enhancementgood first issue
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Description
From manual page: https://php.net/function.sem-get
sem_get() has an important gotcha where if the variable is freed then the semaphore is released. I propose this is not quite a bug but could do with a red warning box e.g.
Warning: sem_get will also
auto_releasethe semaphore when the variable which holds it is freed (rather than the process ending). Ensure you store the result in a variable which is not overwritten, unset, or goes out of scope while the semaphore should be alive.
This behaviour can be demonstrated with the following:
$semGet = sem_get(1);
var_dump(sem_acquire($semGet, true));
// true: semaphore(1) acquired
var_dump(sem_acquire(sem_get(1), true));
// false: semaphore(1) already acquired
unset($semGet);
var_dump(sem_acquire(sem_get(1), true));
// true: semaphore(1) released by variable unset() so can be acquired again