PHP高并发处理中的数据库连接池优化方案

class ConnectionPool {
  private $pool; // 连接池数组
  private $maxSize; // 最大连接数
  private $currentSize; // 当前连接数

  public function __construct($maxSize) {
    $this->maxSize = $maxSize;
    $this->currentSize = 0;
    $this->pool = [];
  }

  public function getConnection() {
    // 如果连接池中有可用连接，则直接返回
    if (!empty($this->pool)) {
      return array_pop($this->pool);
    }

    // 如果连接池中没有可用连接，而且当前连接数还未达到最大值，则创建新的连接
    if ($this->currentSize < $this->maxSize) {
      $connection = $this->createConnection();
      $this->currentSize++;
      return $connection;
    }

    // 如果连接池中没有可用连接，而且当前连接数已达到最大值，则等待，并重试
    while (empty($this->pool)) {
      sleep(1);
    }
    return array_pop($this->pool);
  }

  public function releaseConnection($connection) {
    // 释放连接，并将连接加入连接池中
    $this->pool[] = $connection;
  }

  private function createConnection() {
    // 创建新的数据库连接
    $connection = new PDO('mysql:host=localhost;dbname=test', 'root', 'password');
    return $connection;
  }
}

class DatabaseTest {
  public function __construct($maxRequests) {
    $pool = new ConnectionPool(10); // 创建连接池
    $this->test($pool, $maxRequests);
  }

  private function test($pool, $maxRequests) {
    $requestCount = 0;
    while ($requestCount < $maxRequests) {
      // 模拟高并发访问数据库的逻辑
      $connection = $pool->getConnection();
      $result = $connection->query('SELECT * FROM users');
      // 处理查询结果...
      $pool->releaseConnection($connection);
      
      $requestCount++;
    }
  }
}

$test = new DatabaseTest(100); // 创建一个并发请求数为100的测试类