stream_select 和 pcntl_signal 有冲突？

[klggg]

调用了
pcntl_signal($signal, array(&$this, "handler"))
$mod_fd = stream_select($read,$write , $except , $tv_sec = 5);


运行后报如下错误，删除掉 pcntl_signal 后正常，请教是什么 原因，怎么解决 。


PHP Error[2]: stream_select(): unable to select [4]: 被中断的系统调用 (max_fd=10)

PHP 5.4.6-1ubuntu1.2 (cli) (built: Mar 11 2013 14:54:18)
Copyright (c) 1997-2012 The PHP Group
Zend Engine v2.4.0, Copyright (c) 1998-2012 Zend Technologies
with Xdebug v2.2.1, Copyright (c) 2002-2012, by Derick Rethans

        $signals = array(
                SIGCHLD => "SIGCHLD",
                SIGCLD	=> "SIGCLD",
                SIGINT  => "SIGINT",
                SIGHUP  => "SIGHUP",
                SIGQUIT => "SIGQUIT",
        );
        
        if (version_compare(phpversion(), "5.3.0", "lt")) {
            // tick use required as of PHP 4.3.0 
            declare(ticks = 1);
        }
        
        foreach ($signals as $signal => $name) {
            if (!pcntl_signal($signal, array(&$this, "handler"))) {
                die("Install signal handler for {$name} failed");
            }
        }

...

            $mod_fd = stream_select($read,$write , $except , $tv_sec = 5);

  public function handler($signo) {
        
        Yii::log("handler {$signo} ",CLogger::LEVEL_INFO, __METHOD__);
        
        switch(intval($signo)) {
            case SIGCLD:
            case SIGCHLD:
                
                Yii::log("SIGCHLD sub proccess   ",CLogger::LEVEL_TRACE, __METHOD__);
                //正常退出
                //declare = 1, that means one signal may be correspond multi-process die 
                while( ($pid = pcntl_wait($status, WNOHANG|WUNTRACED)) > 0 ) {
                    if (FALSE === pcntl_wifexited($status)) {
                        Yii::log("sub proccess {$pid} exited unormally with code {$status}",CLogger::LEVEL_WARNING, __METHOD__);
                    } else {
                        Yii::log("sub proccess {$pid} exited normally",CLogger::LEVEL_INFO, __METHOD__);
                    }
                    $this->_children--;
                }
                break;
            case SIGINT:
            case SIGQUIT:
            case SIGHUP:
                //异常退出
               $this->_cleanup();
                exit(0);
                break;
            default:
                break;
        }
    }