public function cancelOperation()
    {
        printf("Cancelling...\n");
        $this->_cancelled = true;
        posix_kill($this->_pid, SIGKILL);
        pcntl_signal_dispatch();
    }
public function cancelOperation()
    {
        printf("Cancelling...\n");
        $this->_cancelled = true;
        posix_kill($this->_pid, SIGKILL);
        pcntl_signal_dispatch();
    }
public function cancelOperation ( ) { printf ( "Cancelling...\n" ) ; $ this -> _cancelled = true ; posix_kill ( $ this -> _pid , SIGKILL ) ; pcntl_signal_dispatch ( ) ; }
While a child process is running, terminate it immediately.
While a child process is running terminate it immediately .