2010/5/30 Bernard Marcelly <marce...@club-internet.fr>:
> Message de Konstantin Tokarev date 2010-05-29 19:10 :
>>
>>> On MS-Windows the result is in milliseconds, with a precision of 16 ms
>>> due to IBM PC hardware design.
>>
>> Does it mean that results of OOo Basic scripts may be platform-dependent?
>>
>
> Help says it depends on OS. I have not tested on other OS than MS-Windows,
> nor on other HW platform, e.g. Mac.
> Help shows how to count the ticks for a given delay.
>
> This code shows on PC/MS-Windows that GetSystemTicks does not increment by
> 1.
>
> Dim t1 As Long, t2 As Long, n As Long
> n = 0
> t1 = GetSystemTicks
> Do
> t2 = GetSystemTicks -t1
> n = n+1
> Loop Until t2 <> 0
> MsgBox("t2 = " & t2 & " n = " & n)
>
> Regards
> Bernard
Maybe I was wrong about the getSystemTicks() function. It seems like
it actually measures time in ms, not just CPU time. At least my
experiments point in that direction:
REM ***** BASIC *****
Option Explicit
Sub Main
Dim t1 As Double, t2 As Double, n As Long, st as Long
n=0
t1=now()
st=GetSystemTicks()
Do
t2=now()
n=n+1
Loop Until (t2-t1)*86400>=100 ' Approximately 100 seconds
MsgBox("Ticks/s: " & GetSystemTicks()-st & chr(13) & _
"Loop: " & n & chr(13) & "t1= " & t1 & chr(13) & _
"t2= " & t2 & chr(13) & "t2-t1= " & t2-t1 & _
chr(13) & "In s: " & (t2-t1)*86400)
End Sub
Maybe something is wrong with my code, because sometimes it runs for
an extra second. Run it in just one second instead of 100:
REM ***** BASIC *****
Option Explicit
Sub Main
Dim t1 As Double, t2 As Double, n As Long, st as Long
n=0
t1=now()
st=GetSystemTicks()
Do
t2=now()
n=n+1
Loop Until (t2-t1)*86400>=1 ' One second only
MsgBox("Ticks/s: " & GetSystemTicks()-st & chr(13) & _
"Loop: " & n & chr(13) & "t1= " & t1 & chr(13) & _
"t2= " & t2 & chr(13) & "t2-t1= " & t2-t1 & _
chr(13) & "In s: " & (t2-t1)*86400)
End Sub
Now the ticks result should be somewhere between 0 and 999, right? It
usually is, but now and then it's almost 2000. The n variable tells us
how many times it looped, like in your example above, and it runs
quite a few times for one tick, so why doesn't it realize that it's
time to stop until (t2-t1)*86400 almost reaches 2?
Yes, a bit out of topic, I know, but still interesting to know…
For example one of the outputs is like this:
Ticks/s: 1605
Loop: 43638
t1= 40328,4520717593
t2= 40328,4520949074
t2-t1= 2,31481462833472E-05
In s: 1,99999983888119
Why didn't it stop until (t2-t1)*86400≈2? It should have been ⩾1
thousands of times before that, shouldn't it?
Johnny Rosenberg
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