is there ipc mechnisms to implement onepoint to multiipoint?

process A want to send some data to some process, but A dont know how many exactly process there are.

There is no true multipoint or broadcast aside UDP. That being said it’s possible by scanning the /dev/name/global/… to find all the process that have you have to talk to given they attached a name.

Also you could have the other processes register their presence to process A.

In all cases their is no way with QNX native networking to send a single message to every process.

Have you tried the new PPS (Persistent Publish Subscribe) thing from QNX? Not sure if it’s part of 6.4 but it should be in 6.5 pre-release. With it, you can Publish data objects and don’t need to worry if there is one, two, or a dozen of receivers (subscribers). At least, as far as I understood it. :slight_smile:

In their announcement they made a big deal about it. I’m curious to know more about what it does. Does persistent mean across boots? Sounds so far just like a resource manager that you can save and retrieve things from. which would not be a big deal.

Ehm, Microsoft made a big deal out of Windows 7, although it’s nothing special. So what do you expect from QNX! :slight_smile:

In the old days, everyone was complaining how bad QNX marketing was. Now there playing the game ;-)

So Thunder and Mario, you are saying that yes, it is not a big deal?

I don’t think it is a big deal, technically. But it’s useful and good that you don’t have to write it on your own. And it’s good that QNX did it, because from an earlier post, you could draw the wrong conclusion that a multi-receiver/single-sender, or single-receiver/multi-sender scenario is not possible, or would be hard to do. It’s not. It easy, and it’s there. Just go and use it. No big deal. :slight_smile:

I do not think it’s a big deal but it’s a nice tool to have in the tool box.

And I believe it can be “persistent” cross boot, as long as you have persistent storage in the system.

It would be nice to store current status and be able to retrieve it after boot. Very useful for a Car or a Cell Phone. :slight_smile:

It’s a beefed up version of ds. A few years back I asked for the source to ds to add persitent capability to it, I was told to write my own.

What’s “ds”?

It stands for Data Server, it’s been there for a while. I believe it’s available under QNX4 as well. The server comes with its api ds_*() for setting getting sharing variable between processes. They have to be on the same machine though.