freebsd-skq/sys/kern/tty_subr.c
dg 90ed031776 Completed version of my clist management code. Requires hooks in tty.c
for adding and removing cblocks from the cfreelist queue (to give them
back to malloc). I'll add those tomorrow.
1994-05-27 12:28:05 +00:00

566 lines
12 KiB
C

/*
* Copyright (C) 1994, David Greenman. This software may be used, modified,
* copied, distributed, and sold, in both source and binary form provided
* that the above copyright and these terms are retained. Under no
* circumstances is the author responsible for the proper functioning
* of this software, nor does the author assume any responsibility
* for damages incurred with its use.
*
*/
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/ioctl.h>
#include <sys/tty.h>
#include <sys/clist.h>
#include <sys/malloc.h>
struct cblock *cfreelist = 0;
int cfreecount = 0;
#ifndef INITIAL_CBLOCKS
#define INITIAL_CBLOCKS 50
#endif
void cblock_alloc_cblocks __P((int));
#define MBUF_DIAG
#ifdef MBUF_DIAG
void
print_nblocks()
{
printf("There are currently %d bytes in cblocks\n", cfreecount);
}
#endif
/*
* Called from init_main.c
*/
void
clist_init()
{
/*
* Allocate an initial base set of cblocks as a 'slush'.
* We allocate more with each ttyopen().
*/
cblock_alloc_cblocks(INITIAL_CBLOCKS);
return;
}
/*
* Remove a cblock from the cfreelist queue and return a pointer
* to it.
*/
static inline struct cblock *
cblock_alloc()
{
struct cblock *cblockp;
cblockp = cfreelist;
if (!cblockp) {
/* XXX should syslog a message that we're out! */
return (0);
}
cfreelist = cblockp->c_next;
cblockp->c_next = NULL;
cfreecount -= CBSIZE;
return (cblockp);
}
/*
* Add a cblock to the cfreelist queue.
*/
static inline void
cblock_free(cblockp)
struct cblock *cblockp;
{
cblockp->c_next = cfreelist;
cfreelist = cblockp;
cfreecount += CBSIZE;
return;
}
/*
* Allocate some cblocks for the cfreelist queue.
*/
void
cblock_alloc_cblocks(number)
int number;
{
int i;
struct cblock *tmp;
for (i = 0; i < number; ++i) {
tmp = malloc(sizeof(struct cblock), M_TTYS, M_NOWAIT);
if (!tmp)
panic("clist_init: could not allocate cblock");
bzero((char *)tmp, sizeof(struct cblock));
cblock_free(tmp);
}
return;
}
/*
* Free some cblocks from the cfreelist queue back to the
* system malloc pool.
*/
void
cblock_free_cblocks(number)
int number;
{
int i;
struct cblock *tmp;
for (i = 0; i < number; ++i) {
tmp = cblock_alloc();
free(tmp, M_TTYS);
}
}
/*
* Get a character from the head of a clist.
*/
int
getc(clistp)
struct clist *clistp;
{
int chr = -1;
int s;
struct cblock *cblockp;
s = spltty();
/* If there are characters in the list, get one */
if (clistp->c_cc) {
cblockp = (struct cblock *)((long)clistp->c_cf & ~CROUND);
chr = (u_char)*clistp->c_cf;
/*
* If this char is quoted, set the flag.
*/
if (isset(cblockp->c_quote, clistp->c_cf - (char *)cblockp->c_info))
chr |= TTY_QUOTE;
/*
* Advance to next character.
*/
clistp->c_cf++;
clistp->c_cc--;
/*
* If we have advanced the 'first' character pointer
* past the end of this cblock, advance to the next one.
* If there are no more characters, set the first and
* last pointers to NULL. In either case, free the
* current cblock.
*/
if ((clistp->c_cf >= (char *)(cblockp+1)) || (clistp->c_cc == 0)) {
if (clistp->c_cc > 0) {
clistp->c_cf = cblockp->c_next->c_info;
} else {
clistp->c_cf = clistp->c_cl = NULL;
}
cblock_free(cblockp);
}
}
splx(s);
return (chr);
}
/*
* Copy 'amount' of chars, beginning at head of clist 'clistp' to
* destination linear buffer 'dest'. Return number of characters
* actually copied.
*/
int
q_to_b(clistp, dest, amount)
struct clist *clistp;
char *dest;
int amount;
{
struct cblock *cblockp;
struct cblock *cblockn;
char *dest_orig = dest;
int numc;
int s;
s = spltty();
while (clistp && amount && (clistp->c_cc > 0)) {
cblockp = (struct cblock *)((long)clistp->c_cf & ~CROUND);
cblockn = cblockp + 1; /* pointer arithmetic! */
numc = min(amount, (char *)cblockn - clistp->c_cf);
numc = min(numc, clistp->c_cc);
bcopy(clistp->c_cf, dest, numc);
amount -= numc;
clistp->c_cf += numc;
clistp->c_cc -= numc;
dest += numc;
/*
* If this cblock has been emptied, advance to the next
* one. If there are no more characters, set the first
* and last pointer to NULL. In either case, free the
* current cblock.
*/
if ((clistp->c_cf >= (char *)cblockn) || (clistp->c_cc == 0)) {
if (clistp->c_cc > 0) {
clistp->c_cf = cblockp->c_next->c_info;
} else {
clistp->c_cf = clistp->c_cl = NULL;
}
cblock_free(cblockp);
}
}
splx(s);
return (dest - dest_orig);
}
/*
* Flush 'amount' of chars, beginning at head of clist 'clistp'.
*/
void
ndflush(clistp, amount)
struct clist *clistp;
int amount;
{
struct cblock *cblockp;
struct cblock *cblockn;
int numc;
int s;
s = spltty();
while (amount && (clistp->c_cc > 0)) {
cblockp = (struct cblock *)((long)clistp->c_cf & ~CROUND);
cblockn = cblockp + 1; /* pointer arithmetic! */
numc = min(amount, (char *)cblockn - clistp->c_cf);
numc = min(numc, clistp->c_cc);
amount -= numc;
clistp->c_cf += numc;
clistp->c_cc -= numc;
/*
* If this cblock has been emptied, advance to the next
* one. If there are no more characters, set the first
* and last pointer to NULL. In either case, free the
* current cblock.
*/
if ((clistp->c_cf >= (char *)cblockn) || (clistp->c_cc == 0)) {
if (clistp->c_cc > 0) {
clistp->c_cf = cblockp->c_next->c_info;
} else {
clistp->c_cf = clistp->c_cl = NULL;
}
cblock_free(cblockp);
}
}
splx(s);
return;
}
/*
* Add a character to the end of a clist. Return -1 is no
* more clists, or 0 for success.
*/
int
putc(chr, clistp)
int chr;
struct clist *clistp;
{
struct cblock *cblockp, *bclockn;
int s;
s = spltty();
cblockp = (struct cblock *)((long)clistp->c_cl & ~CROUND);
if (clistp->c_cl == NULL) {
cblockp = cblock_alloc();
if (cblockp) {
clistp->c_cf = clistp->c_cl = cblockp->c_info;
clistp->c_cc = 0;
} else {
splx(s);
return (-1);
}
} else {
if (((long)clistp->c_cl & CROUND) == 0) {
struct cblock *prev = (cblockp - 1);
cblockp = cblock_alloc();
if (cblockp) {
prev->c_next = cblockp;
clistp->c_cl = cblockp->c_info;
} else {
splx(s);
return (-1);
}
}
}
/*
* If this character is quoted, set the quote bit, if not, clear it.
*/
if (chr & TTY_QUOTE)
setbit(cblockp->c_quote, clistp->c_cl - (char *)cblockp->c_info);
else
clrbit(cblockp->c_quote, clistp->c_cl - (char *)cblockp->c_info);
*clistp->c_cl++ = chr;
clistp->c_cc++;
splx(s);
return (0);
}
/*
* Copy data from linear buffer to clist chain. Return the
* number of characters not copied.
*/
int
b_to_q(src, amount, clistp)
char *src;
int amount;
struct clist *clistp;
{
struct cblock *cblockp, *bclockn;
char *firstbyte, *lastbyte;
u_char startmask, endmask;
int startbit, endbit, num_between, numc;
int s;
s = spltty();
/*
* If there are no cblocks assigned to this clist yet,
* then get one.
*/
if (clistp->c_cl == NULL) {
cblockp = cblock_alloc();
if (cblockp) {
clistp->c_cf = clistp->c_cl = cblockp->c_info;
clistp->c_cc = 0;
} else {
splx(s);
return (amount);
}
} else {
cblockp = (struct cblock *)((long)clistp->c_cl & ~CROUND);
}
while (amount) {
/*
* Get another cblock if needed.
*/
if (((long)clistp->c_cl & CROUND) == 0) {
struct cblock *prev = cblockp - 1;
cblockp = cblock_alloc();
if (cblockp) {
prev->c_next = cblockp;
clistp->c_cl = cblockp->c_info;
} else {
splx(s);
return (amount);
}
}
/*
* Copy a chunk of the linear buffer up to the end
* of this cblock.
*/
numc = min(amount, (char *)(cblockp + 1) - clistp->c_cl);
bcopy(src, clistp->c_cl, numc);
/*
* Clear quote bits. The following could probably be made into
* a seperate "bitzero()" routine, but why bother?
*/
startbit = clistp->c_cl - (char *)cblockp->c_info;
endbit = startbit + numc - 1;
firstbyte = (u_char *)cblockp->c_quote + (startbit / NBBY);
lastbyte = (u_char *)cblockp->c_quote + (endbit / NBBY);
/*
* Calculate mask of bits to preserve in first and
* last bytes.
*/
startmask = NBBY - (startbit % NBBY);
startmask = 0xff >> startmask;
endmask = (endbit % NBBY);
endmask = 0xff << (endmask + 1);
if (firstbyte != lastbyte) {
*firstbyte &= startmask;
*lastbyte &= endmask;
num_between = lastbyte - firstbyte - 1;
if (num_between)
bzero(firstbyte + 1, num_between);
} else {
*firstbyte &= (startmask | endmask);
}
/*
* ...and update pointer for the next chunk.
*/
src += numc;
clistp->c_cl += numc;
clistp->c_cc += numc;
amount -= numc;
/*
* If we go through the loop again, it's always
* for data in the next cblock, so by adding one (cblock),
* (which makes the pointer 1 beyond the end of this
* cblock) we prepare for the assignment of 'prev'
* above.
*/
cblockp += 1;
}
splx(s);
return (amount);
}
/*
* Get the next character in the clist. Store it at dst. Don't
* advance any clist pointers, but return a pointer to the next
* character position.
*/
char *
nextc(clistp, cp, dst)
struct clist *clistp;
char *cp;
int *dst;
{
struct cblock *cblockp;
++cp;
/*
* See if the next character is beyond the end of
* the clist.
*/
if (clistp->c_cc && (cp != clistp->c_cl)) {
/*
* If the next character is beyond the end of this
* cblock, advance to the next cblock.
*/
if (((long)cp & CROUND) == 0)
cp = ((struct cblock *)cp - 1)->c_next->c_info;
cblockp = (struct cblock *)((long)cp & ~CROUND);
/*
* Get the character. Set the quote flag if this character
* is quoted.
*/
*dst = (u_char)*cp | (isset(cblockp->c_quote, cp - (char *)cblockp->c_info) ? TTY_QUOTE : 0);
return (cp);
}
return (NULL);
}
/*
* "Unput" a character from a clist.
*/
int
unputc(clistp)
struct clist *clistp;
{
struct cblock *cblockp = 0, *cbp = 0;
int s;
int chr = -1;
s = spltty();
if (clistp->c_cc) {
--clistp->c_cc;
--clistp->c_cl;
chr = (u_char)*clistp->c_cl;
cblockp = (struct cblock *)((long)clistp->c_cl & ~CROUND);
/*
* Set quote flag if this character was quoted.
*/
if (isset(cblockp->c_quote, (u_char *)clistp->c_cl - cblockp->c_info))
chr |= TTY_QUOTE;
/*
* If all of the characters have been unput in this
* cblock, then find the previous one and free this
* one.
*/
if (clistp->c_cc && (clistp->c_cl <= (char *)cblockp->c_info)) {
cbp = (struct cblock *)((long)clistp->c_cf & ~CROUND);
while (cbp->c_next != cblockp)
cbp = cbp->c_next;
/*
* When the previous cblock is at the end, the 'last'
* pointer always points (invalidly) one past.
*/
clistp->c_cl = (char *)(cbp+1);
cblock_free(cblockp);
cbp->c_next = NULL;
}
}
/*
* If there are no more characters on the list, then
* free the last cblock.
*/
if ((clistp->c_cc == 0) && clistp->c_cl) {
cblockp = (struct cblock *)((long)clistp->c_cl & ~CROUND);
cblock_free(cblockp);
clistp->c_cf = clistp->c_cl = NULL;
}
splx(s);
return (chr);
}
/*
* Move characters in source clist to destination clist,
* preserving quote bits.
*/
void
catq(src_clistp, dest_clistp)
struct clist *src_clistp, *dest_clistp;
{
int chr, s;
s = spltty();
/*
* If the destination clist is empty (has no cblocks atttached),
* then we simply assign the current clist to the destination.
*/
if (!dest_clistp->c_cf) {
dest_clistp->c_cf = src_clistp->c_cf;
dest_clistp->c_cl = src_clistp->c_cl;
src_clistp->c_cf = src_clistp->c_cl = NULL;
dest_clistp->c_cc = src_clistp->c_cc;
src_clistp->c_cc = 0;
splx(s);
return;
}
splx(s);
/*
* XXX This should probably be optimized to more than one
* character at a time.
*/
while ((chr = getc(src_clistp)) != -1)
putc(chr, dest_clistp);
return;
}