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Time Conversion Routines

The Driver Services Library provides the following conversion routines to convert between Nanoseconds, Duration, and AbsoluteTime units:



 
Nanoseconds AbsoluteToNanoseconds (AbsoluteTime absoluteTime);



 


Nanoseconds DurationToNanoseconds (Duration duration);



 


Duration AbsoluteToDuration (AbsoluteTime absoluteTime);



 


AbsoluteTime NanosecondsToAbsolute (Nanoseconds nanoseconds);



 


AbsoluteTime DurationToAbsolute (Duration duration);



 


Duration NanosecondsToDuration (Nanoseconds nanoseconds);



 


AbsoluteTime AddAbsoluteToAbsolute(

                     AbsoluteTime absoluteTime1,

                     AbsoluteTime absoluteTime2);



 


AbsoluteTime SubAbsoluteFromAbsolute(

                     AbsoluteTime leftAbsoluteTime,

                     AbsoluteTime rightAbsoluteTime);



 


AbsoluteTime AddNanosecondsToAbsolute(

                     Nanoseconds nanoseconds,

                     AbsoluteTime absoluteTime);



 


AbsoluteTime AddDurationToAbsolute(

                     Duration duration,

                     AbsoluteTime absoluteTime);



 


AbsoluteTime SubNanosecondsFromAbsolute(

                     Nanoseconds nanoseconds,

                     AbsoluteTime absoluteTime);



 


AbsoluteTime SubDurationFromAbsolute(

                     Duration duration,

                     AbsoluteTime absoluteTime);



 


Nanoseconds AbsoluteDeltaToNanoseconds(

                     AbsoluteTime leftAbsoluteTime,

                     AbsoluteTime rightAbsoluteTime);



 


Duration AbsoluteDeltaToDuration(

                     AbsoluteTime leftAbsoluteTime,

                     AbsoluteTime rightAbsoluteTime);

Note

The value of rightAbsoluteTime is usually larger than that of leftAbsoluteTime. However, if you subtract a rightAbsoluteTime value from a leftAbsoluteTime value, the result is 0, not a negative number.

EXECUTION CONTEXT

The time conversion routines may be called from task level, secondary interrupt level, or hardware interrupt level.