system@asuvax.UUCP (Marc Lesure) (10/29/85)
WMS 1.7b NEWSLETTER #3, 10/28/85 (MAJOR UPDATES) [net.sources]
This is a supplemental newsletter for users of the ASU Window Management System.
These updates affect code performance and should be tended to ASAP.
The previous method of polled I/O is replaced by a synchronous interrupt
driven scheme (based on select(2)). This results in improved performance
due to significantly reduced system loading.
Major Updates follow:
======= File: release/makefile
======= Change the line:
v = 1.7b # version
======= to:
v = 1.7c # version
======= File: release/source/msh/msh.c
======= Near the top of the file, change:
#include <sys/timeb.h>
======= to:
#include <sys/time.h>
======= After the line:
static bool C_result;
======= add:
static short delta_shell = 0;
======= Replace the entire procedure slave_driver() by:
public slave_driver()
/* Poll slave 'slave_index'. Send any and all input thus received to the
* remote window manager for output to its window.
*/
{
int result;
reg slave_t *sp, *tsp;
char chb[AMAXCBUF]; reg char *chbp = chb;
unsigned int m_mask; /* current master mask */
unsigned int s_mask; /* current slave mask */
static unsigned int sav_s_mask = 0; /* static mask */
static unsigned int pre_s_mask = 0; /* previous mask */
static int skip = AMAXSLAVES << 4; /* ad hoc */
/* skip select @ init, when activity continuous & every delta_shell */
m_mask = 1; /* master input fd 0 */
if (pre_s_mask == 0) { /* if no more slave leftovers */
if (delta_shell) { short i; /* recompute static mask */
skip = (delta_shell--) << 4; /* ad hoc */
sav_s_mask = 0;
for (i = 0; i < MAXSLAVES; i++)
if (slave[i].pid != NIL)
sav_s_mask |= (1 << slave[i].pty.f);
}
s_mask = sav_s_mask;
if (skip == 0) {
int mask;
struct timeval tout;
long t = (long) time(0);
mask = m_mask|s_mask;
tout.tv_sec = (long) 10000000;
tout.tv_usec = (long) 0;
/* block until master input or slave output ready */
select(20, &mask, 0, 0, &tout); /* 20 => OPEN_MAX */
m_mask = 01 & mask;
s_mask = ((~0) << 1) & mask;
if ((long) time(0) - t < 2) skip = AMAXSLAVES << 4;
} else skip--;
pre_s_mask = s_mask;
}
if (m_mask == 1) master_driver(); /* even if leftovers */
if (pre_s_mask == 0) return; /* no slave to do this time */
/* find next slave */
while (((1 << slave[slave_index = ((++slave_index) % MAXSLAVES)].pty.f)
& pre_s_mask) == 0) ;
if ((sp = &slave[slave_index])->pid == NIL) { /* due to do_DS */
pre_s_mask = 0;
return;
}
pre_s_mask &= (~(1 << sp->pty.f)); /* drop it from leftover set */
/* do only one slave per call => leftovers */
if ((result = get_slave(sp,chbp,MAXCBUF)) > 0) {
/* KLUDGE: If the slave has just been created,
* now is the time to tell it about TERM
*/
if (sp->rs_pending) {
/* for do_RS */
tsp = islave;
islave = sp;
sp->rs_pending = FALSE;
do_RS(sp->rs_tc);
islave = tsp;
}
/* here is the output fragment packet header */
goto_win(&(sp->label));
put_master(chbp,result);
}
} /* slave_driver */
======= Add to the beginning of procedures do_CU() and do_DS():
++delta_shell;
======= In function get_slave(), add:
++delta_shell;
======= just before the line:
len = (-1);
======= In procedure set_state(), change:
ioctl(f,TIOCGETD,&(ttyp->d));
======= to:
ioctl(f,TIOCSETD,&(ttyp->d));
======= File: release/mant/wms.t
======= After the lines:
This parameter does not apply to the current input shell when an echo is
pending.
======= add:
.PP
NOTE: The MAXNOPOLLS parameter has been rendered useless in versions 1.7c and
later due to the substitution of interrupt driven I/O for polled I/O.
======= File: release/public/termcap
======= Replace the entire "ansi" entry by:
0|ansi|ANSI|dec vt100 superset :\
:am:al=8\E[1L:\
:bc=2^H:\
:cd=50\E[J:ce=8\E[K:cl=50\E[H\E[2J:cm=15\E[%i%d;%dH:co#80:cr=5^M:\
:cs=15\E[%i%d;%dr:\
:dc=5\E[1P:dl=5\E[1M:dm=:do=8^J:\
:ed=:ei=:\
:ho=10\E[H:\
:ic=5\E[1@:im=:is=50\E[2J\E[H:\
:k0=\EOP:k1=\EOQ:k2=\EOR:k3=\EOS:k4=\EOT:\
:k5=\EOU:k6=\EOV:k7=\EOW:k8=\EOX:k9=\EOY:\
:kd=\EOB:ke=\E[?1l\E>:kl=\EOD:kr=\EOC:ks=\E[?1h\E=:ku=\EOA:\
:li#24:\
:nd=2\E[C:nl=8^J:\
:pt:\
:se=2\E[m:sf=10\ED:sg#0:so=2\E[7m:sr=10\EM:\
:ue=2\E[m:ug#0:us=2\E[4m:up=8\E[A:\
:ve=:vs=:\
:we=50\E[2J\E[1;24r\E[H:ws=50\E[2J\E[1;24r\E[H:
======= File: release/source/NOTES
======= Add to the end of the file the lines:
------------------------------------------------------------------------------
According to the select system call documentation, a call of the form:
select(nbits,&inmask,&outmask,&excmask,(struct timeval *) 0)
is supposed to block until something is ready. What really happens is that
the call returns immediately (without blocking). That is why the method
(tout.tv_sec = ...) was used (in slave_driver). This should, of course,
be intuitively obvious even to the casual observer off the street. :-(
======= End of Updates. Summary:
- Change version.
- Add code to make IO interrupt driven.
- Correct typo in setstate().
- Modify wms manual to account for I/O change.
- Patch "ansi" entry: cleanup & add more delay where experience has revealed
- delay timing problems with vi under certain circumstances.
- Add to source/NOTES.
- Thanks to Mario Wolczko et al (..!ukc!edcaad!mupsy!mucs!miw) for suggesting
- use of select system call.
George Nelan UUCP:
Engineering Research Center (ERC 207) ...{ucbvax,ihnp4}!arizona!asuvax!nelan
Arizona State University ...ihnp4!noao!terak!asuvax!nelan
Tempe, Arizona, USA, 85287 CSNET:
(602)-965-2791 nelan@asu