单独程序的多对一双向通信

Question

I'm trying to make two-way many-to-one communication between programs in Linux.

My plan is the following: One program called "driver" that talks with the hardware needs to communicate with an unknown number of applications in Linux. I read that one of the most common ways for inter process communication is "named pipes".

The question I haven't found yet is: How new programs should notify the driver that a new program is running so that one more connection (named pipe) between the new program and the driver enstablished?

All programs will be written in C++

Answer 1

In essence, what you've described is a server/client relationship between programs; what each program does on either side of the communications bridge is probably irrelevant.

Even though these processes appear from the question to be intended to be on the same machine, networking is still available to you via localhost.

If you're not wedded to pipes, why not use a port for the driver (server) known to each program (client), to which the server listens?

That's pretty much the underlying philosophy of X-Windows, I believe.

Plus, there should be lots of reliable code out there to get you started.

Answer 2

I also think sockets may be a better solution, but if you really want named pipes, I'd do it this way:

The server opens a pipe named channel_request for reading. Any new client opens it for writing and writes a unique ID. (PID should work). The server reads this id and creates a named pipe called channel_[id] . The client then opens channel_[id] for reading and can start receiving data.

Note that linux pipes are unidirectional, so if you want two-way communications as shown in your diagram, you will need to open both a channel_[id]_out and a channel_[id]_in .