Sharing a serial port among multiple processes

[zacharoni16]

I am creating a Daemon in Unix that will have exclusive access to a serial port "/dev/tty01". I am planning to create a Master - Slave process paradigm where there is one master (the daemon) and multiple slaves.
I was thinking of having a structure in "Shared memory" where the slaves can access, and there is only one writer to the memory so I most likely wont need a semaphore. The data will be updated fairly slowly, once every minute for example.
I was looking into what would be the best possible way to do this, also if I have a structure in shared memory, how can I guarantee that the structure will be contiguous in memory? It is a requirement I must have.




The master program will have its own internal data structure that is being updated from the serial port, and then it will modify the data and send it out to a global structure that is in shared memory for the clients to use.


I dont have much experience in Unix IPC, but what would be the easiest way to do this? By the way the clients will all be different processes ran by other users locally on the system