PHP编程中尝试程序并发的几种方式总结

5年以前 | 阅读数：377 次 | 编程语言：PHP

本文大约总结了PHP编程中的五种并发方式：
1.curl_multi_init
文档中说的是 Allows the processing of multiple cURL handles asynchronously. 确实是异步。这里需要理解的是select这个方法，文档中是这么解释的Blocks until there is activity on any of the curl_multi connections.。了解一下常见的异步模型就应该能理解，select, epoll，都很有名


    <?php
    // build the individual requests as above, but do not execute them
    $ch_1 = curl_init('http://www.jb51.net/');
    $ch_2 = curl_init('http://www.jb51.net/');
    curl_setopt($ch_1, CURLOPT_RETURNTRANSFER, true);
    curl_setopt($ch_2, CURLOPT_RETURNTRANSFER, true);

    // build the multi-curl handle, adding both $ch
    $mh = curl_multi_init();
    curl_multi_add_handle($mh, $ch_1);
    curl_multi_add_handle($mh, $ch_2);

    // execute all queries simultaneously, and continue when all are complete
    $running = null;
    do {
      curl_multi_exec($mh, $running);
      $ch = curl_multi_select($mh);
      if($ch !== 0){
        $info = curl_multi_info_read($mh);
        if($info){
          var_dump($info);
          $response_1 = curl_multi_getcontent($info['handle']);
          echo "$response_1 \n";
          break;
        }
      }
    } while ($running > 0);

    //close the handles
    curl_multi_remove_handle($mh, $ch_1);
    curl_multi_remove_handle($mh, $ch_2);
    curl_multi_close($mh);

这里我设置的是，select得到结果，就退出循环，并且删除 curl resource, 从而达到取消http请求的目的。

2.swoole_client
swoole_client提供了异步模式，我竟然把这个忘了。这里的sleep方法需要swoole版本大于等于1.7.21, 我还没升到这个版本，所以直接exit也可以。


    <?php
    $client = new swoole_client(SWOOLE_SOCK_TCP, SWOOLE_SOCK_ASYNC);
    //设置事件回调函数
    $client->on("connect", function($cli) {
      $req = "GET / HTTP/1.1\r\n
      Host: www.jb51.net\r\n
      Connection: keep-alive\r\n
      Cache-Control: no-cache\r\n
      Pragma: no-cache\r\n\r\n";

      for ($i=0; $i < 3; $i++) {
        $cli->send($req);
      }
    });
    $client->on("receive", function($cli, $data){
      echo "Received: ".$data."\n";
      exit(0);
      $cli->sleep(); // swoole >= 1.7.21
    });
    $client->on("error", function($cli){
      echo "Connect failed\n";
    });
    $client->on("close", function($cli){
      echo "Connection close\n";
    });
    //发起网络连接
    $client->connect('183.207.95.145', 80, 1);

3.process
哎，竟然差点忘了 swoole_process, 这里就不用 pcntl 模块了。但是写完发现，这其实也不算是中断请求，而是哪个先到读哪个，忽视后面的返回值。


    <?php

    $workers = [];
    $worker_num = 3;//创建的进程数
    $finished = false;
    $lock = new swoole_lock(SWOOLE_MUTEX);

    for($i=0;$i<$worker_num ; $i++){
      $process = new swoole_process('process');
      //$process->useQueue();
      $pid = $process->start();
      $workers[$pid] = $process;
    }

    foreach($workers as $pid => $process){
      //子进程也会包含此事件
      swoole_event_add($process->pipe, function ($pipe) use($process, $lock, &$finished) {
        $lock->lock();
        if(!$finished){
          $finished = true;
          $data = $process->read();
          echo "RECV: " . $data.PHP_EOL;
        }
        $lock->unlock();
      });
    }

    function process(swoole_process $process){
      $response = 'http response';
      $process->write($response);
      echo $process->pid,"\t",$process->callback .PHP_EOL;
    }

    for($i = 0; $i < $worker_num; $i++) {
      $ret = swoole_process::wait();
      $pid = $ret['pid'];
      echo "Worker Exit, PID=".$pid.PHP_EOL;
    }

4.pthreads
编译pthreads模块时，提示php编译时必须打开ZTS, 所以貌似必须 thread safe 版本才能使用. wamp中多php正好是TS的，直接下了个dll, 文档中的说明复制到对应目录，就在win下测试了。还没完全理解，查到文章说 php 的 pthreads 和 POSIX pthreads是完全不一样的。代码有些烂，还需要多看看文档，体会一下。


    <?php
    class Foo extends Stackable {
      public $url;
      public $response = null;
      public function __construct(){
        $this->url = 'http://www.jb51.net';
      }
      public function run(){}
    }

    class Process extends Worker {
      private $text = "";
      public function __construct($text,$object){
        $this->text = $text;
        $this->object = $object;
      }
      public function run(){
        while (is_null($this->object->response)){
          print " Thread {$this->text} is running\n";
          $this->object->response = 'http response';
          sleep(1);
        }
      }
    }

    $foo = new Foo();

    $a = new Process("A",$foo);
    $a->start();

    $b = new Process("B",$foo);
    $b->start();

    echo $foo->response;

5.yield
以同步方式书写异步代码：


    <?php 

    class AsyncServer { 
      protected $handler; 
      protected $socket; 
      protected $tasks = []; 
      protected $timers = []; 

      public function __construct(callable $handler) { 
        $this->handler = $handler; 

        $this->socket = socket_create(AF_INET, SOCK_DGRAM, SOL_UDP); 
        if(!$this->socket) { 
          die(socket_strerror(socket_last_error())."\n"); 
        } 
        if (!socket_set_nonblock($this->socket)) { 
          die(socket_strerror(socket_last_error())."\n"); 
        } 
        if(!socket_bind($this->socket, "0.0.0.0", 1234)) { 
          die(socket_strerror(socket_last_error())."\n"); 
        } 
      } 

      public function Run() { 
        while (true) { 
          $now = microtime(true) * 1000; 
          foreach ($this->timers as $time => $sockets) { 
            if ($time > $now) break; 
            foreach ($sockets as $one) { 
              list($socket, $coroutine) = $this->tasks[$one]; 
              unset($this->tasks[$one]); 
              socket_close($socket); 
              $coroutine->throw(new Exception("Timeout")); 
            } 
            unset($this->timers[$time]); 
          } 

          $reads = array($this->socket); 
          foreach ($this->tasks as list($socket)) { 
            $reads[] = $socket; 
          } 
          $writes = NULL; 
          $excepts= NULL; 
          if (!socket_select($reads, $writes, $excepts, 0, 1000)) { 
            continue; 
          } 

          foreach ($reads as $one) { 
            $len = socket_recvfrom($one, $data, 65535, 0, $ip, $port); 
            if (!$len) { 
              //echo "socket_recvfrom fail.\n"; 
              continue; 
            } 
            if ($one == $this->socket) { 
              //echo "[Run]request recvfrom succ. data=$data ip=$ip port=$port\n"; 
              $handler = $this->handler; 
              $coroutine = $handler($one, $data, $len, $ip, $port); 
              if (!$coroutine) { 
                //echo "[Run]everything is done.\n"; 
                continue; 
              } 
              $task = $coroutine->current(); 
              //echo "[Run]AsyncTask recv. data=$task->data ip=$task->ip port=$task->port timeout=$task->timeout\n"; 
              $socket = socket_create(AF_INET, SOCK_DGRAM, SOL_UDP); 
              if(!$socket) { 
                //echo socket_strerror(socket_last_error())."\n"; 
                $coroutine->throw(new Exception(socket_strerror(socket_last_error()), socket_last_error())); 
                continue; 
              } 
              if (!socket_set_nonblock($socket)) { 
                //echo socket_strerror(socket_last_error())."\n"; 
                $coroutine->throw(new Exception(socket_strerror(socket_last_error()), socket_last_error())); 
                continue; 
              } 
              socket_sendto($socket, $task->data, $task->len, 0, $task->ip, $task->port); 
              $deadline = $now + $task->timeout; 
              $this->tasks[$socket] = [$socket, $coroutine, $deadline]; 
              $this->timers[$deadline][$socket] = $socket; 
            } else { 
              //echo "[Run]response recvfrom succ. data=$data ip=$ip port=$port\n"; 
              list($socket, $coroutine, $deadline) = $this->tasks[$one]; 
              unset($this->tasks[$one]); 
              unset($this->timers[$deadline][$one]); 
              socket_close($socket); 
              $coroutine->send(array($data, $len)); 
            } 
          } 
        } 
      } 
    } 

    class AsyncTask { 
      public $data; 
      public $len; 
      public $ip; 
      public $port; 
      public $timeout; 

      public function __construct($data, $len, $ip, $port, $timeout) { 
        $this->data = $data; 
        $this->len = $len; 
        $this->ip = $ip; 
        $this->port = $port; 
        $this->timeout = $timeout; 
      } 
    } 

    function AsyncSendRecv($req_buf, $req_len, $ip, $port, $timeout) { 
      return new AsyncTask($req_buf, $req_len, $ip, $port, $timeout); 
    } 

    function RequestHandler($socket, $req_buf, $req_len, $ip, $port) { 
      //echo "[RequestHandler] before yield AsyncTask. REQ=$req_buf\n"; 
      try { 
        list($rsp_buf, $rsp_len) = (yield AsyncSendRecv($req_buf, $req_len, "127.0.0.1", 2345, 3000)); 
      } catch (Exception $ex) { 
        $rsp_buf = $ex->getMessage(); 
        $rsp_len = strlen($rsp_buf); 
        //echo "[Exception]$rsp_buf\n"; 
      } 
      //echo "[RequestHandler] after yield AsyncTask. RSP=$rsp_buf\n"; 
      socket_sendto($socket, $rsp_buf, $rsp_len, 0, $ip, $port); 
    } 

    $server = new AsyncServer(RequestHandler); 
    $server->Run(); 

    ?>

代码解读：

借助PHP内置array能力，实现简单的"超时管理"，以毫秒为精度作为时间分片；
封装AsyncSendRecv接口，调用形如yield AsyncSendRecv()，更加自然；
添加Exception作为错误处理机制，添加ret_code亦可，仅为展示之用。