php多线程有几种实现方法

function main(){ 
 
   $sql = "select waybill_id,order_id from waybill where status>40 order by update_time desc limit 10 "; 
 
    $data = Yii::app()->db->createCommand($sql)->queryAll(); //yii 框架格式 
 
    foreach ($data as $k => $v) {  
 
      if ($k % 2 == 0) { //偶数发一个网址 
 
        $send_data[$k]['url'] = ''; 
 
        $send_data[$k]['body'] = $v['waybill_id']; 
 
      } else { //奇数发送另外一个网址 
        $send_data[$k]['url'] = 'http://www.abc.com'; 
 
        $send_data[$k]['body']=array($v['order_id'] => array('extra' => 16)); 
      } 
    }  
  }

function sendStream() { 
    $english_format_number = number_format($number, 4, '.', ''); 
 
    echo $english_format_number;  
    exit(); 
    $timeout = 10; 
    $result = array(); 
    $sockets = array(); 
    $convenient_read_block = 8192; 
    $host = "test.local.com"; 
    $sql = "select waybill_id,order_id from xm_waybill where status>40 order by update_time desc limit 1 ";  
    $data = Yii::app()->db->createCommand($sql)->queryAll(); 
    $id = 0; 
 
    foreach ($data as $k => $v) { 
      if ($k % 2 == 0) { 
        $send_data[$k]['body'] = NoticeOrder::getSendData($v['waybill_id']); 
 
      } else { 
        $send_data[$k]['body'] = array($v['order_id'] => array('extra' => 16));  
      }  
      $data = json_encode($send_data[$k]['body']); 
      $s = stream_socket_client($host . ":80", $errno, $errstr, $timeout, STREAM_CLIENT_ASYNC_CONNECT | STREAM_CLIENT_CONNECT); 
      if ($s) {  
        $sockets[$id++] = $s; 
        $http_message = "GET /php/test.php?data=" . $data . " HTTP/1.0\r\nHost:" . $host . "\r\n\r\n";  
        fwrite($s, $http_message); 
      } else {  
        echo "Stream " . $id . " failed to open correctly."; 
      }  
    } 
 }

function daemon($func_name,$args,$number){ 
  while(true){ 
    $pid=pcntl_fork(); 
    if($pid==-1){ 
      echo "fork process fail"; 
      exit(); 
    }elseif($pid){//创建的子进程 
 
      static $num=0; 
      $num++; 
      if($num>=$number){ 
        //当进程数量达到一定数量时候，就对子进程进行回收。 
        pcntl_wait($status); 
 
        $num--; 
      }  
    }else{ //为0 则代表是子进程创建的，则直接进入工作状态 
 
      if(function_exists($func_name)){ 
        while (true) { 
          $ppid=posix_getpid(); 
          var_dump($ppid); 
          call_user_func_array($func_name,$args); 
          sleep(2); 
        } 
      }else{ 
        echo "function is not exists"; 
      } 
      exit();   
    } 
  } 
}  
function worker($args){  
  //do something 
 
}  
daemon('worker',array(1),2);