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发信人: GyeaonWoo (柏林恋人), 信区: Linux
标 题: Linus's Linux--kernel/tty_io.c
发信站: 荔园晨风BBS站 (Mon Aug 25 20:37:55 2003), 站内信件
/*
* 'tty_io.c' gives an orthogonal feeling to tty's, be they consoles
* or rs-channels. It also implements echoing, cooked mode etc (well,
* not currently, but ...)
*/
#include <ctype.h>
#include <errno.h>
#include <signal.h>
#define ALRMMASK (1<<(SIGALRM-1))
#include <linux/sched.h>
#include <linux/tty.h>
#include <asm/segment.h>
#include <asm/system.h>
#define _L_FLAG(tty,f) ((tty)->termios.c_lflag & f)
#define _I_FLAG(tty,f) ((tty)->termios.c_iflag & f)
#define _O_FLAG(tty,f) ((tty)->termios.c_oflag & f)
#define L_CANON(tty) _L_FLAG((tty),ICANON)
#define L_ISIG(tty) _L_FLAG((tty),ISIG)
#define L_ECHO(tty) _L_FLAG((tty),ECHO)
#define L_ECHOE(tty) _L_FLAG((tty),ECHOE)
#define L_ECHOK(tty) _L_FLAG((tty),ECHOK)
#define L_ECHOCTL(tty) _L_FLAG((tty),ECHOCTL)
#define L_ECHOKE(tty) _L_FLAG((tty),ECHOKE)
#define I_UCLC(tty) _I_FLAG((tty),IUCLC)
#define I_NLCR(tty) _I_FLAG((tty),INLCR)
#define I_CRNL(tty) _I_FLAG((tty),ICRNL)
#define I_NOCR(tty) _I_FLAG((tty),IGNCR)
#define O_POST(tty) _O_FLAG((tty),OPOST)
#define O_NLCR(tty) _O_FLAG((tty),ONLCR)
#define O_CRNL(tty) _O_FLAG((tty),OCRNL)
#define O_NLRET(tty) _O_FLAG((tty),ONLRET)
#define O_LCUC(tty) _O_FLAG((tty),OLCUC)
struct tty_struct tty_table[] = {
{
{0,
OPOST|ONLCR, /* change outgoing NL to CRNL */
0,
ICANON | ECHO | ECHOCTL | ECHOKE,
0, /* console termio */
INIT_C_CC},
0, /* initial pgrp */
0, /* initial stopped */
con_write,
{0,0,0,0,""}, /* console read-queue */
{0,0,0,0,""}, /* console write-queue */
{0,0,0,0,""} /* console secondary queue */
},{
{0, /*IGNCR*/
OPOST | ONLRET, /* change outgoing NL to CR */
B2400 | CS8,
0,
0,
INIT_C_CC},
0,
0,
rs_write,
{0x3f8,0,0,0,""}, /* rs 1 */
{0x3f8,0,0,0,""},
{0,0,0,0,""}
},{
{0, /*IGNCR*/
OPOST | ONLRET, /* change outgoing NL to CR */
B2400 | CS8,
0,
0,
INIT_C_CC},
0,
0,
rs_write,
{0x2f8,0,0,0,""}, /* rs 2 */
{0x2f8,0,0,0,""},
{0,0,0,0,""}
}
};
/*
* these are the tables used by the machine code handlers.
* you can implement pseudo-tty's or something by changing
* them. Currently not done.
*/
struct tty_queue * table_list[]={
&tty_table[0].read_q, &tty_table[0].write_q,
&tty_table[1].read_q, &tty_table[1].write_q,
&tty_table[2].read_q, &tty_table[2].write_q
};
void tty_init(void)
{
rs_init();
con_init();
}
void tty_intr(struct tty_struct * tty, int signal)
{
int i;
if (tty->pgrp <= 0)
return;
for (i=0;i<NR_TASKS;i++)
if (task[i] && task[i]->pgrp==tty->pgrp)
task[i]->signal |= 1<<(signal-1);
}
static void sleep_if_empty(struct tty_queue * queue)
{
cli();
while (!current->signal && EMPTY(*queue))
interruptible_sleep_on(&queue->proc_list);
sti();
}
static void sleep_if_full(struct tty_queue * queue)
{
if (!FULL(*queue))
return;
cli();
while (!current->signal && LEFT(*queue)<128)
interruptible_sleep_on(&queue->proc_list);
sti();
}
void copy_to_cooked(struct tty_struct * tty)
{
signed char c;
while (!EMPTY(tty->read_q) && !FULL(tty->secondary)) {
GETCH(tty->read_q,c);
if (c==13)
if (I_CRNL(tty))
c=10;
else if (I_NOCR(tty))
continue;
else ;
else if (c==10 && I_NLCR(tty))
c=13;
if (I_UCLC(tty))
c=tolower(c);
if (L_CANON(tty)) {
if (c==ERASE_CHAR(tty)) {
if (EMPTY(tty->secondary) ||
(c=LAST(tty->secondary))==10 ||
c==EOF_CHAR(tty))
continue;
if (L_ECHO(tty)) {
if (c<32)
PUTCH(127,tty->write_q);
PUTCH(127,tty->write_q);
tty->write(tty);
}
DEC(tty->secondary.head);
continue;
}
if (c==STOP_CHAR(tty)) {
tty->stopped=1;
continue;
}
if (c==START_CHAR(tty)) {
tty->stopped=0;
continue;
}
}
if (!L_ISIG(tty)) {
if (c==INTR_CHAR(tty)) {
tty_intr(tty,SIGINT);
continue;
}
}
if (c==10 || c==EOF_CHAR(tty))
tty->secondary.data++;
if (L_ECHO(tty)) {
if (c==10) {
PUTCH(10,tty->write_q);
PUTCH(13,tty->write_q);
} else if (c<32) {
if (L_ECHOCTL(tty)) {
PUTCH('^',tty->write_q);
PUTCH(c+64,tty->write_q);
}
} else
PUTCH(c,tty->write_q);
tty->write(tty);
}
PUTCH(c,tty->secondary);
}
wake_up(&tty->secondary.proc_list);
}
int tty_read(unsigned channel, char * buf, int nr)
{
struct tty_struct * tty;
char c, * b=buf;
int minimum,time,flag=0;
long oldalarm;
if (channel>2 || nr<0) return -1;
tty = &tty_table[channel];
oldalarm = current->alarm;
time = (unsigned) 10*tty->termios.c_cc[VTIME];
minimum = (unsigned) tty->termios.c_cc[VMIN];
if (time && !minimum) {
minimum=1;
if (flag=(!oldalarm || time+jiffies<oldalarm))
current->alarm = time+jiffies;
}
if (minimum>nr)
minimum=nr;
while (nr>0) {
if (flag && (current->signal & ALRMMASK)) {
current->signal &= ~ALRMMASK;
break;
}
if (current->signal)
break;
if (EMPTY(tty->secondary) || (L_CANON(tty) &&
!tty->secondary.data && LEFT(tty->secondary)>20)) {
sleep_if_empty(&tty->secondary);
continue;
}
do {
GETCH(tty->secondary,c);
if (c==EOF_CHAR(tty) || c==10)
tty->secondary.data--;
if (c==EOF_CHAR(tty) && L_CANON(tty))
return (b-buf);
else {
put_fs_byte(c,b++);
if (!--nr)
break;
}
} while (nr>0 && !EMPTY(tty->secondary));
if (time && !L_CANON(tty))
if (flag=(!oldalarm || time+jiffies<oldalarm))
current->alarm = time+jiffies;
else
current->alarm = oldalarm;
if (L_CANON(tty)) {
if (b-buf)
break;
} else if (b-buf >= minimum)
break;
}
current->alarm = oldalarm;
if (current->signal && !(b-buf))
return -EINTR;
return (b-buf);
}
int tty_write(unsigned channel, char * buf, int nr)
{
static cr_flag=0;
struct tty_struct * tty;
char c, *b=buf;
if (channel>2 || nr<0) return -1;
tty = channel + tty_table;
while (nr>0) {
sleep_if_full(&tty->write_q);
if (current->signal)
break;
while (nr>0 && !FULL(tty->write_q)) {
c=get_fs_byte(b);
if (O_POST(tty)) {
if (c=='\r' && O_CRNL(tty))
c='\n';
else if (c=='\n' && O_NLRET(tty))
c='\r';
if (c=='\n' && !cr_flag && O_NLCR(tty)) {
cr_flag = 1;
PUTCH(13,tty->write_q);
continue;
}
if (O_LCUC(tty))
c=toupper(c);
}
b++; nr--;
cr_flag = 0;
PUTCH(c,tty->write_q);
}
tty->write(tty);
if (nr>0)
schedule();
}
return (b-buf);
}
/*
* Jeh, sometimes I really like the 386.
* This routine is called from an interrupt,
* and there should be absolutely no problem
* with sleeping even in an interrupt (I hope).
* Of course, if somebody proves me wrong, I'll
* hate intel for all time :-). We'll have to
* be careful and see to reinstating the interrupt
* chips before calling this, though.
*/
void do_tty_interrupt(int tty)
{
copy_to_cooked(tty_table+tty);
}
--
暧昧中透出薄雾的晨花 无意间岁月发出的嫩芽
浅笑里波光闪动的艳影 惬意后醉了眉眼的旧话
旧梦中锋利的剑与白马 传说里等情人白了头发
追忆前寒窗明月的红腊 多年后流水洗尽的铅华桃李春风一杯酒 江湖夜雨十年灯紫薇雨中?
※ 来源:·荔园晨风BBS站 bbs.szu.edu.cn·[FROM: 192.168.35.5]
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