code:flushtty - ikarishinjieva/unixV6-code-analyze-chs GitHub Wiki

8250 /* flush all TTY queues

8251 */

8252 flushtty(atp)

8253 struct tty *atp;

8254 {

8255 register struct tty *tp;

8256 register int sps;

8257 tp = atp;

8258 while (getc(&tp->t_canq) >= 0);

清空非原始输入队列

8259 while (getc(&tp->t_outq) >= 0);

清空输出队列

8260 wakeup(&tp->t_rawq);

8261 wakeup(&tp->t_outq);

唤醒等待以下队列的进程

原始输入队列

输出队列

8262 sps = PS->integ;

8263 spl5();

8264 while (getc(&tp->t_rawq) >= 0);

8265 tp->t_delct = 0;

8266 PS->integ = sps;

清空原始输入队列

清零定界符数

中断等级提升到5，为了防止清空过程中有新的字符进入

8267 }

8268 /* ------------------------- */