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SyncMutex::unlock

(PECL sync >= 1.0.0)

SyncMutex::unlockUnlocks the mutex

Beschreibung

public SyncMutex::unlock(bool $all = false): bool

Decreases the internal counter of a SyncMutex object. When the internal counter reaches zero, the actual lock on the object is released.

Parameter-Liste

all

Specifies whether or not to set the internal counter to zero and therefore release the lock.

Rückgabewerte

Gibt bei Erfolg true zurück. Bei einem Fehler wird false zurückgegeben.

Beispiele

Beispiel #1 SyncMutex::unlock() example

<?php
$mutex
= new SyncMutex("UniqueName");

$mutex->lock();

/* ... */

$mutex->unlock();
?>

Siehe auch

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User Contributed Notes 1 note

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npelov at croler dot net
3 years ago
If the php process dies unexpectedly (on linux) the lock will remain with no option to remove it. unlock() will not work if the lock is being held by other process. SyncMutex uses shared mem. in that case you can delete the shared memory object in /dev/shm. To list the objects:

ls /dev/shm/Sync_Mutex*

Keep in mind that objects remain there even after unlocking. So if you use lots of random mutex names then the number of these objects will grow and and you might want to cleanup at some point

Example sync.php:
<?php

$s
= new SyncMutex("mymutex");

if(!
$s->lock()){
echo
"cannot lock\n";
exit;
}
echo
"locked\n";
sleep(10);
$s->unlock();
echo
"unlocked\n";
?>

then run:

php -f sync.php

and press ctrl-c. If you run it again it won't lock. So what you can do is:

rm -f /dev/shm/Sync_Mutex-*-mymutex

Then run it again - it'll lock again
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