PHP Pthreads - 使用 mysqli

Question

我第一次尝试在我的 Web 应用程序中使用 pthreads。我有 pthreads 为简单的测试用例工作，但是我无法让 pthreads 中的 mysql 查询工作。这是我的 php 文件:

class SqlThread extends Thread
{
    private $dbc;
    public $log;
    public $return;

    public function __construct(){
        $this->dbc = mysqli_connect("localhost", "root", "rootpassword", "my_database");

        $this->log = "<br>(".__LINE__.") construct finished.";
    }

    //gets called when thread is started
    public function run(){
        $val = $this->testSqlCall();

        $this->log .= "<br>(".__LINE__.") testSqlCall() has finished";

        $this->return = $val;
    }

    /**
     * testing sql queries
     */
    function testSqlCall(){

        $sql = "SELECT *
                FROM client_detail";

        $this->log .= "<br>(".__LINE__.") testSqlCall() - sql: ".$sql;

        $r= @mysqli_query($this->dbc,$sql);
        $num = mysqli_affected_rows($this->dbc);

        $this->log .= "<br>(".__LINE__.") testSqlCall() - total number of returned rows: ".$num;

        return $num;

    }
}

/**
 * threaded test
 */
$thread = new SqlThread();
$thread->start();
$thread->join();

echo "<br><br><br>thread return value:";
var_dump($thread->return);
echo $thread->log;

/**
 * same test, but not threaded
 */

$dbc = mysqli_connect("localhost", "root", "rootpassword", "my_database");
$sql = "SELECT *
        FROM client_detail";
$r = @mysqli_query($dbc,$sql);
$num = mysqli_affected_rows($dbc);
echo "<br><br> --- non-threaded return value: $num";

这是它返回的内容:

thread return value:

null


(12) construct finished.
(32) testSqlCall() - sql: SELECT * FROM client_detail
(37) testSqlCall() - total number of returned rows:
(19) testSqlCall() has finished

--- non-threaded return value: 39276

如您所见，SqlThread 中的 mysqli 查询不返回任何内容，而 SqlThread 类之外的完全相同的查询返回我所期望的结果。

有什么想法吗？有没有人在 php 线程中得到 sql 查询来工作？

Answer 1

问题是mysqli对象不适合在多线程中使用，你想为你启动的每个线程创建一个MySQLi实例，这样每个线程都有一个唯一的连接。

<?php
define("SQLHOST", "localhost");
define("SQLUSER", "root");
define("SQLPASS", "");
define("SQLDB",   "test");
define("SQLPORT", 3306);
define("SQLSOCK", "/var/lib/mysql/mysql.sock");

class Mine extends Thread {
    public function run() {
        try {
            $my = new mysqli(SQLHOST, SQLUSER, SQLPASS, SQLDB, SQLPORT, SQLSOCK);
            if ($my) {
                $result = $my->query("SHOW DATABASES;");

                if (is_object($result)) {
                    while (($row = $result->fetch_assoc())) {
                        var_dump($row);
                    }
                }
            }
        } catch(Exception $ex) {
            var_dump($ex);
        }
    }
}

$mine = new Mine();
$mine->start();
?>

产量

array(1) {
  ["Database"]=>
  string(18) "information_schema"
}
array(1) {
  ["Database"]=>
  string(5) "mysql"
}
array(1) {
  ["Database"]=>
  string(18) "performance_schema"
}
array(1) {
  ["Database"]=>
  string(4) "test"
}

请注意，MySQLi 对象永远不会存储在 Threads 对象范围内，因为您应该只将您打算共享的对象存储在对象范围内，并且由于您不能共享 MySQLi 连接，因此最好在方法范围。

github上有很多例子，包括一个SQLWorker的例子，你应该读一读。

进一步阅读:https://gist.github.com/krakjoe/6437782