On 2010-02-09, Jean-Michel Pichavant <jeanmic...@sequans.com> wrote:
> Grant Edwards wrote:
>> What's the correct way to measure small periods of elapsed
>> time. I've always used time.clock() in the past:
>>
>> start = time.clock()
>> [stuff being timed]
>> stop = time.clock()
>>
>> delta = stop-start
>>
>> However on multi-processor machines that doesn't work.
>> Sometimes I get negative values for delta. According to
>> google, this is due to a bug in Windows that causes the value
>> of time.clock() to be different depending on which core in a
>> multi-core CPU you happen to be on. [insert appropriate
>> MS-bashing here]
>>
>> Is there another way to measure small periods of elapsed time
>> (say in the 1-10ms range)?
>>
>> Is there a way to lock the python process to a single core so
>> that time.clock() works right?
>>
>>
>
> Did you try with the datetime module ?
No. What mechanism does it use to get the current date/time?
> import datetime
> t0 = datetime.datetime.now()
> t1 = t0 - datetime.datetime.now()
> t1.microseconds
> Out[4]: 644114
That looks very broken to me. I need to measure stuff in the
1-20ms range, and the smallest value you can measure using the
method above appears to be 640ms. Thats almost 2/3 of a second.
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Grant Edwards grante Yow! If our behavior is
at strict, we do not need fun!
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