[PATCH v2] Test for clock_nanosleep with CLOCK_MONOTONIC option.

[Sebastian Huber]

On 15/04/2020 14:29, Utkarsh Rai wrote:
> On Wed, Apr 15, 2020 at 5:35 PM Sebastian Huber 
> <sebastian.huber at embedded-brains.de 
> <mailto:sebastian.huber at embedded-brains.de>> wrote:
>
>     On 15/04/2020 14:02, Utkarsh Rai wrote:
>
>>         > +  status = clock_gettime( CLOCK_MONOTONIC, &end_time );
>>         > +  rtems_test_assert( status == 0 );
>>         > +
>>         > +  rtems_test_assert( (end_time.tv_sec-init_time.tv_sec) ==
>>         0 );
>>
>>         Is end_time.tv_sec - init_time.tv_sec == 0 under all
>>         circumstances?
>>
>>
>>     My idea was to check for a 1ns delay with a reasonable amount of
>>     overhead, hence I checked for  end_time.tv_sec - init_time.tv_sec
>>     == 0.
>     Exists there a value of init_time for which end_time.tv_sec !=
>     init_time.tv_sec and still 1ns elapsed?
>
>
> Sorry, maybe I am confused in my concept, kidly help me out. I want to 
> produce a 1ns delay, so I make a call to clock_nanosleep with flag 
> value as 0 (to sleep for specified time) and the delay being 1ns. I 
> recorded the time before the sleep call and after the sleep call. Now, 
> I want to check if the delay produced was actually 1ns with a 
> reasonable overhead, my assumption for an unreasonable overhead was 
> that if I specify a delay of 1ns
Up to here everything is fine.
> and I get a delay in seconds, it would be an error.
Think about this once more.
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