Dear All,
In an application that I'm writing I need a way to 'block' computations
for very short periods of time. I thought at first that Delay would do
the job, but running
for I in 0..1000;10 do T1 T2 in
T1 = {Property.get 'time.total'}
{Delay I}
T2 = {Property.get 'time.total'}
{ShowInfo I#'\t'#T2-T1#'\t'#{Int.toFloat (T2-T1)}/{Int.toFloat I}}
end
shows that (at least under Windows) results of calls to {Delay I} aren't
very precise: {Delay 10} delays for 16 ms, {Delay 20} for 31 ms, {Delay
100} for 109 ms, etc. See the table produced by the above code at the
end of this message. (On the other hand I've noticed that I do get exact
times for {Delay I} when I are multiples of 125 - if that's by
coincidence, I don't know..?. )
Now, I've read about Delay in CTM and I think I understand the above
behaviour. {Delay I} suspends the calling thread T for *at least* I ms,
and when T is allowed to run again, it is subject to the ordinary thread
scheduling mechanism, which means that it may take a bit longer to
actually run. So I guess Delay does what it is supposed to do. The fact
remains that I need timing more exact than that though, so here are my
questions:
- Is it possible to write a version of Delay which is more exact for
small Is?
- Is there anything else that I can use? {MyDelay I} does not
necessarily have to suspend the calling thread - it can just eat cycles
from it - not too many though...
- Is the exactness of {Delay I} when I are multiples of 125 something I
can rely on?
Cheers,
Torbjörn
I T I/T
=== === =====
0 0 -1.#IND
10 16 1.6
20 31 1.55
30 31 1.03333
40 47 1.175
50 63 1.26
60 62 1.03333
70 78 1.11429
80 94 1.175
90 94 1.04444
100 109 1.09
110 125 1.13636
120 125 1.04167
130 141 1.08462
140 141 1.00714
150 156 1.04
160 172 1.075
170 172 1.01176
180 187 1.03889
190 203 1.06842
200 203 1.015
210 219 1.04286
220 234 1.06364
230 235 1.02174
240 250 1.04167
250 250 1.0
260 265 1.01923
270 282 1.04444
280 281 1.00357
290 297 1.02414
300 312 1.04
310 313 1.00968
320 328 1.025
330 344 1.04242
340 343 1.00882
350 360 1.02857
360 375 1.04167
370 375 1.01351
380 390 1.02632
390 391 1.00256
400 406 1.015
410 422 1.02927
420 422 1.00476
430 438 1.0186
440 453 1.02955
450 453 1.00667
460 469 1.01957
470 484 1.02979
480 484 1.00833
490 500 1.02041
500 500 1.0
510 516 1.01176
520 531 1.02115
530 531 1.00189
540 547 1.01296
550 563 1.02364
560 562 1.00357
570 578 1.01404
580 594 1.02414
590 594 1.00678
600 609 1.015
610 625 1.02459
620 625 1.00806
630 641 1.01746
640 641 1.00156
650 656 1.00923
660 672 1.01818
670 672 1.00299
680 687 1.01029
690 703 1.01884
700 703 1.00429
710 719 1.01268
720 734 1.01944
730 735 1.00685
740 750 1.01351
750 750 1.0
760 765 1.00658
770 782 1.01558
780 781 1.00128
790 797 1.00886
800 812 1.015
810 813 1.0037
820 828 1.00976
830 844 1.01687
840 843 1.00357
850 860 1.01176
860 875 1.01744
870 875 1.00575
880 890 1.01136
890 891 1.00112
900 906 1.00667
910 922 1.01319
920 922 1.00217
930 938 1.0086
940 953 1.01383
950 953 1.00316
960 969 1.00937
970 984 1.01443
980 984 1.00408
990 1000 1.0101
1000 1000 1.0
_________________________________________________________________________________
mozart-users mailing list
[email protected]
http://www.mozart-oz.org/mailman/listinfo/mozart-users
