[Libmesh-users] MPI problem

[蔡园武 <yua...@gm...>]

Hi, guys,
I have a problem using MPI. The behaviour of my code becomes weird.
The following is part of my code where the problem is:

    // First output mesh and nodal data
    const MeshBase& mesh = es.get_mesh();
    std::cout << '[' << libMesh::processor_id() << "] "
              << "writing es..." << std::endl;
    GMVIO(mesh).write_equation_systems(file_name, es);

    // Read in gmv file, and do something
    std::cout << '[' << libMesh::processor_id() << "] "
              << "open file " << file_name << std::endl;
    std::ifstream fin(file_name.c_str());
    if (!fin) {
        std::cerr << '[' << libMesh::processor_id() << "] "
                  << "ERROR: Can't open file " << file_name
                  << std::endl;
        libmesh_error();
    }


And the output of this part:

[0] writing es...
[1] ERROR: Can't open file Iter_0.gmv
[1] src/output.C, line 127, compiled Aug 27 2012 at 01:52:52
terminate called after throwing an instance of 'libMesh::LogicError'
  what():  Error in libMesh internal logic
[ubuntu:05720] *** Process received signal ***
[ubuntu:05720] Signal: Aborted (6)
[ubuntu:05720] Signal code:  (-6)
[ubuntu:05720] [ 0] [0x8f240c]
[ubuntu:05720] [ 1] [0x8f2416]
[ubuntu:05720] [ 2] /lib/i386-linux-gnu/libc.so.6(gsignal+0x4f) [0x1edfc8f]
[ubuntu:05720] [ 3] /lib/i386-linux-gnu/libc.so.6(abort+0x175) [0x1ee32b5]
[ubuntu:05720] [ 4]
/usr/lib/i386-linux-gnu/libstdc++.so.6(_ZN9__gnu_cxx27__verbose_terminate_handlerEv+0x14d)
[0x6ee94ed]
[ubuntu:05720] [ 5]
/home/cyw/libmesh-0.7.3.1/libmesh/lib/i686-pc-linux-gnu_opt/libmesh.so(_ZN7libMesh25libmesh_terminate_handlerEv+0x17)
[0xda4087]
[ubuntu:05720] [ 6] /usr/lib/i386-linux-gnu/libstdc++.so.6(+0xaf283) [0x6ee7283]
[ubuntu:05720] [ 7] /usr/lib/i386-linux-gnu/libstdc++.so.6(+0xaf2bf) [0x6ee72bf]
[ubuntu:05720] [ 8] /usr/lib/i386-linux-gnu/libstdc++.so.6(+0xaf40e) [0x6ee740e]
[ubuntu:05720] [ 9]
./main-opt(_Z10gmv_outputRKSsRN7libMesh15EquationSystemsERKb+0x3033)
[0x8147e33]
[ubuntu:05720] [10]
./main-opt(_Z21topology_optimizationR6GetPot+0x43d7) [0x813d8e7]
[ubuntu:05720] [11] ./main-opt(main+0xc32) [0x8062c12]
[ubuntu:05720] [12]
/lib/i386-linux-gnu/libc.so.6(__libc_start_main+0xf3) [0x1ecb113]
[ubuntu:05720] [13] ./main-opt() [0x8063411]
[ubuntu:05720] *** End of error message ***
[0] open file Iter_0.gmv


It seems that the processor_id 0 is writing equation_systems to file
"Iter_0.gmv", and at the same time, processor_id 1 is trying to open
the file "Iter_0.gmv". Is it correct?
I don't know much about MPI. Could someone explain this error, and how
to solve it?
Thanks!
-- 
Cai Yuanwu  蔡园武
Dept. of Engineering Mechanics,
Dalian University of Technology,
Dalian 116024, China