[Boost-users] Boost-users] [asio]about reactor_op_queue dead loop

I call boost::asio::async_write, finally it call "bool enqueue_operation(Descriptor descriptor, Operation operation)" In this function , there is code as flow: while (current_op->next_) current_op = current_op->next_; My process execute it for ever. Using gdb to attach the prcocess, I find : 68 while (current_op->next_) (gdb) p current_op $8 = (class boost::asio::detail::reactor_op_queue<int>::op_base *) 0x93381c8 (gdb) p current_op->next_ $9 = (class boost::asio::detail::reactor_op_queue<int>::op_base *) 0x93381c8 current_op and current_op->next_ is the same address. how did it come true? I have no any clue. Anyone can offer some suggestion?