(PHP 4 >= 4.1.0, PHP 5, PHP 7, PHP 8)

sem_removeRimuove un semaforo


sem_remove(resource $sem_identifier): bool

La funzione sem_remove() rimuove il semaforo indicato da sem_identifier se questo è stato generato in orecedenza da sem_get(). In caso contrario si genera un messaggio di warning

Restituisce true in caso di successo, false in caso di fallimento.

Una volta rimosso, il semaforo non è più accessibile.

Vedere anche: sem_get(), sem_release() e sem_acquire().

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User Contributed Notes 1 note

donotcallme at iwillcallyou dot com
9 years ago
sem_remove() shouldn't be part of a normal cleanup/teardown and should be called very rarely due to bugs in the implementation.

It doesn't seem to hurt to leave semaphores lying around and is likely to be more performance-friendly to do so.  If you are concerned about having too many semaphores floating around for an application (e.g. a file cache that uses ftok()), you can use some modulus arithmetic and simple addition to create a limited range of values for your semaphores off in the middle of nowhere.  For example, ftok() % 101 + 0xBADBEEF.  Be sure to replace 0xBADBEEF with your own random value.  The example limits the range to 101 semaphores.  101 is a prime number - so if you want more or less, be sure to replace it with a prime number since primes theoretically help distribute values more evenly.
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