Author: Koichi Murakami (KEK) / Koichi.Murakami@kek.jp
G4MPI is a native interface with MPI libraries. The directory contains a Geant4 UI library and a couple of parallelized examples. Using this interface, users applications can be parallelized with different MPI compliant libraries, such as OpenMPI, LAM/MPI, MPICH2 and so on.
The MPI interface can work with MPI-compliant libraries, such as Open MPI, LAM/MPI, Intel MPI etc.
For example, the information about Open MPI can be obtained from http://www.open-mpi.org/
CMake is used to build G4MPI library, that co-works with Geant4 build system.
ROOT for histogramming/analysis
To build G4MPI library, use CMake on Geant4 library installed with CMake build.
Check CMakeList.txt
, especially the following two variables
should be taken care to match your MPI library
eg.
set(CMAKE_CXX_COMPILER mpicxx)
#set(CMAKE_CXX_INCLUDE_PATH ) set if necessary
Follow these commands,
> cd source
> mkdir build
> cd build
> cmake -DGeant4_DIR=<your Geant4 install path>/lib64/Geant4-V.m.n ..
(V.m.n is the version of Geant4, eg. Geant4-9.6.0)
> make
> make install
The library and header files will be installed on the installation directory of Geant4.
An example of a main program:
#include "G4MPImanager.hh"
#include "G4MPIsession.hh"
int main(int argc,char** argv)
{
// At first, G4MPImanager/G4MPIsession should be created.
G4MPImanager* g4MPI= new G4MPImanager(argc,argv);
// MPI session (G4MPIsession) instead of G4UIterminal
G4MPIsession* session= g4MPI-> GetMPIsession();
// user application setting
G4RunManager* runManager= new G4RunManager();
....
// After user application setting, just start a MPI session.
MPIsession treats both interactive and batch modes.
session-> SessionStart();
// Finally, terminate the program
delete g4MPI;
delete runManager;
}
LAM/MPI users can use "G4tcsh" as an interactive session shell. For other users (Open MPI/MPICH2), plesae use G4csh (default).
In case of OpenMPI, LDLIBRARYPATH for OpenMPI runtime libraries
should be set at run time. Alternatively, you can add this path
to the dynamic linker configuration using ldconfig
.
(needs sys-admin authorization)
lamboot
(LAM) / mpdboot
(MPICH2) / mpd
(Intel).For example,
> mpiexec -n # <your application>
Instead, mpirun
command is more convenient for LAM users.
G4UI commands handling the G4MPI interface are placed in /mpi/.
Command directory path : /mpi/
Guidance :
MPI control commands
Sub-directories :
Commands :
verbose * Set verbose level.
status * Show mpi status.
execute * Execute a macro file. (=/control/execute)
beamOn * Start a parallel run w/ thread.
.beamOn * Start a parallel run w/o thread.
masterWeight * Set weight for master node.
showSeeds * Show seeds of MPI nodes.
setMasterSeed * Set a master seed for the seed generator.
setSeed * Set a seed for a specified node.
While "/run/beamOn" and "/mpi/beamOn" commands invoke beam-on in background, so you can input UI commands even while event processing. Note that drawing tracks in OpenGL with these commands causes a crash. Please use /mpi/.beamOn command instead.
The original "/control/execute" and "/run/beamOn" are overwritten with "/mpi/execute" and "/mpi/beamOn" commands respectively, that are customized for the MPI interface.
There are a couple of examples for Geant4 MPI applications.
In some cases, you need to set some additional environment variables for running examples:
For using ROOT libraries
A simple application.
Configuration:
Features:
An example of dosimetry in a water phantom.
Configuration:
Features: