Re: [Boost-users] [Boost.MPI] question about serializingcustomobject

Subject: Re: [Boost-users] [Boost.MPI] question about serializingcustomobject
From: Cristobal Navarro (axischire_at_[hidden])
Date: 2010-08-26 19:20:57

ok now it worked!!

i kept the object pointer method, started to enable/disable diferent
serialization atributes of class "Edge" and i found something inexplicable.
This is the original "Edge Class" when program crashed.

#CLASS EDGE
class Edge{
    private:
        friend class boost::serialization::access;
        template<class Archive>
        void serialize(Archive & ar, const unsigned int version){
            ar & sp;
            ar & dead;
            ar & n1;
            ar & n2;
            ar & id;
        }
    public:
        int n1;
        int n2;
        int id;
        bool sp;
        bool dead;
        //plus some methods, constructors, etc
};

now this is "Edge" Class with "bool dead" removed.
#EDGE 2.0 not dead
class Edge{

    private:
        friend class boost::serialization::access;
        template<class Archive>
        void serialize(Archive & ar, const unsigned int version){
            ar & n1;
            ar & n2;
            ar & id;
            ar & sp;
        }

    public:
        int n1;
        int n2;
        int id;
        bool sp;
};

i dont know why removing that bool "dead", program worked, what influence
did that have on Boost?

On Thu, Aug 26, 2010 at 6:59 PM, Cristobal Navarro <axischire_at_[hidden]>wrote:

>
>> Hmmm- what surrounds this?
>>
>
> -> there is more code part of an algorithm, but nothing important for the
> example embedded.
>
>>
>> try
>>
>> {
>>    const class Lattice lat ...
>>     ...
>>     ar << lat
>> }
>>
>> that might work better.
>>
>> Robert Ramey
>>
> thanks Robert, let me tell you about lat just in case i missed to point
> something
> lat was created this way
>  Lattice *lat = new Lattice("filename");
> i thought that pointers passed to archive wasnt possible, thats why i did
> "ao << *(this->lat);", and it actually worked when i removed edges. however
> i also tried what yo suggested, and it also works without "edges", but
> otherwise i get the same error.
> this is updated code if i use class pointers
>
>                 printf("serializing to binlat.x...\n");
>                 //!file mode
>                 /*
>                 std::ofstream ofs("binlat.x", ios::binary);
>                 boost::archive::binary_oarchive oa(ofs);
>                 */
>                 oa << lat; //lat was created earlier at some point of the
> program "Lattice *lat = new Lattice("filename")"
>                 ofs.close();
>                 lat->print(); //check what lattice im serializing
>                 //!Deserialization - read file  binlat.x and reconstruct
>                 printf("reconstructing serialized binlat.x...\n");
>                 Lattice *nl;
>                 std::ifstream ifs("binlat.x", ios::binary);
>                 boost::archive::binary_iarchive ia(ifs);
>                 //!deserialize object
>                 ia >> nl;
>                 ifs.close();
>                 nl->print();
>
> i had to change the receiving lattice to a class pointer too. in the end,
> it also throws the same error when "edges" map is included on the
> serialization.
> i will keep trying different ideas to find the problem, in the meanwhile
> any help is welcome.
> by considering that when i remove "edges" from the serialization of Lattice
> object it works, i suspect the problem comes from "edges" map or maybe from
> the "Edge" class at a particular atribute.
>
>
>>
>>
>> >
>> >
>> > i get bad errors when deserializing, complaining about a bool and
>> > char.
>> > serializing to binlat.x...
>> > Lattice::print().....START
>> > Nodes=2   Edges= 1
>> > Node[0] sp=1 ext=1
>> > Linked to edge 2 (Node 3 or 0 )
>> > Node[3] sp=1 ext=2
>> > Linked to edge 2 (Node 3 or 0 )
>> > Lattice::print().....END
>> > [enter]
>> > reconstructing swerialized binlat.x...
>> > [enter]
>> > plattice:
>> > /usr/local/include/boost/archive/basic_binary_iprimitive.hpp:98: void
>> > boost::archive::basic_binary_iprimitive<Archive, Elem,
>> > Tr>::load(bool&) [with Archive = boost::archive::binary_iarchive,
>> > Elem = char, Tr = std::char_traits<char>]: Assertion `0 == i || 1 ==
>> > i' failed.
>> > [lenovo00:29384] *** Process received signal ***
>> > [lenovo00:29384] Signal: Aborted (6)
>> > [lenovo00:29384] Signal code:  (-6)
>> > [lenovo00:29384] [ 0] [0xfea410]
>> > [lenovo00:29384] [ 1] /lib/tls/i686/cmov/libc.so.6(abort+0x182)
>> > [0xd41a82]
>> > [lenovo00:29384] [ 2]
>> > /lib/tls/i686/cmov/libc.so.6(__assert_fail+0xf8) [0xd37718]
>> > [lenovo00:29384] [ 3]
>> > ..
>> > ..
>> > *** End of error message ***
>> >
>> >
>> > i started debugging, and realized that the problem is completely gone
>> > when i remove "edges" from the serialization members of "Lattice"
>> > object.
>> > its weird, because "edge" is a map of <int, Edge> and much simplier
>> > than "nodes" which does work. obviously i cannot continue without
>> > edges, so i need to fix it somehow, but i dont understand the error
>> > related to edges, maybe is something im not seeing.
>> >
>> >
>> > dont get distracted by the messy code, i had to edit it a little to
>> > focus on the case.
>> > regards
>> > Cristobal
>> >
>> >
>> >
>> >
>> >
>> >
>> > On Thu, Aug 26, 2010 at 4:35 PM, Robert Ramey <ramey_at_[hidden]> wrote:
>> >
>> >> Change the "would" into "is": it is possible to mix Boost.MPI with
>> >> Boost.Serialization. Any objext that can be serialized can be sent by
>> >> Boost.MPI. This was actually the basic idea behind Boost.MPI, to use
>> >> Boost.Serialization to pack and unpack MPI buffers, or to create
>> >> custom MPI datatypes.
>> >
>> > On thing that I never understood is why you need MPI data types at
>> > all.
>> > If one is serializing (packing) to a binary array, and sending that,
>> > what
>> > hae MPI data types have to do with it.
>> >
>> > If one were using heterogenious machines, I could understand the
>> > usage of MPI types. But as I understand it, the MPI serialization
>> > presumes
>> > that the machines are binary compatible.  So I'm just not seeing this.
>> >
>> > Robert Ramey
>> >
>> >
>> >
>> > _______________________________________________
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>> > Boost-users_at_[hidden]
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>> >
>> >
>> >
>> >
>> >
>> >
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