Oberon Task Statistics (Windows)

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2 total messages Started by Doug Danforth Fri, 12 Apr 1996 15:13

#1317

Author: Doug Danforth
Date: Fri, 12 Apr 1996 15:13

71 lines
2536 bytes

Folks,
  Have you ever wondered how much time is consumed by a cycle
of an Oberon task loop?  I've run several small programs and
would like to report the following results for Windows 95 Oberon
V4:

One tick:  	1 millisecond.
TightLoop: 	10,000 cycles/tick ( 60 MHZ Pentium)
  "             30,000    "         150  "    "
Task:      	50 ticks
Others.Wait:	50 ticks


Where by TightLoop I mean
	lastTime := Oberon.Time();
	i:=0; WHILE i<10000000 DO INC(i) END;
	time := Oberon.Time();

and by Task I mean

	PROCEDURE Start;
	BEGIN
	(* install Oberon.Task timer *)
	END Start;
	
	PROCEDURE Timer;
	BEGIN
	(* measure time from last activation of me *)
	END Timer;
	
	PROCEDURE Stop;
	BEGIN
	(* remove timer task *)
	END Stop;

And by Others.Wait I mean

	PROCEDURE Wait;
	BEGIN
	  IF Windows.GetMessage THEN 
	    Windows.TranslateMessage;
	    Windows.DispatchMessage;
	  END
	END Wait;

We see that the Oberon loop is totally dominated by the Windows
message handling mechanism (I belive WinV4 actually uses a
Windows Timer to call itself?).

This means that splitting a procedure into two task introduces 500,000 to 
one overhead! (2x -> (T+x) + (T+x)  where T >>> x).

I had not noticed this massive constraint until I switched from
Win3.11 to Win95 and my speech recording quality degraded (I am
pumping bytes into a modem which must be done in "real-time").
(I no longer have Win3.11 available so can not check the change
in task swap time).

Final note: The values of "50" are average, ranging from lows of
4 to highs of 110.

-Doug
-- 
-----------------------------------------------------------------------------
  Douglas G. Danforth, Ph.D.                       danforth@csli.stanford.edu
  Visiting Scholar                                 (415)723-2487 x332 vox  
  Applied Speech Technology Lab                    (415)725-2166 fax
  Center for the Study of Language and Information
  Ventura Hall                    
  Stanford University, Stanford CA.  94305-4115             
-----------------------------------------------------------------------------

Re: Oberon Task Statistics (Windows)

#1337

Author: zeller
Date: Tue, 16 Apr 1996 07:18

49 lines
1587 bytes

With the attached modules I mesured the following values (Win95 on P120)

	1.38E+4 Tasks/s using the standard System 3 for Windows
	1.24E+5 Taks/s using my experimental Multithreaded System 3 For Winows 95

In the multithreaded versions the Oberon.Loop does not poll the windows message queue.

Emi Zeller


MODULE TestTasks;
	IMPORT Input, Texts, Oberon;

	VAR
		T: Oberon.Task;
		count, time: LONGINT;
		W: Texts.Writer;

	PROCEDURE *Timer(me: Oberon.Task);
	BEGIN
		INC(count)
	END Timer;

	PROCEDURE Start*;
	BEGIN
		IF T = NIL THEN
			NEW(T); T.safe := FALSE; T.time := 0; T.handle := Timer;
			count := 0; time := Input.Time();
			Oberon.Install(T)
		END
	END Start;

	PROCEDURE Stop*;
	BEGIN
		IF T # NIL THEN
			time := Input.Time()-time;
			Oberon.Remove(T); T := NIL;
			Texts.WriteReal(W, count/(time/Input.TimeUnit), 20); Texts.WriteLn(W);
			Texts.Append(Oberon.Log, W.buf)
		END
	END Stop;

BEGIN
	T := NIL; Texts.OpenWriter(W)
END TestTasks.

TestTasks.Start
TestTasks.Stop

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