如何在子进程和父进程之间连续上下文切换？

I am trying to write a program in C based on the concept of shared memory. I am creating two shared memory and creating two processes using the fork() function. I want one of the process to write into one of the shared memory and the other to read from it and vice versa with the other shared memory. I don't want to use pipes. How can i context switch between the two processes continuosly so that I can read from one and write from the other?I am trying to write a program in C based on th