[fpc-pascal] Efficient millisecond timestamp

[Mark Morgan Lloyd]

Michael Van Canneyt wrote:
> On Fri, 10 Jan 2014, Mark Morgan Lloyd wrote:
> 
>> What's the most efficient and portable way of getting a millisecond 
>> timestamp, relative to any ancient epoch? I find
>>
>> TimeStampToMSecs(DateTimeToTimeStamp(Now))
>>
>> hard to swallow since Now() is hardly efficient and the resulting Comp 
>> is marked as non-potable in the documentation.
> 
> Where does it say that ?

http://www.freepascal.org/docs-html/prog/progsu157.html#x200-2050008.2.5 
"On other processors, the comp type is not supported."

> And why do you think now returns a comp ? It returns a double.

http://lazarus-ccr.sourceforge.net/docs/rtl/sysutils/timestamptomsecs.html 
returns comp.

And I hardly see the point of converting something coming from the 
hardware and/or a kernel counter to a double and then back to a quadword.

-- 
Mark Morgan Lloyd
markMLl .AT. telemetry.co .DOT. uk

[Opinions above are the author's, not those of his employers or colleagues]