Re: [boost] boost.shmem bugs

From: Ion Gaztañaga (igaztanaga_at_[hidden])
Date: 2006-07-08 13:46:52

Hi,

> But at the current moment I'm very interesting in adding of more 
> features to shared_message_queue class. As I understood this queue 
> supplies only one client-server connection. So one message can be 
> received only one time despite of many processes that want to read it. 
> It seems to have internal client number counter will be a good idea.

You want the queue to have an internal client number so that a message 
should be read N times before it's removed from the queue? I've based my 
model on POSIX mq_xxx functions that offer this possibility. I a 
reference counted message quite dangerous because a process crash would 
block the queue indefinitely. I don't see an strong reason to do this. 
If you want a robust server<->multi-client communication, I would create 
N message queues just like a web server has a connection with each web 
client. If a client crashes, the server and the other clients are still 
fine. If a timeout expires you could even erase the used message queue 
system wide erasing the shared memory that was used for that message 
queue. This multiplies the number of sent/received messages, and makes 
the application more complicated, though.

> Second feature I want to ask you it add more service methods - like to 
> get number of messages in queue (useful for profiling applications at 
> hard data traffic).

Interesting, I will try to add it.

Ion