+- PowerBASIC Users Meeting Point (http://pump.richheimer.de)
+-- Forum: User to User Discussions (http://pump.richheimer.de/forumdisplay.php?fid=3)
+--- Forum: Programming (http://pump.richheimer.de/forumdisplay.php?fid=7)
+--- Thread: Comments re High resolution replacement for Sleep (/showthread.php?tid=74)
Pages:
1
2
Comments re High resolution replacement for Sleep - David Roberts - 09-14-2025
I had a bit of a 'carrry on' creating post #2. I couldn't figure out the difference between 'Quick Edit' and 'Full Edit'. On one occasion, I got post #1 merging with post #2. On another occasion, I got post #2 being duplicated within itself.
Would someone explain the difference?
Anyway, the question is whether to use SleepX or SleepXX. I cannot answer that - only you can by trying the two source codes. On my Windows 10 machine with a Performance Counter Frequency of 10MHz and a CPU Base Frequency of 3.5GHz SleepXX is the more accurate.
If you have the time, would you let me know what your Performance Counter Frequency is, your CPU Base Frequency, and a console output of the more accurate.
Ta much.
RE: Comments re High resolution replacement for Sleep - Stuart McLachlan - 09-14-2025
Instead of a preprogrammed Base Frequency macro, you can determine it at run time so your code is not machine specific
'
Code:
#COMPILE EXE
#DIM ALL
#INCLUDE "win32api.inc"
GLOBAL CPUBaseFreq AS QUAD
FUNCTION PBMAIN () AS LONG
CPUBaseFreq = GetBaseCPUFreq
? "CPU Base Frequency: " & STR$(CPUBaseFreq) & " Hz"
'...
END FUNCTION
FUNCTION GetBaseCPUFreq() AS QUAD
LOCAL retval , hkey AS DWORD
LOCAL MHz AS DWORD
retval = RegOpenKeyEx( %HKLM,"HARDWARE\DESCRIPTION\System\CentralProcessor\0" ,0,%key_query_value,hkey)
retval = regqueryvalueex(hkey,"~Mhz",0,%REG_DWORD,MHZ,4)
retval = regclosekey(hkey)
FUNCTION = MHZ * 10 ^6
END FUNCTION
'RE: Comments re High resolution replacement for Sleep - David Roberts - 09-14-2025
Thanks, Stuart
I am getting 'Undefined equate' on line #14 - RegOpenKeyEx
RE: Comments re High resolution replacement for Sleep - Dale Yarker - 09-14-2025
Class A/class B amplifier analogy is backwards, so actually detracts from explanation of SLEEPXX.
A class A amp wastes power by being half on at zero input. Typically, one, or more (in series), class A amps drive a high(er) power class B amp that has both active drive components off when input is zero.
Is it too late to edit out?
No comment, either way, on SLEEPXX code ATT; though better resolution is a good thing.
Cheers,
RE: Comments re High resolution replacement for Sleep - David Roberts - 09-14-2025
Stuart's code works if simply add: %HKLM = &H80000002???
RE: Comments re High resolution replacement for Sleep - Stuart McLachlan - 09-14-2025
(09-14-2025, 03:19 AM)David Roberts Wrote: Thanks, Stuart
I am getting 'Undefined equate' on line #14 - RegOpenKeyEx
Sorry , I used José's includes which has the equate:
%HKLM = %HKEY_LOCAL_MACHINE
With PB includes, you have to specify the root key in full:
retval = RegOpenKeyEx( %HKEY_LOCAL_MACHINE,"HARDWARE\DESCRIPTION\System\CentralProcessor\0" ,0,%key_query_value,hkey)
RE: Comments re High resolution replacement for Sleep - David Roberts - 09-14-2025
Thanks, Dale. My taking a wrong turn on the analogies isn't relevant. The results with SleepX and SleepXX speak for themselves.
Thanks, Stuart.
RE: Comments re High resolution replacement for Sleep - Stuart McLachlan - 09-14-2025
Couldn't work out why replacing the macro with the function didn't work. Finally realised that I had to change /10^15 to *10^3 to get the correct values!
Took a bit of time to work out that the issue was the macro substitution messing up the order of operations in the calculation.
The macro is not replacing CPUBaseFreq with the VALUE of 3.5*10^9, it is replacing it with the STRING 3.5*10^9 in the source code, which resulted in a difference order of calculation and a vastly different magnitude of the result.
So qTime/CPUBaseFreq
became
qTime/3.5*10^9
which is not the same as
qTime/(3.5*10^9)
(I guess the 10^15 was derived by trial and error since it has no logical basis when dividing tix by hertz
)
RE: Comments re High resolution replacement for Sleep - David Roberts - 09-14-2025
Oops.
Post #3 at the source code forum incorporates your GetBaseCPUFreq.
There is no need for the offending macro now.
Thank you, Stuart.
RE: Comments re High resolution replacement for Sleep - Dale Yarker - 09-14-2025
"If you have the time, would you let me know what your Performance Counter Frequency is, your CPU Base Frequency, and a console output of the more accurate."
Performance Counter Frequency = 10.0 Mhz
CPU Base Frequency = 2.712 GHz
In SLEEPXX
IF <= 3 THEN removed
leaving:
tix qTimeNow
qTarget = qTimeNow + n*CPUBaseFreq*0.001
ELSE and below removed
console output:
Code:
Quarter of a millisecond: 0.25011 ms
0 seconds:0.000915 ms
2 seconds:2000.00025 ms
Silly:1234.000192 ms
01 1.000569 ms
02 2.000056 ms
03 3.00005 ms
04 4.000054 ms
05 5.000057 ms
06 6.000113 ms
07 7.000098 ms
08 8.000083 ms
09 9.000107 ms
10 10.000101 ms
11 11.000195 ms
12 12.000125 ms
13 13.000153 ms
14 14.000107 ms
15 15.000118 ms
16 16.000076 ms
17 17.000116 ms
18 18.00092 ms
19 19.000202 ms
20 20.000146 ms
21 21.000116 ms
22 22.000131 ms
23 23.000065 ms
24 24.000117 ms
25 25.000121 ms
26 26.000182 ms
27 27.0003 ms
28 28.000197 ms
29 29.000107 ms
30 30.000088 ms