sem_remove
(PHP 4 >= 4.1.0, PHP 5, PHP 7, PHP 8)
sem_remove — セマフォを削除する
説明
sem_remove() は、指定したセマフォを削除します。
セマフォを削除した後、そのセマフォにはもうアクセスできません。
変更履歴
| バージョン | 説明 |
|---|---|
| 8.0.0 |
引数 semaphore は、
SysvSemaphore クラスのインスタンスを期待するようになりました。
これより前のバージョンでは、リソースが期待されていました。
|
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User Contributed Notes 1 note
donotcallme at iwillcallyou dot com ¶
11 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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