when using shared memory in unix

When you code a data supplier app in C 开发者_如何转开发for Unix that uses shared memory when do you detach the shared memory only when the server exits or when you are finished updating the shared memory ?

AFAIK, keeping it attached will not bother.

However since the attachment tracks the number of processes attached, if that count is >0, then you won't be allowed to destroy your shm until that count get back to 0 (in other words when all process are detached). If you have a main process attached, I'm not sure you will be able to destroy it from an external "administrative" process for you shm.

In my personnal experience, I don't detach the SHM after write operations, only at process exit.