Re: Delayed response for sleep function

From: Gavin Lambert (boost_at_[hidden])
Date: 2022-06-21 00:48:13

On 20/06/2022 19:10, Daggumati, Rajesh wrote:
> When I use boost sleep function,  I am getting delayed response.
[...]
> output is :
>    10005
>    10006
> 
> Expected ouput should be 10000 and 10000

Sleep time is always a minimum bound, not exact, and is subject to the 
whims of the OS's thread scheduler.  You just have to live with that. 
Getting less than 10ms "drift" is actually an excellent result; on a 
loaded system it may be a lot worse than that.

There are some techniques that you can use to try to smooth out sleeps a 
bit (such as keeping track of the difference between requested and 
actual delay and adjusting your subsequent request accordingly), but 
these are rarely necessary (and are impossible to get "perfect" since 
they're only reactive; and can themselves be the source of bugs, 
especially in the presence of suspended power states), so they're not 
recommended for general use.

The best method of compensating for this sort of thing depends on 
exactly what you're actually trying to do; different goals call for 
different solutions.