CascadiaPHP 2024


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

sem_removeRemove a semaphore


sem_remove(SysvSemaphore $semaphore): bool

sem_remove() removes the given semaphore.

After removing the semaphore, it is no longer accessible.

Bağımsız Değişkenler


A semaphore as returned by sem_get().

Dönen Değerler

Başarı durumunda true, başarısızlık durumunda false döner.

Sürüm Bilgisi

Sürüm: Açıklama
8.0.0 semaphore expects a SysvSemaphore instance now; previously, a resource was expected.

Ayrıca Bakınız

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User Contributed Notes 1 note

donotcallme at iwillcallyou dot com
10 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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