Re: [boost] [chrono] Thread clock compatibility problems on Android

Subject: Re: [boost] [chrono] Thread clock compatibility problems on Android
From: Libor Bus (libor.bus_at_[hidden])
Date: 2011-05-16 04:48:47

Beman Dawes wrote:
> 
> Libor,
> 
>> Log outputs from Android emulator are:
>> times()-begin: c1=13829 tm1.tms_stime + tm1.tms_cstime=18, tm1.tms_utime
>> +
>> tm1.tms_cutime=638
>> times()-end: c2=13966 tm2.tms_stime + tm2.tms_cstime=18, tm2.tms_utime +
>> tm2.tms_cutime=670
>> real 0.001s, cpu 0.000s (23.9%), user 0.000s, system 0.000s
>> thread_clock: wall=1376ms, cpu=318ms
> 
> Could the problem be with the Android emulator rather than Android itself?
> 
> Google seems to find multiple reports of problems with the Android
> emulator related to time.
> 
> --Beman
> 

Hello Beman and Vicente,
it does not seem that the problem in stopclock test is caused by Android
emulator. I have similar results from Android HW (BeagleBoard xM) and Linux
PC (Ubuntu 11.04). Here is summary of stopclock test outputs on all tested
platforms:

Windows Vista:
stopwatches::stopclock<>: real 1.031s, cpu 0.031s (3.0%), user 0.031s,
system 0.000s
thread_clock: wall=1031ms, cpu=31ms 

Android emulator:
stopwatches::stopclock<>: real 0.001s, cpu 0.000s (23.2%), user 0.000s,
system 0.000s 
thread_clock: wall=1377ms, cpu=312ms 

Android on BeagleBoard:
stopwatches::stopclock<>: real 0.001s, cpu 0.000s (12.3%), user 0.000s,
system 0.000s
thread_clock: wall=1140ms, cpu=139ms

Linux Ubuntu 11.04 (x86):
stopwatches::stopclock<>: real 0.001s, cpu 0.000s (3.9%), user 0.000s,
system 0.000s
thread_clock: wall=1035ms, cpu=34ms

My impression is that text output of stopwatches::stopclock<> on
Android/Linux is 1000x less than shall be, so the printed values are not
seconds but milliseconds.

BR,
Libor

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