mirror of https://github.com/QMCPACK/qmcpack.git
48 lines
1.3 KiB
C++
48 lines
1.3 KiB
C++
#if COMPILATION_INSTRUCTIONS
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mpicxx -O3 -std=c++14 -Wfatal-errors $0 -o $0x.x && time mpirun -np 4 $0x.x $@ && rm -f $0x.x; exit
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#endif
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#include "alf/boost/mpi3/main.hpp"
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#include "alf/boost/mpi3/version.hpp"
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#include<iostream>
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namespace mpi3 = boost::mpi3;
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using std::cout;
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int mpi3::main(int argc, char* argv[], boost::mpi3::communicator& world){
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if(world.size() % 2 != 0){
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if(world.root()) cout << "Quitting. Need an even number of tasks: numtasks = " << world.size() << "\n";
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}else{
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int message = -1;
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if(world.root()) cout << "MASTER: number of mpi tasks is " << world.size() << "\n";
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if(world.rank() < world.size()/2){
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int partner = world.rank() + world.size()/2;
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int rank = world.rank();
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world.send_value(rank, partner);
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world.receive_value(message, partner);
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}else if(world.rank() >= world.size()/2){
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int partner = world.rank() - world.size()/2;
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world.receive_value(message, partner);
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int rank = world.rank();
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world.send_value(rank, partner);
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}
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cout << "Task " << world.rank() << " is partner with " << message << "\n";
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}
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if(world.rank()==0){
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std::vector<double> code = {1.,2.,3.,4.};
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world.send_n(code.begin(), 4, 1);
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}
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if(world.rank()==1){
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std::vector<double> code(4);
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world.receive_n(code.begin(), 4, 0);
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assert(( code == std::vector<double>{1.,2.,3.,4.} ));
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}
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return 0;
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}
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