Semaphore/Shared-memory ID keys

> > Maybe you ran out of ID's? Try ipcs -a to see all of your IPC stuff. Each > > system has a limited amount of resources. It is my understanding that PHP does not provide any mechanism to verify the uniqueness of a user's choice in semaphore/shared-memory ID keys. I always assumed that was because it was impossible to do so. Yet, if "ipcs -a" is capable of doing it, should not PHP also be "easily" able to do it, and provide functionality for this express purpose? I say this blithely, not knowing how tricky it would be to actually write the function, or even if it's been added while I wasn't looking, or if there's something more complicated in semaphore/shared-memory that I just don't grok yet that makes this a dumb idea in the first place :-)