AutoIt v3.3.11.4 Beta

[Melba23]

iCode,

When I run your code on my Win7 x86 system I get the following results:

Average over 100 Sleep(10):

3.3.10.2: 10.005
3.3.11.4: 10.120

I think the problem lies elsewhere.

M23

[Iczer]

I'm getting almost always 99 hits on range 15-16 ms and one to 5 to 13 ms

#include <Array.au3>
Local $array[1][20]

For $i = 1 To 100
    $t = TimerInit()
    Sleep(10)
    $n = TimerDiff($t)
    $array[0][Int($n)] += 1
Next
_ArrayDisplay($array)

[FaridAgl]

As far as I know, AutoIt's Sleep() function is different than the Sleep() function in the Kernel32.dll.

AutoIt uses timer to implement that, and that's exactly why the delay can't be less than 10ms.

 

Maximum sleep time is 2147483647 milliseconds (24 days) and the minimum is 10 milliseconds. So using 1-9 will automatically default to 10 milliseconds.

 

If you really need to sleep less than 10ms, try the other Sleep function.

DllCall("kernel32.dll", "none", "Sleep", "DWORD", 1)

But, seriously, use it only when you want to sleep less than 10ms.

[trancexx]

Currently the precision of Sleep depends on global Windows setting which can be influenced by any third party application. One user can really have 10ms sleep for Sleep(10), and some other can have, for example 24ms sleep period for the same call.

[jchd]

There is indeed significant dispersion in timed values.

Local Const $limit = 50000
Local $values[51]
Local $t, $n

For $i = 1 To $limit
    $t = TimerInit()
    Sleep(10)
    $n = Round(TimerDiff($t))
    $values[$n] += 1
Next
For $i = 0 To UBound($values) - 1
    $t = $values[$i]
    If $t Then
        $n = Round((800 * $t) / $limit) / 8
        $values[$i] = (Int($n / 8)) ? _StringRepeat(ChrW(0x2588), Int($n / 8)) : ''
        $n = Mod($n, 8)
        If $n Then $values[$i] &= ChrW(0x2588 + 8 - $n)
        $values[$i] &= ' ' & $t
    EndIf
Next
_ArrayDisplay($values)

I've found the need to increase possible times to 50ms since I've encountered values > 35ms.

The sample above was obtained while doing other foreground task.

[trancexx]

^^ You are just showing off. Like: "hey people look, I can draw graph using arraydisplay".

I like it.

[jchd]

It was more fun than mere timing!

It's prettier in console but that would need Unicode display.

All kind of asciified statistic graphs are useful within databases, using views, ad hoc statistic functions and a bit of care.

[iCode]

@Melba23 - try both 32 and 64 bit, release and beta - i would guess you'll probably experience very different results as i and @jchd did

@D4RKON3 - i agree, but just a note to others who stumble upon this that the dll call, in a tight loop with small values, will hog the CPU...

; CPU hog with small values...
While 1
    DllCall("kernel32.dll", "none", "Sleep", "DWORD", 1)
Wend

anyway, no big deal, but i think the help file should be updated to reflect the inaccuracy of Sleep at smaller values (so far it looks like values < 17 are problematic)

[Melba23]

iCode,

This are the results I get while simultaneously streaming and doing other foreground work as well on my x86 machine:

expandcollapse popup

Beta        Release
[0]|
[1]|
[2]|
[3]|
[4]|
[5]|
[6]|
[7]|
[8]|
[9]|  1140  1481
[10]| 45251 43852
[11]| 1003  1320
[12]| 544   653
[13]| 407   493
[14]| 271   371
[15]| 208   288
[16]| 169   201
[17]| 108   147
[18]| 112   103
[19]| 73    103
[20]| 61    82
[21]| 62    67
[22]| 48    66
[23]| 40    64
[24]| 32    39
[25]| 30    34
[26]| 21    43
[27]| 25    39
[28]| 22    49
[29]| 29    33
[30]| 17    36
[31]| 21    33
[32]| 16    27
[33]| 25    26
[34]| 16    30
[35]| 15    22
[36]| 20    14
[37]| 14    17
[38]| 9     15
[39]| 11    16  
[40]| 15    14
[41]| 17    13
[42]| 14    17
[43]| 7     7
[44]| 3     15
[45]| 5     13
[46]| 7     9
[47]| 7     6
[48]| 5     10
[49]| 7     4
[50]|

If you want to donate an x64 box for me to run tests on that I would be happy to do so.

But the main point I take from this is that if you want real timing accuracy then an interpreted language is probably not the best way to go given the inherent problems. But I will add something to the Help file explaining that the timings are only approximate and under 10 is not honoured at all.

M23

Edit: Added comment to Help file.

Edited April 19, 2014 by Melba23

[iCode]

thanks @Melba23

FYI, here's the note i made in a code snippet regarding the sleep dll call..

; however, do NOT make the DllCall() if the sleep is going to be repeated in a tight loop, else funny things happen outside of script, such as Ctrl+L-click gets whacky when selecting multiple objects in Explorer