get high resolution time. the resolution is nanoseconds with 64 bits integer.
Contemporary CPUs have some counters in itself, such as 'Time Stamp
Counter' in Intel Pentium series, or 'TICK counter' in Sparc
processors. One of the counters is
incremented every clock cycles, e.g. in case of intel pentiumIII 1GHz
gets the resolution of nanoseconds(1/1,000,000,000 sec).
This method is fastest at runtime, but most difficult at
implementation. It needs a programming in assembly language. Currently
APerf supports i386 and sparc.
When you want to use this method, you need to tell APerf your CPU
clock in MHz or KHz to the library with setting a environment
variable.
The easiest way to implement, heaviest at runtime. but most common method.
Connections: 300 start(+0), 300 end, max concurrence 4 Time(ms): 300 samples, min 9, max 631, med 25, stddev 109.1, avg 44.5 75-95 percentile by 5, 25 25 25 25 26 4.81user 5.19system 0:10.00elapsed 100%CPU (0avgtext+0avgdata 0maxresident)k 0inputs+0outputs (18major+4minor)pagefaults 0swaps