 2 June 2010 19:06, Nat Goodspeed <nat_at_[hidden]> wrote:

> Steve Lorimer wrote:
>
>  I am wanting to write library code that will allow a user to create an
>> "event" which is associated with a thread, a class instance, and a member
>> function of that class. The user can then "post" data (generalised number of
>> arguments) - which results in the class instance's member function being
>> called in the context of the associated thread.
>>
>
> Steve, sorry if this is a stupid question, but by what delta does
> Boost.Signals2 fall short of your requirements?
>
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