Segmentation fault in MPI_Test() when using singleton/wrapper classes - c++

Question

During my work writing a C++ wrapper for MPI I ran into a segmentation fault in MPI_Test(), the reason of which I can't figure out.
The following code is a minimal crashing example, to be compiled and run with mpic++ -std=c++11 -g -o test test.cpp && ./test:
#include <stdlib.h>
#include <stdio.h>
#include <memory>
#include <mpi.h>
class Environment {
public:
static Environment &getInstance() {
static Environment instance;
return instance;
}
static bool initialized() {
int ini;
MPI_Initialized(&ini);
return ini != 0;
}
static bool finalized() {
int fin;
MPI_Finalized(&fin);
return fin != 0;
}
private:
Environment() {
if(!initialized()) {
MPI_Init(NULL, NULL);
_initialized = true;
}
}
~Environment() {
if(!_initialized)
return;
if(finalized())
return;
MPI_Finalize();
}
bool _initialized{false};
public:
Environment(Environment const &) = delete;
void operator=(Environment const &) = delete;
};
class Status {
private:
std::shared_ptr<MPI_Status> _mpi_status;
MPI_Datatype _mpi_type;
};
class Request {
private:
std::shared_ptr<MPI_Request> _request;
int _flag;
Status _status;
};
int main() {
auto &m = Environment::getInstance();
MPI_Request r;
MPI_Status s;
int a;
MPI_Test(&r, &a, &s);
Request r2;
printf("b\n");
}
Basically, the Environment class is a singleton wrapper around MPI_Init and MPI_Finalize. When the program exits, MPI will be finalized and the first time the class is instantiated, MPI_Init is called. Then I do some MPI stuff in the main() function, involving some other simple wrapper objects.
The code above crashes (on my machine, OpenMPI & Linux). However, it works when I
comment any of the private members of Request or Status (even int _flag;)
comment the last line, printf("b\n");
Replace auto &m = Environment::getInstance(); with MPI_Init().
There doesn't seem to be a connection between these points and I have no clue where to look for the segmentation fault.
The stack trace is:
[pc13090:05978] *** Process received signal ***
[pc13090:05978] Signal: Segmentation fault (11)
[pc13090:05978] Signal code: Address not mapped (1)
[pc13090:05978] Failing at address: 0x61
[pc13090:05978] [ 0] /usr/lib/libpthread.so.0(+0x11dd0)[0x7fa9cf818dd0]
[pc13090:05978] [ 1] /usr/lib/openmpi/libmpi.so.40(ompi_request_default_test+0x16)[0x7fa9d0357326]
[pc13090:05978] [ 2] /usr/lib/openmpi/libmpi.so.40(MPI_Test+0x31)[0x7fa9d03970b1]
[pc13090:05978] [ 3] ./test(+0xb7ae)[0x55713d1aa7ae]
[pc13090:05978] [ 4] /usr/lib/libc.so.6(__libc_start_main+0xea)[0x7fa9cf470f4a]
[pc13090:05978] [ 5] ./test(+0xb5ea)[0x55713d1aa5ea]
[pc13090:05978] *** End of error message ***
-------------------------------------------------------
Primary job terminated normally, but 1 process returned
a non-zero exit code. Per user-direction, the job has been aborted.
-------------------------------------------------------
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mpirun noticed that process rank 0 with PID 0 on node pc13090 exited on signal 11 (Segmentation fault).
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