datetime review part 2

[Michel Fortin]

On 2010-11-26 08:59:58 -0500, Jonathan M Davis <jmdavisProg at gmx.com> said:

> On Friday 26 November 2010 04:38:47 Michel Fortin wrote:
> 
>> One thing I wonder about... what is the expected behaviour if you put
>> the computer to sleep in the middle of the above program? With
>> mach_absolute_time, the clock stops counting while the computer is put
>> to sleep. Does TickDuration.currSystemTick works like that on all
>> systems? If there's a difference in behaviour perhaps it should be
>> documented.
> 
> Really? That is... not good. Unacceptable in fact. Even if it were acceptable
> when dealing with stop watch and benchmarking code (which is questionable), it
> totally fries Clock.currAppTick(), which tells you how long the application has
> been running. The documentation for QueryPermanceCounter() and clock_gettime()
> give no indication that the clock stops counting when a thread is sleeping.

No no no... not when a *thread* is sleeping. When the *computer* is 
sleeping; when the OS is suspended while you close the lid on a laptop 
for instance. So I start my program, it enters the sleep() function, I 
close the lid, and one minute later I reopen it and when the sleep() 
function returns the tick duration is as if the clock was stopped while 
the lid was closed, despite that the real elapsed time was far much. 
Closing the lid puts the *computer* to sleep and stops the clock, not 
the sleap() function.

I understand my example using the sleep() function was misleading 
because the term sleep had two meanings.


-- 
Michel Fortin
michel.fortin at michelf.com
http://michelf.com/