I am writing a set of programs on Linux that use shared memory. Currently I call shm_open() with a predetermined name for the shared memory. This works fine as I currently only have one set of processes running. If I want to have multiple, independent, set running I will need to have a unique filename per set.

Ideally I’m looking for something like mkstemp() or mkostemp(), but that works like shm_open().

If that’s not something that exists, the two potential options I see are:

1. Generate a “unique” filename, potentially based on the executable name and the process ID and use that in the call to shm_open(). Is there a way to get this to fail if the shared memory “file” already exists?
2. Use mkostemp() and then mmap() that file. Is there any real drawback to doing this? On Linux at least shm_open() seems to not have a physical backing file. Is it such a big deal to have on?