PHP code example of malkusch / lock

    
        
<?php
require_once('vendor/autoload.php');

/* Start to develop here. Best regards https://php-download.com/ */

    

malkusch / lock example snippets

$newBalance = $mutex->synchronized(function () use (
    $bankAccount,
    $amount
): int {
    $balance = $bankAccount->getBalance();
    $balance -= $amount;
    if ($balance < 0) {
        throw new \DomainException('You have no credit.');
    }
    $bankAccount->setBalance($balance);

    return $balance;
});

$newBalance = $mutex->check(function () use ($bankAccount, $amount): bool {
    return $bankAccount->getBalance() >= $amount;
})->then(function () use ($bankAccount, $amount): int {
    $balance = $bankAccount->getBalance();
    $balance -= $amount;
    $bankAccount->setBalance($balance);

    return $balance;
});

if (false === $newBalance) {
    if ($balance < 0) {
        throw new \DomainException('You have no credit.');
    }
}

try {
    // or $mutex->check(...)
    $result = $mutex->synchronized(function () {
        if (someCondition()) {
            throw new \DomainException();
        }

        return "result";
    });
} catch (LockReleaseException $unlockException) {
    if ($unlockException->getCodeException() !== null) {
        $codeException = $unlockException->getCodeException()
        // do something with the code exception
    } else {
        $code_result = $unlockException->getCodeResult();
        // do something with the code result
    }

    // deal with LockReleaseException or propagate it
    throw $unlockException;
}

$mutex = new CASMutex();
$mutex->synchronized(function () use ($memcached, $mutex, $amount): void {
    $balance = $memcached->get("balance", null, $casToken);
    $balance -= $amount;
    if (!$memcached->cas($casToken, "balance", $balance)) {
        return;
    }
    $mutex->notify();
});

$mutex = new FlockMutex(fopen(__FILE__, "r"));
$mutex->synchronized(function () use ($bankAccount, $amount) {
    $balance = $bankAccount->getBalance();
    $balance -= $amount;
    if ($balance < 0) {
        throw new \DomainException("You have no credit.");
    }
    $bankAccount->setBalance($balance);
});

$memcache = new \Memcached();
$memcache->addServer("localhost", 11211);

$mutex = new MemcachedMutex("balance", $memcache);
$mutex->synchronized(function () use ($bankAccount, $amount) {
    $balance = $bankAccount->getBalance();
    $balance -= $amount;
    if ($balance < 0) {
        throw new \DomainException("You have no credit.");
    }
    $bankAccount->setBalance($balance);
});

$redis = new Redis();
$redis->connect("localhost");

$mutex = new PHPRedisMutex([$redis], "balance");
$mutex->synchronized(function () use ($bankAccount, $amount) {
    $balance = $bankAccount->getBalance();
    $balance -= $amount;
    if ($balance < 0) {
        throw new \DomainException("You have no credit.");
    }
    $bankAccount->setBalance($balance);
});

$redis = new Client("redis://localhost");

$mutex = new PredisMutex([$redis], "balance");
$mutex->synchronized(function () use ($bankAccount, $amount) {
    $balance = $bankAccount->getBalance();
    $balance -= $amount;
    if ($balance < 0) {
        throw new \DomainException("You have no credit.");
    }
    $bankAccount->setBalance($balance);
});

$semaphore = sem_get(ftok(__FILE__, "a"));
$mutex = new SemaphoreMutex($semaphore);
$mutex->synchronized(function () use ($bankAccount, $amount) {
    $balance = $bankAccount->getBalance();
    $balance -= $amount;
    if ($balance < 0) {
        throw new \DomainException("You have no credit.");
    }
    $bankAccount->setBalance($balance);
});

$mutex = new TransactionalMutex($pdo);
$mutex->synchronized(function () use ($pdo, $accountId, $amount) {
    $select = $pdo->prepare(
        "SELECT balance FROM account WHERE id = ? FOR UPDATE"
    );
    $select->execute([$accountId]);
    $balance = $select->fetchColumn();

    $balance -= $amount;
    if ($balance < 0) {
        throw new \DomainException("You have no credit.");
    }
    $pdo->prepare("UPDATE account SET balance = ? WHERE id = ?")
        ->execute([$balance, $accountId]);
});

$pdo = new PDO("mysql:host=localhost;dbname=test", "username");

$mutex = new MySQLMutex($pdo, "balance", 15);
$mutex->synchronized(function () use ($bankAccount, $amount) {
    $balance = $bankAccount->getBalance();
    $balance -= $amount;
    if ($balance < 0) {
        throw new \DomainException("You have no credit.");
    }
    $bankAccount->setBalance($balance);
});

$pdo = new PDO("pgsql:host=localhost;dbname=test;", "username");

$mutex = new PgAdvisoryLockMutex($pdo, "balance");
$mutex->synchronized(function () use ($bankAccount, $amount) {
    $balance = $bankAccount->getBalance();
    $balance -= $amount;
    if ($balance < 0) {
        throw new \DomainException("You have no credit.");
    }
    $bankAccount->setBalance($balance);
});