php 文件鎖實現

define("LOCK_FILE", "./1.txt");

lockqueue();
function lockqueue(){
    if(defined('LOCK_FILE')){
        $lock = file_get_contents(LOCK_FILE);
        switch ($lock){
            case '1':
                file_put_contents(LOCK_FILE, '2');
                die("please waitinig queue...\n");
                break;
            case '2':
                file_put_contents(LOCK_FILE, '3');
                die("please waitinig queue...\n");
                break;
            case '3':
                file_put_contents(LOCK_FILE, '4');
                die("please waitinig queue...\n");
                break;
            case '4':
                file_put_contents(LOCK_FILE, '5');
                die("please waitinig queue...\n");
                break;
            case '5':
                file_put_contents(LOCK_FILE, '0');
                die("please waitinig queue...\n");
                break;
            default:
                 file_put_contents(LOCK_FILE, '100');//上鎖
        }
    }
}