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Added TIMSRV.

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Resolves #245.
This commit is contained in:
Eric Swenson
2016-12-18 15:27:55 -08:00
parent d64ba80388
commit e29d6907c1
4 changed files with 183 additions and 0 deletions
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106
src/sysnet/timsrv.10 Executable file
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;-*- Mode: MIDAS -*-
TITLE TIMSRV ; Net time server
GMTDIF==5 ; # hours difference between local zone and GMT.
F=0 ;TCP flag.
A=1
B=2
C=3
P=17
NETO==1
NETI==2
.INSRT KSC;MACROS >
LOC 42
JSR TSINT
LOC 100
PAT: BLOCK 20
PDL: BLOCK 20
DEBUG: 0
ICPSOC==45 ; Official ICP socket for Time Server.
;Interrupt handler - mostly for fatal conditions
TSINT: 0
0
JSR LOGOUT ; Any interrupt is cause for death.
; Start of program
GO: MOVEI P,PDL ;init pdl pointer
.SUSET [.RJNAME,,A]
CAME A,[SIXBIT /TCP/]
JRST NCPICP
TCPICP: SYSCAL TCPOPN,[ MOVEI NETI ? MOVEI NETO
MOVEI ICPSOC ? [-1] ? [-1]]
JSR LOGOUT ; Failed (should timeout!)
MOVEI B,3*30. ; Try for 30 sec
TCPIP1: MOVEI A,10.
.SLEEP A,
SYSCAL WHYINT,[MOVEI NETO ? MOVEM A ? MOVEM A]
.LOSE %LSSYS
CAIE A,%NSOPN
CAIN A,%NSRFN
CAIA
SOJG B,TCPIP1
CAIG B,
JSR LOGOUT ; Timed out...
SETO F,
JRST SERVE ; Or got connected...
;set timer to log out if icp not finished within 60 sec.
NCPICP: MOVE A,[600000,,[60.*60.]] ;flush old ticks, start
.REALT A, ;new rate, 60 sec frame(ints).
JFCL
.SUSET [.SMASK,,[%PIRLT+%PIIOC]] ;enable ioc and realt
.SUSET [.SPICLR,,[-1]] ;enable ints
;start icp
.OPEN NETO,[40060+.UIO,,'NET ? ICPSOC] ;open 32-bit listen on ICP socket.
JSR LOGOUT
MOVEI A,NETO
NETHANG 900.,A,%NSLSN,[%NSRFC] ;hang until rfc received
JSR LOGOUT
.NETAC NETO, ;accept it
JSR LOGOUT
MOVEI A,NETO
NETHANG 900.,A,%NSRFC,[%NSOPN] ;wait until open
JSR LOGOUT
SETZ F,
SERVE: .RLPDTM A, ; Get in A, # secs since beg of year.
CAME A,[-1]
CAMN B,[-1]
JSR LOGOUT ; If either is -1, time not known.
CAIGE B, ; If 4.9 on,
SUBI A,24.*3600. ; subtract 1 day - .RLPDTM misfeature!
TLNE B,100000 ; Bit 4.7 = Daylight Savings time?
SUBI A,3600. ; If on, subtract one hour to get Standard.
MOVEI B,-1900.(B) ; Get year, relative to 1900.
MOVEI C,-1(B) ; Adjust and
LSH C,-2 ; Get # leap years since 1900
; not including this year.
IMULI B,365. ; Find # days in years thus far
ADDI B,(C) ; Plus # LY's, to get total days in years past.
IMULI B,86400. ; Now get # seconds in all them days.
ADD A,B ; and produce total seconds since 1/1/00 !
ADD A,[GMTDIF*3600.] ; Adjust to GMT.
SKIPN F ; If connected via NCP
JRST [ .IOT NETO,A ; Send out a word of the 32-bit time.
JRST SRVDUN ]
MOVE B,[401000,,A] ; If connected via TCP
MOVEI C,4. ; Send four 8-bit bytes of the 32-bit time.
SYSCAL SIOT,[MOVEI NETO ? B ? C]
JSR LOGOUT
SRVDUN: .NETS NETO, ; Force the output.
.CLOSE NETO, ; Disconnect.
CAIA
LOGOUT: 0
SKIPE DEBUG
.VALUE
.LOGOUT ; All done
END GO

71
src/sysnet/timsrv.info Executable file
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Date: 30 AUG 1976 1202-PDT
From: POSTEL at USC-ISIC
Subject: Time Of Day Socket Number
To: KLH at MIT-AI
cc: postel
Ken:
The number is 37 decimal (45 octal).
--jon.
-------

RMS@MIT-AI 08/15/76 19:35:47
To: KLH at MIT-AI
I forgot to say in the time algorithm
that a sublist is acceptible only if it contains at least half
the hosts that responded. If there is no sublist, all the hosts
get mailed messages. The intent if the messages is to get
people on the hosts to intervene.

RMS@MIT-AI 08/15/76 16:48:11
To: KLH at MIT-AI
I would like to have the system's time itself set according
to the other sites' times. I have worked out an algorithm
that I think does the right things in all cases:
1) contact all the sites on the list.
2) make a list of all the sites that gave answers,
and what they gave, including the local host.
Contact all of them in parallel to save real time.
3) sort that list numerically by time returned.
4) find the longest subsequence which has the property
that its beginning and end are within 5 minutes.
"Length" can actually be weighted, with more related hosts
counting for more.
5) compute the average time of the hosts in the sublist
6) Send mail to the appropriate name at all hosts not in
that sublist, telling them the names of the hosts in the
sublist and the amount of time they're off from the sublist
average.
7) If the local host isn't in the sublist, set its time
to the sublist average.
8) this program should be run whenever the system starts up,
and everything else should wait for its completion.
Thus, it should be done by TARAKA before anything else.
KLH@MIT-AI 08/15/76 03:32:42
To: RMS at MIT-AI
CC: [KSC;TIMSRV INFO] at MIT-AI
P.S. to message about time server etc. The following routines
are fairly modular:
NETIM - in TIMES >, is a non-interrupt routine that gets the "network time word"
given a site # to connect to.
TIMGTN - in TIMRTS >, is a routine that returns current local time in
network-time format.
TIMCAS/TIMCAD - in TIMRTS >, will convert network-time format into standard
DSK-style format.
Since hacking time stuff is so painful, however straightforward,
I thought I would point those out, particularly TIMCAS. The network-time
format is # seconds since 1/1/1900, GMT - this makes instant
comparisions easy from any point in network, and is simple enough to
encode. It is much more of a win than I thought it would be; TIMES^K
scans very fast.
The algorithm mailer uses is to poll all sites known
to have Time Servers, and proceed with its local time if it agrees
with more sites than it disagrees, or if all sites are down. This
implies that finding 1 match and 1 mismatch will cause mailer to
hang up and wait, but 2 matches and 1 mismatch will be taken as confirmation
of local time. Criteria for a match is that the absolute difference
must not be more than 15 minutes, which is extremely liberal I think.