lib/Mutex.php
public function lock()
    {
        if ($this->fp === null) {
            $this->fp = fopen($this->file, 'r');
        }

        return flock($this->fp, LOCK_EX);
    }
public function lock()
    {
        if ($this->fp === null) {
            $this->fp = fopen($this->file, 'r');
        }

        return flock($this->fp, LOCK_EX);
    }
public function lock ( ) { if ( $ this -> fp === null ) { $ this -> fp = fopen ( $ this -> file , 'r' ) ; } return flock ( $ this -> fp , LOCK_EX ) ; }
Aquire the mutex

@return  boolean
Aquire the mutex