Re: [PHP4BETA] Questions on sem_* and shm_* functions

SB>> - What is the perm argument of sem_get() and shm_attach() for? Is SB>> this, too, needed to be emulated? For shmget that's permissions. Manual says this: mode_flags (lowest 9 bits) specifying the permissions granted to the owner, group, and world. Presently, the exe- cute permissions are not used by the system. SB>> - What does shm_attach() return if for some reason the creation or SB>> opening of a shared memory segment fails? Although it is unlikely SB>> that this may happen with nmy fake shared memory implementation, as SB>> the variables are held in a SQL table instead of RAM. From the code I see it returns false on failure. SB>> - Is it true that shm_detach() only removes the shm_identifier for a SB>> shared memory segment from some sort of list but doesn't remove the SB>> stored variables of that segement? Not exactly. If reference count for this segment for the script reaches 0, it calls shmdt, detaching this segment. SB>> - How do the functions shm_get_var() and shm_remove_var() behave if SB>> the given shared memory segment and / or variable doesn't exist? They return false and issue warning. SB>> - How do the functions shm_detach() and shm_remove() behave if SB>> the given shared memory segment doesn't exist? shm_detach have no checks. _remove returns false on error. SB>> - How do the functions sem_acquire() and sem_release() behave if the SB>> given semaphore doesn't exist? They return false and print warning if something bad happens. -- Stanislav Malyshev stas@zend.com +972-3-6139665