php socket如何设置超时

//如果$waitAckSec=0，则返回成功发送的字节
 //如果$waitAckSec大于0，则返回发送后接收到得内容
 //任何情况下，失败都返回FALSE
 function sendUdp($host, $port, $buff,$waitAckSec=0) {
 $socket = ($result = @socket_create(AF_INET,SOCK_DGRAM,SOL_UDP));
 //发送超时1秒
 socket_set_option($socket,SOL_SOCKET,SO_RCVTIMEO,array("sec"=>3, "usec"=>0 ) );
 //接收超时6秒
 socket_set_option($socket,SOL_SOCKET,SO_SNDTIMEO,array("sec"=>6, "usec"=>0 ) );
 if($socket){
 $result = @socket_sendto($socket,$buff,strlen($buff),0,$host,$port);
 if($waitAckSec>0){
 $result = FALSE;
 $read = array($socket);
 $write = NULL;
 $except = NULL;
 if(@socket_select($read,$write,$except,$waitAckSec)>0){
 $fromHost = "";
 $fromPort = 0;
 @socket_recvfrom($socket,$result,4096,0,$fromHost,$fromPort);
 $result = phpext_unpack($result);
 if($result["needAck"] == 1){
 $this->sendUdp($host, $port, $result["ackdata"]);
 if(isset ($result['data']['list']) && isset ($result['data']['totalCount'])){
 $list = $result['data']['list'];
 $count = $result['data']['totalCount'];
 while($count> count($list)){
 @socket_recvfrom($socket,$result_temp,4096,0,$fromHost,$fromPort);
 $result_temp = phpext_unpack($result_temp);
 $this->sendUdp($host, $port, $result_temp["ackdata"]);
 $list = array_merge($list,$result_temp['data']['list']);
 }
 $result['data']['list'] = $list;
 }
 }else{
 @socket_recvfrom($socket,$result,4096,0,$fromHost,$fromPort);
 $result = phpext_unpack($result);
 if($result["needAck"] == 1){
 $this->sendUdp($host, $port, $result["ackdata"]);
 if(isset ($result['data']['result']) && isset ($result['data']['userID'])){
 $list = $result['data']['list'];
 $count = $result['data']['totalCount'];
 while($count> count($list)){
 @socket_recvfrom($socket,$result_temp,4096,0,$fromHost,$fromPort);
 $result_temp = phpext_unpack($result_temp);
 $this->sendUdp($host, $port, $result_temp["ackdata"]);
 $list = array_merge($list,$result_temp['data']['list']);
 }
 $result['data']['list'] = $list;
 }
 }
 }
 }else{
 $result = SEND_UDP_ERROR;
 }
 }
 @socket_close($socket);
 }
 return $result;
 }