Re: [Gcl-devel] Re: time on Mac

[Camm Maguire]

Greetings, and thanks again, Aurelien!

Actually, get-internal-run-time is a wrapper around *times*, not time,
which has the advantage of separating out user, system, and child
times.  I think this is important, especially as running gcc in gcl
can be such a significant portion of actual time in many
circumstances.  Such a separation is not possible, with gettimeofday,
right?  If not, I'd suggest we just get the HZ conversion right,
otherwise I have no problem with synchronizing on gettimeofday.

Take care,

Aurelien Chanudet <address@hidden> writes:

> Hi,
> 
> The odd results you're reporting about are due to an
> inconsistency between time(3) and gettimeofday(2) :
> get-internal-real-time is a wrapper around
> gettimeofday(2) while get-internal-run-time is a
> wrapper around time(3).
> 
> gcl relies on the number of clock ticks per second
> (see comment at the beginning of o/unixtime.c) : the
> conversion factor HZ is expected to be defined
> somewhere in <sys/param.h>. If no conversion factor is
> present, a default conversion factor of 60 is assumed.
> 
> On MacOS X, there's no no conversion factorin
> <sys/param.h>. As a result, a probably wrong
> conversion factor is assumed, thus leading to odd
> results.
> 
> My advice is that time(3) should be changed in favor
> of gettimeofday(3). Camm what do you think ?
> 
> Aurelien
> 
> > Greetings!
> > 
> > o/unixtime.c.  Time macro in lsp/gcl_mislib.lsp.
> > 
> > Please let me know if you need further explanation. 
> > And thanks for
> > looking into this!
> > 
> > Take care,
> > 
> > 
> > Aurelien Chanudet <address@hidden> writes:
> > 
> > > Hi Bob and Warrem,
> > > 
> > > > > It seems that there is something odd about the
> > > > time function on the Macintosh
> > > > > version of GCL (version 2.6.4).  In the
> > following
> > > > example, the sum of run-gbc
> > > > > and gbc time is about 60% greater than the
> > real
> > > > time.  In fact, gbc time is
> > > > > even greater than real time!
> > > 
> > > Camm, can you please point me to the underlying C
> > > source file which is responsible for calling Unix
> > time
> > > management functions (I suppose this is what
> > happens)
> > > ?
> > > 
> > > > >    (time (loop for i from 1 to 10 do
> > (make-list
> > > > 1000000)))
> > > > > 
> > > > >    real time       :      2.667 secs
> > > > >    run-gbc time    :      1.100 secs
> > > > >    child run time  :      0.000 secs
> > > > >    gbc time        :      3.117 secs
> > > > > 
> > > > > We have also seen other strange results such
> > as
> > > > the following, which have
> > > > > run-gbc time way greater than real time, which
> > > > seems impossible.
> > > > > 
> > > > >    All Nqthm-1992 tests completed
> > successfully.
> > > > > 
> > > > >    real time       :   1360.783 secs
> > > > >    run-gbc time    :   1776.283 secs
> > > > >    child run time  :    221.300 secs
> > > > >    gbc time        :     46.750 secs
> > > > > 
> > > > > Warren and Bob
> > > > > 
> > > > > 
> > > > > 
> > > > 
> > > > -- 
> > > > Camm Maguire                                            address@hidden
> > > >
> > >
> >
> ==========================================================================
> > > > "The earth is but one country, and mankind its
> > > > citizens."  --  Baha'u'llah
> > > >  
> > > 
> > > 
> > >   
> > >   
> > >           
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> > > 
> > 
> > -- 
> > Camm Maguire                                                address@hidden
> >
> ==========================================================================
> > "The earth is but one country, and mankind its
> > citizens."  --  Baha'u'llah
> >  
> 
> 
>       
>       
>               
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-- 
Camm Maguire                                            address@hidden
==========================================================================
"The earth is but one country, and mankind its citizens."  --  Baha'u'llah