Communicating between child and parent with shared memory
In this recipe, we'll learn how to use shared memory between two related processes—a parent and a child. Shared memory exists in various forms and can be used in different ways. In this book, we'll focus on the POSIX shared memory functions.
Shared memory in Linux can be used between related processes, as we are about to explore in this recipe, but also between unrelated processes using file descriptors to shared memory. When we use shared memory in this way, the memory is backed by a file in the /dev/shm
directory. We'll look at this in the next recipe.
In this recipe, we'll be using anonymous shared memory—memory not backed by a file.
Shared memory is just what it sounds like—a piece of memory that is shared between processes.
Knowing how to use shared memory will enable you to write more advanced programs.
Getting ready
For this recipe, you'll only need the GCC...