使用 pybind11 共享 MPI 通信器
Sharing an MPI communicator using pybind11
假设我已经围绕 MPI 通信器创建了一个包装器:
class Communicator {
public:
Communicator() : comm(MPI_COMM_WORLD) {}
Communicator(int const color, int const key) {
MPI_Comm_split(MPI_COMM_WORLD, color, key, &comm);
}
Communicator(MPI_Comm comm) : comm(comm) {}
MPI_Comm GetComm() const { return comm; }
private:
MPI_Comm comm;
};
我想使用 pybind11 围绕这个对象创建一个 python 包装器,看起来像这样:
void CommunicatorWrapper(pybind11::module &m) {
py::class_<Communicator, std::shared_ptr<Communicator> > commWrap(m, "Communicator");
commWrap.def(py::init( []() { return new Communicator(); } ));
commWrap.def(py::init( [](int const color, int const key) { return new Communicator(color, key); } ));
commWrap.def(py::init( [](MPI_Comm comm) { return new Communicator(comm); } ));
commWrap.def("GetComm", &Communicator::GetComm);
}
但是,我想要 python 看到的 MPI_Comm
类型 mpi4py.MPI.Comm
。这可能吗?如果是,怎么做?
以上(天真的)实现导致以下行为:
comm = Communicator(MPI.COMM_WORLD)
错误:
TypeError: __init__(): incompatible constructor arguments. The following argument types are supported:
1. Communicator()
2. Communicator(arg0: int, arg1: int)
3. Communicator(arg0: int)
和
comm = Communicator()
print(comm.GetComm())
打印 -2080374784
。鉴于 MPI_Comm
是什么,这种行为是有道理的,但显然不是我需要的功能。
我通过将包装器更改为
解决了这个问题
#include <mpi4py/mpi4py.h>
pybind11::handle CallGetComm(Communicator *comm) {
const int rc = import_mpi4py();
return pybind11::handle(PyMPIComm_New(comm->GetComm()));;
}
void CommunicatorWrapper(pybind11::module &m) {
py::class_<Communicator, std::shared_ptr<Communicator> > commWrap(m, "Communicator");
commWrap.def(py::init( []() { return new Communicator(); } ));
commWrap.def(py::init( [](int const color, int const key) { return new Communicator(color, key); } ));
commWrap.def(py::init( [](pybind11::handle const& comm) {
const int rc = import_mpi4py();
assert(rc==0);
return new Communicator(*PyMPIComm_Get(comm.ptr()));
} ));
commWrap.def("GetComm", &CallGetComm);
}
假设我已经围绕 MPI 通信器创建了一个包装器:
class Communicator {
public:
Communicator() : comm(MPI_COMM_WORLD) {}
Communicator(int const color, int const key) {
MPI_Comm_split(MPI_COMM_WORLD, color, key, &comm);
}
Communicator(MPI_Comm comm) : comm(comm) {}
MPI_Comm GetComm() const { return comm; }
private:
MPI_Comm comm;
};
我想使用 pybind11 围绕这个对象创建一个 python 包装器,看起来像这样:
void CommunicatorWrapper(pybind11::module &m) {
py::class_<Communicator, std::shared_ptr<Communicator> > commWrap(m, "Communicator");
commWrap.def(py::init( []() { return new Communicator(); } ));
commWrap.def(py::init( [](int const color, int const key) { return new Communicator(color, key); } ));
commWrap.def(py::init( [](MPI_Comm comm) { return new Communicator(comm); } ));
commWrap.def("GetComm", &Communicator::GetComm);
}
但是,我想要 python 看到的 MPI_Comm
类型 mpi4py.MPI.Comm
。这可能吗?如果是,怎么做?
以上(天真的)实现导致以下行为:
comm = Communicator(MPI.COMM_WORLD)
错误:
TypeError: __init__(): incompatible constructor arguments. The following argument types are supported:
1. Communicator()
2. Communicator(arg0: int, arg1: int)
3. Communicator(arg0: int)
和
comm = Communicator()
print(comm.GetComm())
打印 -2080374784
。鉴于 MPI_Comm
是什么,这种行为是有道理的,但显然不是我需要的功能。
我通过将包装器更改为
解决了这个问题#include <mpi4py/mpi4py.h>
pybind11::handle CallGetComm(Communicator *comm) {
const int rc = import_mpi4py();
return pybind11::handle(PyMPIComm_New(comm->GetComm()));;
}
void CommunicatorWrapper(pybind11::module &m) {
py::class_<Communicator, std::shared_ptr<Communicator> > commWrap(m, "Communicator");
commWrap.def(py::init( []() { return new Communicator(); } ));
commWrap.def(py::init( [](int const color, int const key) { return new Communicator(color, key); } ));
commWrap.def(py::init( [](pybind11::handle const& comm) {
const int rc = import_mpi4py();
assert(rc==0);
return new Communicator(*PyMPIComm_Get(comm.ptr()));
} ));
commWrap.def("GetComm", &CallGetComm);
}