Pool Connection Pool

Sharing a single connection among multiple coroutines can lead to data confusion, so a connection pool is needed to manage resources like databases and Redis connections.

Tip
This feature requires workerman>=5.1.0

Note

• The underlying system automatically supports Swoole/Swow/Fiber/Select/Event driven
• When using Fiber/Select/Event driven with blocking extensions like PDO Redis, it automatically degrades to a connection pool with only one connection

Redis Connection Pool

<?php
use Workerman\Connection\TcpConnection;
use Workerman\Coroutine\Pool;
use Workerman\Events\Swoole;
use Workerman\Protocols\Http\Request;
use Workerman\Worker;
require_once __DIR__ . '/vendor/autoload.php';

class RedisPool
{

    private Pool $pool;

    public function __construct($host, $port, $max_connections = 10)
    {
        $this->pool = new Pool($max_connections);
        // Set the method to create connections for the connection pool
        $this->pool->setConnectionCreator(function () use ($host, $port) {
            $redis = new \Redis();
            $redis->connect($host, $port);
            return $redis;
        });
        // Set the method to destroy connections for the connection pool
        $this->pool->setConnectionCloser(function ($redis) {
            $redis->close();
        });
        // Set the heartbeat check method
        $this->pool->setHeartbeatChecker(function ($redis) {
            $redis->ping();
        });
    }

    // Get a connection
    public function get(): \Redis
    {
        return $this->pool->get();
    }

    // Return a connection
    public function put($redis): void
    {
        $this->pool->put($redis);
    }
}

// Http Server
$worker = new Worker('http://0.0.0.0:8001');
$worker->eventLoop = Swoole::class; // Or Swow::class or Fiber::class
$worker->onMessage = function (TcpConnection $connection, Request $request) {
    static $pool;
    if (!$pool) {
        $pool = new RedisPool('127.0.0.1', 6379, 10);
    }
    $redis = $pool->get();
    $redis->set('key', 'hello');
    $value = $redis->get('key');
    $pool->put($redis);
    $connection->send($value);
};

Worker::runAll();

MySQL Connection Pool (supports automatic acquisition and return of connections)

<?php
use Workerman\Connection\TcpConnection;
use Workerman\Coroutine\Context;
use Workerman\Coroutine;
use Workerman\Coroutine\Pool;
use Workerman\Events\Swoole;
use Workerman\Protocols\Http\Request;
use Workerman\Worker;
require_once __DIR__ . '/vendor/autoload.php';

class Db
{
    private static ?Pool $pool = null;

    public static function __callStatic($name, $arguments)
    {
        if (self::$pool === null) {
            self::initializePool();
        }
        // Retrieve the connection from the coroutine context to ensure the same coroutine uses the same connection
        $pdo = Context::get('pdo');
        if (!$pdo) {
            // Get a connection from the connection pool
            $pdo = self::$pool->get();
            Context::set('pdo', $pdo);
            // Automatically return the connection when the coroutine ends
            Coroutine::defer(function () use ($pdo) {
                self::$pool->put($pdo);
            });
        }
        return call_user_func_array([$pdo, $name], $arguments);
    }

    private static function initializePool(): void
    {
        self::$pool = new Pool(10);
        self::$pool->setConnectionCreator(function () {
            return new \PDO('mysql:host=127.0.0.1;dbname=your_database', 'your_username', 'your_password');
        });
        self::$pool->setConnectionCloser(function ($pdo) {
            $pdo = null;
        });
        self::$pool->setHeartbeatChecker(function ($pdo) {
            $pdo->query('SELECT 1');
        });
    }

}

// Http Server
$worker = new Worker('http://0.0.0.0:8001');
$worker->eventLoop = Swoole::class; // Or Swow::class or Fiber::class
$worker->onMessage = function (TcpConnection $connection, Request $request) {
    $value = Db::query('SELECT NOW() as now')->fetchAll();
    $connection->send(json_encode($value));
};

Worker::runAll();

Interface Description

interface PoolInterface
{

    /**
     * Constructor
     * @param int $max_connections Maximum number of connections, default is 1
     * @param array $config = [
     *    'min_connections' => 1, // Minimum number of connections, default is 1
     *    'idle_timeout' => 60, // Connection idle timeout (seconds), default is 60 seconds, connections will be destroyed and removed from the pool after 60 seconds
     *    'heartbeat_interval' => 50, // Heartbeat check interval (seconds), default is 50 seconds, checks if the connection is normal every 50 seconds
     *    'wait_timeout' => 10, // Wait timeout (seconds) for getting connections, default is 10 seconds, an exception will be thrown if the connection fails to be retrieved after 10 seconds
     * ] 
     */
    public function __construct(int $max_connections = 1, array $config = []);

    /**
     * Get a connection
     */
    public function get(): mixed;

    /**
     * Return a connection
     */
    public function put(object $connection): void;

    /**
     * Create a connection
     */
    public function createConnection(): object;

    /**
     * Close a connection and remove it from the pool
     */
    public function closeConnection(object $connection): void;

    /**
     * Get the current number of connections in the pool (including connections in use and unused connections)
     */
    public function getConnectionCount(): int;

    /**
     * Close connections in the pool (not including connections that are currently being used)
     */
    public function closeConnections(): void;

    /**
     * Set the method for creating connections in the connection pool
     */
    public function setConnectionCreator(callable $connectionCreateHandler): self;

    /**
     * Set the method for destroying connections in the connection pool
     */
    public function setConnectionCloser(callable $connectionDestroyHandler): self;

    /**
     * Set the heartbeat check method
     */
    public function setHeartbeatChecker(callable $connectionHeartbeatHandler): self;

}