mercredi 30 mars 2016

MPI transmission of unknown sub-class with boost::mpi::packed_oarchive and packed_iarchive

I am trying to transmit a class of of unknown subclass, but known base class.

I believe this should be possible using boost::serialization, BOOST_CLASS_EXPORT_GUID and boost::mpi, but I'm pretty new to C++ in general

This is the code that I have:

#include <boost/mpi.hpp>
#include <boost/mpi/environment.hpp>
#include <boost/mpi/communicator.hpp>
#include <boost/serialization/string.hpp>
#include <boost/serialization/serialization.hpp>
#include <boost/serialization/export.hpp>
#include <boost/serialization/vector.hpp>
#include <iostream>

namespace mpi = boost::mpi;


class Action {
protected:
    int start_rank;
    std::string greeting;

    Action(std::string greeting) {
        mpi::communicator world;
        this->start_rank = world.rank();
        this->greeting = greeting;
    };

private:

    friend class boost::serialization::access;
    template<class Archive> void serialize(Archive &ar, const unsigned int version) {
        ar & this->start_rank;
        ar & this->greeting;
    };

public:

    Action() = default;

    void invoke() {
        mpi::communicator world;
        std::cout << this->greeting << "! I am process " << world.rank() << " of " << world.size()
            << ". I was created on " << this->start_rank << "." << std::endl;
    };
};


class HelloAction : public Action {

public:
    HelloAction() : Action("Hello") {};

};

class GoodByeAction : public Action {

public:
    GoodByeAction() : Action("Good bye") {};

};

BOOST_CLASS_EXPORT_GUID(Action, "Action");
BOOST_CLASS_EXPORT_GUID(HelloAction, "HelloAction");
BOOST_CLASS_EXPORT_GUID(GoodByeAction, "GoodByeAction");

int main() {
    mpi::environment env;
    mpi::communicator world;

    HelloAction *hello = new HelloAction();
    mpi::broadcast(world, hello, 0);
    hello->invoke();

    GoodByeAction *bye = new GoodByeAction();
    mpi::broadcast(world, bye, 1);
    bye->invoke();

    world.barrier();

    if (world.rank() == 0) {
        std::cout << "sending unknown action classes!" << std::endl;
        HelloAction *yup = new HelloAction();
        boost::mpi::packed_oarchive oar(world);
        oar << yup;
    }
    else {
        std::cout << "receiving unknown action classes!" << std::endl;
        Action *action = NULL;
        boost::mpi::packed_iarchive iar(world);
        iar >> action;
        action->invoke();
    }

    return 0;
}

compiling/running with:

mpic++ -g -std=c++1y hello.cpp -lboost_serialization -lmpi -lboost_mpi
mpiexec -np 2 ./a.out

This seems to run just fine:

Hello! I am process 0 of 2. I was created on 0.
Hello! I am process 1 of 2. I was created on 0.
Good bye! I am process 1 of 2. I was created on 1.
Good bye! I am process 0 of 2. I was created on 1.

... until getting to the "sending/receiving of unknown action classes", where I get runtime errors:

receiving unknown action classes!
sending unknown action classes!
terminate called after throwing an instance of 'boost::exception_detail::clone_impl<boost::exception_detail::error_info_injector<boost::mpi::exception> >'
  what():  MPI_Unpack: MPI_ERR_ARG: invalid argument of some other kind
[machine-name:20194] *** Process received signal ***
[machine-name:20194] Signal: Aborted (6)
[machine-name:20194] Signal code:  (-6)
[machine-name:20194] [ 0] /lib/x86_64-linux-gnu/libc.so.6(+0x352f0) [0x7fa685cc22f0]
[machine-name:20194] [ 1] /lib/x86_64-linux-gnu/libc.so.6(gsignal+0x37) [0x7fa685cc2267]
[machine-name:20194] [ 2] /lib/x86_64-linux-gnu/libc.so.6(abort+0x16a) [0x7fa685cc3eca]
[machine-name:20194] [ 3] /usr/lib/x86_64-linux-gnu/libstdc++.so.6(_ZN9__gnu_cxx27__verbose_terminate_handlerEv+0x16d) [0x7fa6862fdb7d]
[machine-name:20194] [ 4] /usr/lib/x86_64-linux-gnu/libstdc++.so.6(+0x8d9c6) [0x7fa6862fb9c6]
[machine-name:20194] [ 5] /usr/lib/x86_64-linux-gnu/libstdc++.so.6(+0x8da11) [0x7fa6862fba11]
[machine-name:20194] [ 6] /usr/lib/x86_64-linux-gnu/libstdc++.so.6(+0x8dc29) [0x7fa6862fbc29]
[machine-name:20194] [ 7] ./a.out(_ZN5boost15throw_exceptionINS_3mpi9exceptionEEEvRKT_+0x80) [0x41426d]
[machine-name:20194] [ 8] ./a.out() [0x413802]
[machine-name:20194] [15] ./a.out() [0x4306e6]
[machine-name:20194] [16] /usr/lib/x86_64-linux-gnu/libboost_serialization.so.1.58.0(_ZN5boost7archive6detail19basic_iarchive_impl12load_pointerERNS1_14basic_iarchiveERPvPKNS1_25basic_pointer_iserializerEPFS9_RKNS_13serialization18extended_type_infoEE+0x4d) [0x7fa686df5b8d]
[machine-name:20194] [17] ./a.out() [0x41d08d]
[machine-name:20194] [23] ./a.out() [0x40d293]
[machine-name:20194] [24] /lib/x86_64-linux-gnu/libc.so.6(__libc_start_main+0xf0) [0x7fa685cada40]
[machine-name:20194] [25] ./a.out() [0x40cfc9]
[machine-name:20194] *** End of error message ***
--------------------------------------------------------------------------
mpiexec noticed that process rank 1 with PID 20194 on node machine-name exited on signal 6 (Aborted).
--------------------------------------------------------------------------

Questions:

  1. Although the question is tagged with boost, should it be possible to transmit an unknown subclass at all with or without boost? I understand I could have a registration of sorts by string name, and an inversion of control guy to handle creation, but I thought that was the intent of BOOST_CLASS_EXPORT_GUID.
  2. Is there a way to make this work with what I have?
  3. Is there a reasonably easy alternative (not using boost) to make this work with regular ol' MPI?

Aucun commentaire:

Enregistrer un commentaire