Most Efficient Timer?

[Frank D. Engel, Jr.]

With send times that short, I would not be too worried about most of 
those readings.  The 2% usage for a 1 second timing is a bit more 
meaningful, and even this is not too bad (though I suspect it could be 
better).

Bear in mind that if running these tests in the dev environment, some 
of that percentage will be due to added overhead of the development 
environment.  You should likely test this with standalone apps to get a 
more meaningful measurement.

On a 500MHz G4 (OS 10.3.6), I created a new mainstack with a single 
checkbox.  The checkbox script is:

on x
   send "x" to me in 1 second
   set the hilite of me to not the hilite of me
end x


And the mainstack script:

on openStack
   send "x" to button "Check" in 1 second
end openStack


I then saved this and saved it as a standalone.  Activity monitor 
(updating every 2 sec) reports:

The Rev IDE with the stack open (and no others):  keeps shifting 
between 0.5%, 1%, 1.9%, 2%...

The standalone app: about the same, except that it occasionally drops 
as low as 0.4%, and I did see *one* flash of 3%.


Now changing the update interval to 0.5 sec:

CPU usage actually flashes from *zero* to as high as nearly 5%.


Now changing the update interval to 5 sec:

CPU usage switches from zero to about 1.9 or 2 percent.

Hint:  most of the time (CPU perspective) the usage is zero.  When 
updating the checkbox, the usage can jump to as high as nearly 5% for a 
brief period of time.  My guess is that the activity monitor is biased 
toward giving the higher readings.

I used the command-line 'time' utility to measure the runtime of the 
standalone.  The results after a few seconds were:

real    0m14.617s
user    0m0.890s
sys     0m0.230s

Combining user with system CPU time of the process yields about 1.12 
seconds, out of 14.617 seconds that the process was running.  This 
would suggest about 7.7% CPU usage.  Bear in mind that this includes 
startup time, displaying the window, initializing the engine, etc.

Now after a somewhat longer run:

real    1m6.203s
user    0m1.200s
sys     0m0.350s

This suggests usage of 1.55 second over the course of 66.203 seconds, 
for about 2.34% CPU usage.  Notice that this is much lower, and this is 
likely due to the fact that much of the startup time, etc. from the 
runs is a "one-time" issue.


Next experiment:

I created a new mainstack and saved it, then saved it as a standalone 
(no objects or scripts).  Now I run the 'time' command on this 
standalone:

real    0m47.594s
user    0m0.530s
sys     0m0.250s

This would be 0.78 second over 47.594 seconds, or 1.64% CPU usage -- 
with *NO OBJECTS OR SCRIPTS*.

This time is likely taken up by the Rev engine, so it would seem that 
the actual CPU usage of my little checkbox mechanism is only about 2.34 
- 1.64 = 0.7% CPU usage.  Hmm....


You can't always judge a book by its cover.


Do note that these percentages will likely decrease slightly with 
longer runtimes (flattening out because of startup time, 
initialization, etc.), but I have no reason to run the tests for that 
long, I think I made my point here.


On Nov 29, 2004, at 3:38 PM, Dar Scott wrote:

>
> On Nov 29, 2004, at 12:36 PM, Scott Rossi wrote:
>
>>> It looks to me that using "send in time" is efficient.
>>
>> Actually, I was referring to "efficiency" in terms of placing demands 
>> on the
>> system, not in the amount of time to process within Rev.
>
> Oh, I see what you mean.  I used Activity Monitor on OS X and got this:
>
> Send cycle (.1 s period):    16%
> Default Button:              29%
> Both:                        35%
>
> Send cycle (.05 s period)    35% (fluctuates a lot)
> Send cycle (.01 s period)   101%
> Send cycle (1 s period)       2%
>
> I'm on OS X 10.3.6 using a dual 1.25 GHz G4.
>
> Dar
> ****************************************
>     Dar Scott Consulting
>     http://www.swcp.com/dsc/
>     Programming Services
> ****************************************
>
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>
-----------------------------------------------------------
Frank D. Engel, Jr.  <fde101 at fjrhome.net>

$ ln -s /usr/share/kjvbible /usr/manual
$ true | cat /usr/manual | grep "John 3:16"
John 3:16 For God so loved the world, that he gave his only begotten 
Son, that whosoever believeth in him should not perish, but have 
everlasting life.
$