how to call accurate sleep

[haijie1223]

On 2011/12/19 at 3:05 AM, KaFu said:

Give this one a try...

 

 

$h_DLL_NtDll = DllOpen("ntdll.dll")

$Delay_value = GUICtrlRead($Delay)
If WinExists("Notepad") Then
    WinActivate("Notepad")
    _HPSleep($Delay_value)
Else
    MsgBox(0, "Wrong Window", "Open Up Nitto n00b")
EndIf

Func _HPSleep($fMs = 1)
    ; http://www.autoitscript.com/forum/topic/77905-sleep-down-to-100-nano-seconds/page__view__findpost__p__862689
    ; default is milliseconds, otherwise microseconds (1 ms = 1000 µs)
    DllCall($h_DLL_NtDll, "dword", "NtDelayExecution", "int", 0, "int64*", -10000 * $fMs) ; ~ 1ms
EndFunc   ;==>_HPSleep

Why the Second param *(-1)

[Subz]

You do realise this is a 6 year old post?  What param are you referring to?

[KaFu]

https://forum.powerbasic.com/forum/user-to-user-discussions/source-code/56824-ntdelayexecution-sleep-sleepex-with-higher-resolution-absolute-delay

Quote

NtDelayExecution() takes a 64-bit integer (QUAD) as the time-to-sleep, vs 32-bit (DWORD) for Sleep()/SleepEx().

If this is a NEGATIVE integer it specifies the relative time to sleep (in units of 100 nanoseconds), otherwise it specifies the absolute time to wake up (the latter being a feature of it which neither Sleep()/SleepEx() cater for -- we have to call NtDelayExecution directly to use that feature).

Example, using relative time, for the equivalent to Sleep(2500), ie. sleep for 2.5 seconds, we specify -25000000 as the interval with NtDelayExecution(). Using absolute time (which is exclusive to NtDelayExecution and cannot be used via Sleep/SleepEx) we simply get the current system time (UTC, so we use GetSystemTime not GetLocalTime), convert that to filetime, and add 25000000 to the dwLowDateTime field.

 

[haijie1223]

On 2017/3/25 at 5:03 PM, KaFu said:

https://forum.powerbasic.com/forum/user-to-user-discussions/source-code/56824-ntdelayexecution-sleep-sleepex-with-higher-resolution-absolute-delay

 

Thanks