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# Copyright(c) 1986 Association of Universities for Research in Astronomy Inc.
include <config.h>
include <mach.h>
include "ki.h"
# KT_ZOPN -- Open a text device. We are called only if the device does not
# reside on the local node.
procedure kt_zopn (device, osfn, mode, chan)
int device # device driver code
char osfn[ARB] # packed os filename
int mode # access mode
int chan # receives assigned channel
pointer bd, bp
int server
int ki_connect(), ki_sendrcv(), ki_getchan(), kmalloc()
include "kichan.com"
include "kii.com"
begin
server = ki_connect (osfn)
p_arg[2] = mode
if (ki_sendrcv (server, device, TX_OPN) == ERR)
chan = ERR
else if (p_arg[1] == ERR)
chan = ERR
else if (kmalloc (bd, LEN_TXBDES, TY_STRUCT) == ERR)
chan = ERR
else {
chan = ki_getchan (server, p_arg[1])
k_bufp[chan] = NULL
# Init the text buffer and buffer descriptor. Text i/o over the
# KI is buffered, greatly reducing the number of packets sent back
# and forth between nodes and likewise increasing the bandwidth.
# Buffering at the KI layer is necessary because FIO buffers only
# one line of text at a time, leaving blocking and deblocking of
# text lines to the kernel.
k_bufp[chan] = bd
bp = B_BUFPTR(bd)
B_RP(bd) = bp
B_CI(bd) = 0
B_ITOP(bd) = bp
B_OTOP(bd) = bp
B_BUFTOP(bd) = bp + SZ_TXBUF
}
end
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