12bc45a8df
TTYHOG = 1024 bytes, 10 cblocks were reserved. This was thought to provide 10 * CBSIZE = 1080 bytes of buffering, but if the head pointer is at the end of a cblock, then it only provides 1 + 9 * CBSIZE = 973 bytes of buffering. This caused serious data loss for ptys because the flow control is deterministic and requires at least TTYHOG bytes of buffering. For ttys, if input flow control is used then there is usually enough slop in the high watermark to avoid problems, and if input flow control isn't used then a limit of 973 is not much different from a limit of 1024. Add prototypes. Continue cleaning up new init stuff.
668 lines
15 KiB
C
668 lines
15 KiB
C
/*
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* Copyright (C) 1994, David Greenman. This software may be used, modified,
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* copied, distributed, and sold, in both source and binary form provided
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* that the above copyright and these terms are retained. Under no
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* circumstances is the author responsible for the proper functioning
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* of this software, nor does the author assume any responsibility
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* for damages incurred with its use.
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*
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* $Id: tty_subr.c,v 1.13 1995/09/09 18:10:10 davidg Exp $
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*/
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/*
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* clist support routines
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*/
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#include <sys/param.h>
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#include <sys/kernel.h>
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#include <sys/systm.h>
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#include <sys/ioctl.h>
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#include <sys/tty.h>
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#include <sys/clist.h>
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#include <sys/malloc.h>
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static void clist_init __P((void *));
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SYSINIT(clist, SI_SUB_CLIST, SI_ORDER_FIRST, clist_init, NULL)
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struct cblock *cfreelist = 0;
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int cfreecount = 0;
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static int cslushcount;
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static int ctotcount;
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#ifndef INITIAL_CBLOCKS
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#define INITIAL_CBLOCKS 50
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#endif
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static struct cblock *cblock_alloc __P((void));
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static void cblock_alloc_cblocks __P((int number));
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static void cblock_free __P((struct cblock *cblockp));
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static void cblock_free_cblocks __P((int number));
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#define CBLOCK_DIAG
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#ifdef CBLOCK_DIAG
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static void cbstat __P((void));
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static void
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cbstat()
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{
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printf(
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"tot = %d (active = %d, free = %d (reserved = %d, slush = %d))\n",
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ctotcount * CBSIZE, ctotcount * CBSIZE - cfreecount, cfreecount,
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cfreecount - cslushcount * CBSIZE, cslushcount * CBSIZE);
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}
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#endif
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/*
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* Called from init_main.c
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*/
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/* ARGSUSED*/
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static void
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clist_init(dummy)
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void *dummy;
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{
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/*
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* Allocate an initial base set of cblocks as a 'slush'.
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* We allocate non-slush cblocks with each initial ttyopen() and
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* deallocate them with each ttyclose().
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* We should adjust the slush allocation. This can't be done in
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* the i/o routines because they are sometimes called from
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* interrupt handlers when it may be unsafe to call malloc().
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*/
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cblock_alloc_cblocks(cslushcount = INITIAL_CBLOCKS);
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}
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/*
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* Remove a cblock from the cfreelist queue and return a pointer
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* to it.
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*/
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static inline struct cblock *
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cblock_alloc()
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{
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struct cblock *cblockp;
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cblockp = cfreelist;
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if (cblockp == NULL)
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panic("clist reservation botch");
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cfreelist = cblockp->c_next;
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cblockp->c_next = NULL;
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cfreecount -= CBSIZE;
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return (cblockp);
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}
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/*
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* Add a cblock to the cfreelist queue.
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*/
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static inline void
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cblock_free(cblockp)
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struct cblock *cblockp;
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{
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if (isset(cblockp->c_quote, CBQSIZE * NBBY - 1))
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bzero(cblockp->c_quote, sizeof cblockp->c_quote);
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cblockp->c_next = cfreelist;
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cfreelist = cblockp;
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cfreecount += CBSIZE;
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}
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/*
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* Allocate some cblocks for the cfreelist queue.
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*/
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static void
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cblock_alloc_cblocks(number)
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int number;
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{
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int i;
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struct cblock *cbp;
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for (i = 0; i < number; ++i) {
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cbp = malloc(sizeof *cbp, M_TTYS, M_WAITOK);
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/*
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* Freed cblocks have zero quotes and garbage elsewhere.
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* Set the may-have-quote bit to force zeroing the quotes.
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*/
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setbit(cbp->c_quote, CBQSIZE * NBBY - 1);
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cblock_free(cbp);
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}
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ctotcount += number;
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}
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/*
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* Set the cblock allocation policy for a a clist.
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* Must be called in process context at spltty().
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*/
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void
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clist_alloc_cblocks(clistp, ccmax, ccreserved)
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struct clist *clistp;
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int ccmax;
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int ccreserved;
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{
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int dcbr;
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/*
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* Allow for wasted space at the head.
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*/
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if (ccmax != 0)
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ccmax += CBSIZE - 1;
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if (ccreserved != 0)
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ccreserved += CBSIZE - 1;
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clistp->c_cbmax = roundup(ccmax, CBSIZE) / CBSIZE;
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dcbr = roundup(ccreserved, CBSIZE) / CBSIZE - clistp->c_cbreserved;
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if (dcbr >= 0)
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cblock_alloc_cblocks(dcbr);
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else {
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if (clistp->c_cbreserved + dcbr < clistp->c_cbcount)
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dcbr = clistp->c_cbcount - clistp->c_cbreserved;
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cblock_free_cblocks(-dcbr);
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}
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clistp->c_cbreserved += dcbr;
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}
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/*
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* Free some cblocks from the cfreelist queue back to the
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* system malloc pool.
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*/
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static void
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cblock_free_cblocks(number)
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int number;
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{
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int i;
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for (i = 0; i < number; ++i)
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free(cblock_alloc(), M_TTYS);
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ctotcount -= number;
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}
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/*
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* Free the cblocks reserved for a clist.
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* Must be called at spltty().
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*/
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void
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clist_free_cblocks(clistp)
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struct clist *clistp;
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{
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if (clistp->c_cbcount != 0)
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panic("freeing active clist cblocks");
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cblock_free_cblocks(clistp->c_cbreserved);
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clistp->c_cbmax = 0;
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clistp->c_cbreserved = 0;
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}
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/*
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* Get a character from the head of a clist.
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*/
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int
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getc(clistp)
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struct clist *clistp;
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{
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int chr = -1;
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int s;
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struct cblock *cblockp;
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s = spltty();
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/* If there are characters in the list, get one */
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if (clistp->c_cc) {
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cblockp = (struct cblock *)((long)clistp->c_cf & ~CROUND);
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chr = (u_char)*clistp->c_cf;
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/*
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* If this char is quoted, set the flag.
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*/
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if (isset(cblockp->c_quote, clistp->c_cf - (char *)cblockp->c_info))
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chr |= TTY_QUOTE;
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/*
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* Advance to next character.
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*/
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clistp->c_cf++;
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clistp->c_cc--;
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/*
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* If we have advanced the 'first' character pointer
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* past the end of this cblock, advance to the next one.
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* If there are no more characters, set the first and
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* last pointers to NULL. In either case, free the
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* current cblock.
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*/
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if ((clistp->c_cf >= (char *)(cblockp+1)) || (clistp->c_cc == 0)) {
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if (clistp->c_cc > 0) {
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clistp->c_cf = cblockp->c_next->c_info;
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} else {
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clistp->c_cf = clistp->c_cl = NULL;
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}
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cblock_free(cblockp);
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if (--clistp->c_cbcount >= clistp->c_cbreserved)
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++cslushcount;
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}
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}
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splx(s);
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return (chr);
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}
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/*
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* Copy 'amount' of chars, beginning at head of clist 'clistp' to
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* destination linear buffer 'dest'. Return number of characters
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* actually copied.
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*/
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int
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q_to_b(clistp, dest, amount)
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struct clist *clistp;
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char *dest;
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int amount;
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{
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struct cblock *cblockp;
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struct cblock *cblockn;
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char *dest_orig = dest;
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int numc;
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int s;
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s = spltty();
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while (clistp && amount && (clistp->c_cc > 0)) {
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cblockp = (struct cblock *)((long)clistp->c_cf & ~CROUND);
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cblockn = cblockp + 1; /* pointer arithmetic! */
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numc = min(amount, (char *)cblockn - clistp->c_cf);
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numc = min(numc, clistp->c_cc);
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bcopy(clistp->c_cf, dest, numc);
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amount -= numc;
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clistp->c_cf += numc;
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clistp->c_cc -= numc;
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dest += numc;
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/*
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* If this cblock has been emptied, advance to the next
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* one. If there are no more characters, set the first
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* and last pointer to NULL. In either case, free the
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* current cblock.
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*/
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if ((clistp->c_cf >= (char *)cblockn) || (clistp->c_cc == 0)) {
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if (clistp->c_cc > 0) {
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clistp->c_cf = cblockp->c_next->c_info;
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} else {
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clistp->c_cf = clistp->c_cl = NULL;
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}
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cblock_free(cblockp);
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if (--clistp->c_cbcount >= clistp->c_cbreserved)
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++cslushcount;
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}
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}
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splx(s);
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return (dest - dest_orig);
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}
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/*
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* Flush 'amount' of chars, beginning at head of clist 'clistp'.
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*/
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void
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ndflush(clistp, amount)
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struct clist *clistp;
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int amount;
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{
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struct cblock *cblockp;
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struct cblock *cblockn;
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int numc;
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int s;
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s = spltty();
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while (amount && (clistp->c_cc > 0)) {
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cblockp = (struct cblock *)((long)clistp->c_cf & ~CROUND);
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cblockn = cblockp + 1; /* pointer arithmetic! */
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numc = min(amount, (char *)cblockn - clistp->c_cf);
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numc = min(numc, clistp->c_cc);
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amount -= numc;
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clistp->c_cf += numc;
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clistp->c_cc -= numc;
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/*
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* If this cblock has been emptied, advance to the next
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* one. If there are no more characters, set the first
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* and last pointer to NULL. In either case, free the
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* current cblock.
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*/
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if ((clistp->c_cf >= (char *)cblockn) || (clistp->c_cc == 0)) {
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if (clistp->c_cc > 0) {
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clistp->c_cf = cblockp->c_next->c_info;
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} else {
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clistp->c_cf = clistp->c_cl = NULL;
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}
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cblock_free(cblockp);
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if (--clistp->c_cbcount >= clistp->c_cbreserved)
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++cslushcount;
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}
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}
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splx(s);
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}
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/*
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* Add a character to the end of a clist. Return -1 is no
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* more clists, or 0 for success.
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*/
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int
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putc(chr, clistp)
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int chr;
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struct clist *clistp;
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{
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struct cblock *cblockp;
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int s;
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s = spltty();
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if (clistp->c_cl == NULL) {
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if (clistp->c_cbreserved < 1)
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panic("putc to a clist with no reserved cblocks");
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cblockp = cblock_alloc();
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clistp->c_cbcount = 1;
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clistp->c_cf = clistp->c_cl = cblockp->c_info;
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clistp->c_cc = 0;
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} else {
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cblockp = (struct cblock *)((long)clistp->c_cl & ~CROUND);
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if (((long)clistp->c_cl & CROUND) == 0) {
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struct cblock *prev = (cblockp - 1);
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if (clistp->c_cbcount >= clistp->c_cbreserved) {
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if (clistp->c_cbcount >= clistp->c_cbmax
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|| cslushcount <= 0) {
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splx(s);
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return (-1);
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}
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--cslushcount;
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}
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cblockp = cblock_alloc();
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clistp->c_cbcount++;
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prev->c_next = cblockp;
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clistp->c_cl = cblockp->c_info;
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}
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}
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/*
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* If this character is quoted, set the quote bit, if not, clear it.
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*/
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if (chr & TTY_QUOTE) {
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setbit(cblockp->c_quote, clistp->c_cl - (char *)cblockp->c_info);
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/*
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* Use one of the spare quote bits to record that something
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* may be quoted.
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*/
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setbit(cblockp->c_quote, CBQSIZE * NBBY - 1);
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} else
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clrbit(cblockp->c_quote, clistp->c_cl - (char *)cblockp->c_info);
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*clistp->c_cl++ = chr;
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clistp->c_cc++;
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splx(s);
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return (0);
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}
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/*
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* Copy data from linear buffer to clist chain. Return the
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* number of characters not copied.
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*/
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int
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b_to_q(src, amount, clistp)
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char *src;
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int amount;
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struct clist *clistp;
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{
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struct cblock *cblockp;
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char *firstbyte, *lastbyte;
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u_char startmask, endmask;
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int startbit, endbit, num_between, numc;
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int s;
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/*
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* Avoid allocating an initial cblock and then not using it.
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* c_cc == 0 must imply c_cbount == 0.
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*/
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if (amount <= 0)
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return (amount);
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s = spltty();
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/*
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* If there are no cblocks assigned to this clist yet,
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* then get one.
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*/
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if (clistp->c_cl == NULL) {
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if (clistp->c_cbreserved < 1)
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panic("b_to_q to a clist with no reserved cblocks");
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cblockp = cblock_alloc();
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clistp->c_cbcount = 1;
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clistp->c_cf = clistp->c_cl = cblockp->c_info;
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clistp->c_cc = 0;
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} else {
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cblockp = (struct cblock *)((long)clistp->c_cl & ~CROUND);
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}
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while (amount) {
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/*
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* Get another cblock if needed.
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*/
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if (((long)clistp->c_cl & CROUND) == 0) {
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struct cblock *prev = cblockp - 1;
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if (clistp->c_cbcount >= clistp->c_cbreserved) {
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if (clistp->c_cbcount >= clistp->c_cbmax
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|| cslushcount <= 0) {
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splx(s);
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return (amount);
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}
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--cslushcount;
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}
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cblockp = cblock_alloc();
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clistp->c_cbcount++;
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prev->c_next = cblockp;
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clistp->c_cl = cblockp->c_info;
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}
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/*
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* Copy a chunk of the linear buffer up to the end
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* of this cblock.
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*/
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numc = min(amount, (char *)(cblockp + 1) - clistp->c_cl);
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bcopy(src, clistp->c_cl, numc);
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/*
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* Clear quote bits if they aren't known to be clear.
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* The following could probably be made into a seperate
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* "bitzero()" routine, but why bother?
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*/
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if (isset(cblockp->c_quote, CBQSIZE * NBBY - 1)) {
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startbit = clistp->c_cl - (char *)cblockp->c_info;
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endbit = startbit + numc - 1;
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firstbyte = (u_char *)cblockp->c_quote + (startbit / NBBY);
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lastbyte = (u_char *)cblockp->c_quote + (endbit / NBBY);
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/*
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* Calculate mask of bits to preserve in first and
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* last bytes.
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*/
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startmask = NBBY - (startbit % NBBY);
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startmask = 0xff >> startmask;
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endmask = (endbit % NBBY);
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endmask = 0xff << (endmask + 1);
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if (firstbyte != lastbyte) {
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*firstbyte &= startmask;
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*lastbyte &= endmask;
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num_between = lastbyte - firstbyte - 1;
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if (num_between)
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bzero(firstbyte + 1, num_between);
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} else {
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*firstbyte &= (startmask | endmask);
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}
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}
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/*
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* ...and update pointer for the next chunk.
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*/
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src += numc;
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clistp->c_cl += numc;
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clistp->c_cc += numc;
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amount -= numc;
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/*
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* If we go through the loop again, it's always
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* for data in the next cblock, so by adding one (cblock),
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* (which makes the pointer 1 beyond the end of this
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* cblock) we prepare for the assignment of 'prev'
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* above.
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*/
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cblockp += 1;
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}
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splx(s);
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return (amount);
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}
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/*
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* 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);
|
|
if (--clistp->c_cbcount >= clistp->c_cbreserved)
|
|
++cslushcount;
|
|
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);
|
|
if (--clistp->c_cbcount >= clistp->c_cbreserved)
|
|
++cslushcount;
|
|
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),
|
|
* and there are no possible complications with the resource counters,
|
|
* then we simply assign the current clist to the destination.
|
|
*/
|
|
if (!dest_clistp->c_cf
|
|
&& src_clistp->c_cbcount <= src_clistp->c_cbmax
|
|
&& src_clistp->c_cbcount <= dest_clistp->c_cbmax) {
|
|
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;
|
|
dest_clistp->c_cbcount = src_clistp->c_cbcount;
|
|
src_clistp->c_cbcount = 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);
|
|
}
|