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Subject: Re: [Boost-users] [Timer] Using progress timers.
From: Gordon Woodhull (gordon_at_[hidden])
Date: 2011-09-21 13:22:32

On Sep 21, 2011, at 8:05 AM, Lars Viklund wrote:

> On Wed, Sep 21, 2011 at 11:47:35AM +0100, Robert Jones wrote:
>> Hi All,
>> #include <boost/progress.hpp>
>> boost::progress_timer t;
>> 0.00 s
>> I was expecting a number >= 5.00 s! What am I missing?
> According to the docs for progress_timer, it uses clock().
> The man page for clock(3) on my system claims:
> * The clock() function returns an approximation of processor time used
> * by the program.
> That doesn't seem to refer to wall time, so I would recommend you to
> file a bug against this library.

Yes, this is a well known problem with Boost.Timer. Imagine the fun you can have trying to time the speedup of a multicore program with such a timer.

for Beman's proposed replacement. Vicente Botet is also working on a Stopwatches library based on Chrono for much the same purpose.


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