Swoole 中使用 Lock 實現進程間鎖

注意：不要在 lock 和 unlock 操做中間使用可能引發協程切換的 API。

$lock = new Swoole\Lock(SWOOLE_MUTEX);
echo "[Master]create lock\n";
$lock->lock();

if (pcntl_fork() > 0)
{
    sleep(1);
    $lock->unlock();
} else {
    echo "[Child] Wait Lock\n";
    $lock->lock();
    echo "[Child] Get Lock\n";
    $lock->unlock();
    exit("[Child] exit\n");
}

echo "[Master]release lock\n";
unset($lock);
sleep(1);
echo "[Master]exit\n";