An alternative to IPC mechanism

What if the operating systems would not use any ipc mechanism in order to exchange the datas with each other,which technique could be an alternative for messaging between the processes?Do you guys think using the vfork () system call to duplicate processes is a logical solution for this problem?

vfork hardly seems a solution to the problem of communication in general. If IPC is unavailable, it's possible to create ad-hoc mutexes with temp files: open("/tmp/lockfile", O_CREAT|O_EXCL, 000) will only succeed for the process that gets to create the file. You could also exploit the queueing behavior of fifos. Or you could use sockets.

I think mutexes,fifos and sockets are both IPC methods.Most generally are there any specific way to do same things instead fifos, pipes and sockets?

Why do you ask? What is the goal? Is this a homework problem? Or idle curiosity? Knowing the bigger picture may help.

It was a homework, I still could not find any exact methods instead of using IPC's. If you have any idea about it,please let me know.