Sharing memory between processes through the use of mmap()

Question

I\'m in Linux 2.6. I have an environment where 2 processes simulate (using shared memory) the exchange of data through a simple implementation of the message passing mode.

Answer 1

Is it possible to attach that region of memory to the server POST forking, after the client creates it?

MAP_ANONYMOUS|MAP_SHARED mapped memory can only be accessed by the process which does that mmap() call or its child processes. There is no way for another process to map the same memory because that memory can not be referred to from elsewhere since it is anonymous.

Using shm_open() call it is possible to create named shared memory which can be referred to and mapped by unrelated processes.