char *name is the name for the region of shared memory being created. The value of name must be unique to the program that calls the shmem_alloc() function or conflicts will occur.
int size is the number of characters of memory to be allocated for the shared memory.
int expose is either zero or nonzero. If nonzero, then on systems that support it, the file that is used to create the shared memory becomes visible to other processes running on the system.