PHPのお勉強！

PHP TOP
PHP 8.4.2 Released!

    SyncMutex::unlock

    (PECL sync >= 1.0.0)

    SyncMutex::unlock — Unlocks the mutex

    説明

    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.

    パラメータ

    all

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

    戻り値

    成功した場合に true を、失敗した場合に false を返します。

    例

    例1 SyncMutex::unlock() example

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

    $mutex->lock();

    /* ... */

    $mutex->unlock();
    ?>

    参考

    Found A Problem?

    Learn How To Improve This Page • Submit a Pull Request • Report a Bug
    ＋add a note

    User Contributed Notes 1 note

    up
    4
    npelov at croler dot net
    4 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
    ＋add a note
    To Top