PHP socket_write 在非阻塞套接字循环中只有最后一次写入成功

Question

我希望通过套接字将数据发送到 2 个不同的端点。这是为了通过 WebSockets 和 Push-Services 发送消息(一个单独的工作实例)。由于我的应用程序不需要端点的响应，我将套接字设置为非阻塞，以便我的应用程序快速完成请求。

问题是，只有最后一个 socket_write 完成了。第一个端点不接收数据。

代码如下:

foreach ($workerInstances as $workerInstance) {
  // $workerInstance contains a hostname

  $sock=socket_create(AF_INET, SOCK_STREAM,SOL_TCP);
  socket_set_nonblock($sock);

  $connRes = socket_connect($sock, $workerInstance, 8018);
  if ($connRes) {
    $written = socket_write($sock, $data,strlen($data));
    socket_close($sock);

    if ($written === FALSE) {
      $result[] = $workerInstance . ': Connected but failed to write';
      ++$failures;
    } else {
      $result[] = $workerInstance . ': OK - ' . $written . ' bytes written';
    }

  } else {
    ++$failures;
    $result[]=$workerInstance . ': Failed';
  }
}

那么 $result 是:

[
    "app01.local: Connected but failed to write",
    "app02.local: OK - 63 bytes written"
]

我觉得非阻塞模式下socket_write的返回不靠谱吧？但是第一个端点确实没有收到任何数据。在阻塞模式下，两个端点都获取它们的数据。

我做错了什么？

Answer 1

在 http://php.net/manual/en/function.socket-connect.php#84465 上找到了解决方案

在非阻塞模式下，我必须等到套接字连接完成后才能写入套接字。因此，我们在循环中进行连接，直到结果不是 FALSE 或错误不是“正在连接”(或者我们等待足够长的时间以建立连接)。

foreach ($workerInstances as $workerInstance) {
  $sock = socket_create(AF_INET, SOCK_STREAM, SOL_TCP);
  socket_set_nonblock($sock);

  // wait until connection established
  $attempts = 30;
  while (!($connRes = socket_connect($sock, $workerInstance,
      8018)) && $attempts) {
    $error = socket_last_error();
    if ($error != SOCKET_EINPROGRESS && $error != SOCKET_EALREADY) {
      $result[] = $workerInstance . ' Socket connect error: ' . socket_strerror($error);
      break;
    } else {
      $result[] = $workerInstance . ' Connecting...';
    }

    usleep(1000);
    --$attempts;
  }


  if ($connRes) {
     $written = socket_write($sock, $data,strlen($data));

     if ($written === FALSE) {
        $result[] = $workerInstance . ': Connected but failed to write';
        ++$failures;
     } else {
        $result[] = $workerInstance . ': OK - ' . $written . ' bytes written';
     }

  } elseif ($attempts === 0) {
    ++$failures;
    $result[]=$workerInstance . ': Failed - Timeout!';

  } else {
    ++$failures;
    $result[]=$workerInstance . ': Failed';
  }
  socket_close($sock);
}

现在 $result 是

[
    "app01.local Connecting...",
    "app01.local: OK - 63 bytes written",
    "app02.local Connecting...",
    "app02.local: OK - 63 bytes written",
]