[PHP] socket客户端时的超时问题

for($i=0;$i<1000;$i++){
    $sock=stream_socket_client("www.baidu.com:80", $errno,$errstr,2);  
    stream_set_timeout($sock,5); 
    $meta=stream_get_meta_data($sock);

    var_dump("start",$meta);
    fwrite($sock, "GET / HTTP/1.0\r\n\r\n");

    $buf = '';
    while (true) {
        $s = fread($sock,1024);
        if (!isset($s[0])) {
            break;
        }
        $buf .= $s;
    }
    $meta=stream_get_meta_data($sock);
    var_dump("end",$meta,$sock);
}

string(5) "start"
array(7) {
  ["stream_type"]=>
  string(14) "tcp_socket/ssl"
  ["mode"]=>
  string(2) "r+"
  ["unread_bytes"]=>
  int(0)
  ["seekable"]=>
  bool(false)
  ["timed_out"]=>
  bool(false)
  ["blocked"]=>
  bool(true)
  ["eof"]=>
  bool(false)
}
string(3) "end"
array(7) {
  ["stream_type"]=>
  string(14) "tcp_socket/ssl"
  ["mode"]=>
  string(2) "r+"
  ["unread_bytes"]=>
  int(0)
  ["seekable"]=>
  bool(false)
  ["timed_out"]=>
  bool(false)
  ["blocked"]=>
  bool(true)
  ["eof"]=>
  bool(true)
}
resource(175) of type (stream)