Geant4 - an Object-Oriented Toolkit for Simulation in HEP
Example ThreadsafeScorers
This example demonstrates a very simple application where an energy
deposit and # of steps is accounted in thread-local (i.e. one instance per
thread) hits maps with underlying types of plain-old data (POD) and global
(i.e. one instance) hits maps with underlying types of atomics.
The example uses a coarse mesh, extensive physics, and step limiters
to ensure that there is a higher degree of conflict between threads
when updating the scorers to test the robustness of the atomics
classes and maximize the compounding of thread-local round-off error.
At the end of the simulation, the scorers are printed to
"mfd_<DATA_TYPE>_<SCORER_TYPE>.out", where DATA_TYPE is either
"tl" (thread-local) or "tg" (thread-global) and SCORER_TYPE is "EnergyDeposit"
or "NumberOfSteps". These values are then compared to a thread-global
sum of these scorers that were updated via mutex locking. If round-off
errors in thread-local EnergyDeposit are present, they can be viewed
in "mfd_diff.out" at the end of the simulation
SEE ALSO: README
