Thank you for your detailed explanations. I understood why your patch works without problem.
Best regards, Takashi Yano On Sun, 22 Mar 2015 10:37:37 +0100 Mats Erik Andersson <mats.anders...@gisladisker.se> wrote: > Dear Takashi Yano! > > Den 22 March 2015 klockan 14:32 skrev Takashi Yano detta: > > Thank you for your reply. > > > > With your patch, I have confirmed the problem has disappeared. > > > > However, I am a little bit concerned about calling pty_get_char(0) > > twice in the case of TIOCPKT_FLUSHWRITE or TIOCPKT_IOCTL. > > > > Is it intentional behaviour? > > A relevant observation. When acting on TIOCPKT_IOCTL the call sequence > > pty_get_char (0); > copy_termbuf (); /* Pty buffer is now emtied. */ > localstat (); > > discards the packet preamble, then copies payload and resets the > buffer. This will make sure that any following pty_get_char(0) > becomes a no-op as no data is left. The remark above was introduced > to the development head to record this observation, but I left it > out in my comment to the list as is has no effect on the program. > > The case of TIOCPKT_FLUSHWRITE is different, as only the network > buffer is touched, apart from the single pty_get_char(0). Now it > seems that your worry is justified. According to pty(7D) on Solaris > > When a pseudo-terminal is in packet mode, the controller > device will return data preceded by TIOCPKT_DATA (= 0), > or a single byte reflecting control status information. > > This means that TIOCPKT_FLUSHWRITE arrives isolated, so also in this > case the pty buffer is empty after the first pty_get_char(0) and the > second becomes a no-op again. However, even though the control byte > was flushed, is is still preserved in the variable 'c', so the > next test is still correct even if (TIOCPKT_FLUSHWRITE | TIOCPKT_STOP) > had been received. Neither of TIOCPKT_NOSTOP and TIOCPKT_STOP touches > the pty buffer, so no harmful side effect is possible. The code would > look better without this first pty_get_char(0), so I might remove it > for better understanding and quality. > > I thank you for your interest and care in this matter. > > Best regards, > Mats Erik Andersson -- Takashi Yano <takashi.y...@nifty.ne.jp>
