DRootGeom

[David Lawrence <davidl@jlab.org>]

Hi Folks,

    I've just committed changes to the DRootGeom class used for 
accessing the material for use
in tracking. Please find the svn comment below. This change is primarily 
aimed at overcoming
 the problem with seg. faults when running with multiple threads. The 
changes include some
to make the original scheme thread safe at a considerable perfomance 
cost and others to do a
table look-up which will be inherently thread-safe. This second option 
is not yet the default
pending final testing. Results for this will be presented at some near 
future meeting.


-Add lookup table option to DRootGeom::FindMat in order to avoid 
 multi-threading option. This also may give better results since
 it averages material from 80 points for every table entry

-Added mutex protection to low-level material access so that it
 can be used with multiple threads, albeit with significant slow-
 down.

The default option is to use the original routine (with mutex)
and not the table for now until further testing is done.


-David

-- 

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 David Lawrence Ph.D.
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