请写一段PHP代码，确保多个进程同时写入同一个文件成功

 1 function writeData($path, $mode, $data){ 
 2                 $fp          = fopen($path, $mode); 
 3                 $retries     = 0;
 4                 $max_retries = 100; 
 5                 do {
 6                     if ($retries > 0) {
 7                         usleep(rand(1, 10000));
 8                     }
 9                     $retries += 1;
10                 }while (!flock($fp, LOCK_EX) and $retries <= $max_retries);
11 
12                 if ($retries == $max_retries) {
13                     return false;
14                 }
15                 
16                 fwrite($fp, "$data\n");
17                 flock($fp, LOCK_UN);
18                 fclose($fp); 
19                 return true; 
20         }