file Utils/mpiwrapper.hpp
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Detailed Description
Author:
- Ben Farmer (benjamin.farmer@fysik.su.se)
- Pat Scott (p.scott@imperial.ac.uk)
Date:
- 2015 Apr
- 2015 Jun
A simple C++ wrapper for the MPI C bindings. It is by no means comprehensive, and is just intended to simplify some MPI commands within Gambit.
Extend as needed.
Note: Some C++ bindings already exist, but it appears that they are deprecated in really new versions of the MPI standard, and don’t offer functionality over the C bindings anyway. I have nevertheless mirrored the names of some of the deprecated C++ bindings, in case it helps some people who were used to them.
There is also boost/mpi, but it is a compiled library and we have been avoiding those.
You can remove the error handlers if you want these wrappers to be independent of GAMBIT.
Authors (add name and date if you modify):
Source code
// GAMBIT: Global and Modular BSM Inference Tool
// *********************************************
/// \file
///
/// A simple C++ wrapper for the MPI C bindings.
/// It is by no means comprehensive, and is just
/// intended to simplify some MPI commands within
/// Gambit.
///
/// Extend as needed.
///
/// Note: Some C++ bindings already exist, but
/// it appears that they are deprecated in really
/// new versions of the MPI standard, and don't
/// offer functionality over the C bindings
/// anyway. I have nevertheless mirrored the names
/// of some of the deprecated C++ bindings, in
/// case it helps some people who were used to
/// them.
///
/// There is also boost/mpi, but it is a compiled
/// library and we have been avoiding those.
///
/// You can remove the error handlers if you want
/// these wrappers to be independent of GAMBIT.
///
/// *********************************************
///
/// Authors (add name and date if you modify):
///
/// \author Ben Farmer
/// (benjamin.farmer@fysik.su.se)
/// \date 2015 Apr
///
/// \author Pat Scott
/// (p.scott@imperial.ac.uk)
/// \date 2015 Jun
///
/// *********************************************
// The WITH_MPI macro determines whether MPI is used or not.
// It is defined at compile time by cmake with -DWITH_MPI.
// The contents of this file are ignored if MPI is disabled.
#ifdef WITH_MPI
#ifndef __mpiwrapper_hpp__
#define __mpiwrapper_hpp__
#include <sstream>
#include <iostream>
#include <type_traits>
#include <chrono>
#include "gambit/Utils/begin_ignore_warnings_mpi.hpp"
#include <mpi.h>
#include "gambit/Utils/end_ignore_warnings.hpp"
#include <boost/utility/enable_if.hpp>
#include "gambit/Utils/standalone_error_handlers.hpp"
#include "gambit/Utils/local_info.hpp"
#include "gambit/Utils/util_macros.hpp"
// I wanted to keep the GAMBIT logger separate from this code so that it
// would be more streamlined for using elsewhere. But the logger is very
// useful for debugging, so this preprocessor flag can be used to turn
// it on and off
// Though it might already be included via the error handlers anyway.
#define USE_GAMBIT_LOGGER
#ifdef USE_GAMBIT_LOGGER
#include "gambit/Logs/logger.hpp"
#define LOGGER logger() << LogTags::utils << LogTags::info
#else
#define LOGGER std::cerr
#define EOM std::endl
#endif
/// Provide template specialisation of get_mpi_data_type only if the requested type hasn't been used to define one already.
#define SPECIALISE_MPI_DATA_TYPE_IF_NEEDED(TYPEDEFD_TYPE, RETURN_MPI_TYPE) \
template<typename T> \
struct get_mpi_data_type<T, typename boost::enable_if_c< std::is_same<T, TYPEDEFD_TYPE>::value && \
!std::is_same<char, TYPEDEFD_TYPE>::value && \
!std::is_same<short, TYPEDEFD_TYPE>::value && \
!std::is_same<int, TYPEDEFD_TYPE>::value && \
!std::is_same<long, TYPEDEFD_TYPE>::value && \
!std::is_same<long long, TYPEDEFD_TYPE>::value && \
!std::is_same<unsigned char, TYPEDEFD_TYPE>::value && \
!std::is_same<unsigned short, TYPEDEFD_TYPE>::value && \
!std::is_same<unsigned int, TYPEDEFD_TYPE>::value && \
!std::is_same<unsigned long, TYPEDEFD_TYPE>::value && \
!std::is_same<unsigned long long, TYPEDEFD_TYPE>::value && \
!std::is_same<float, TYPEDEFD_TYPE>::value && \
!std::is_same<double, TYPEDEFD_TYPE>::value && \
!std::is_same<long double, TYPEDEFD_TYPE>::value && \
!std::is_same<bool, TYPEDEFD_TYPE>::value>::type > \
{ \
static MPI_Datatype type() { return RETURN_MPI_TYPE; } \
}; \
/// Trigger debugging output when messages sent/recvd
//#define MPI_MSG_DEBUG
namespace Gambit
{
namespace GMPI
{
/// Mapping from (basic) C++ types to MPI datatypes
/// Based on of "get_hdf5_data_type" in hdf5tools.hpp
/// Base template is left undefined in order to raise
/// a compile error if specialisation doesn't exist.
template<typename T, typename Enable=void>
struct get_mpi_data_type;
/// Overload to work with arrays
template<typename T, size_t SIZE>
struct get_mpi_data_type<T[SIZE]> { static MPI_Datatype type() { return get_mpi_data_type<T>::type(); } };
/// True types
/// @{
template<> struct get_mpi_data_type<char> { static MPI_Datatype type() { return MPI_CHAR; } };
template<> struct get_mpi_data_type<short> { static MPI_Datatype type() { return MPI_SHORT; } };
template<> struct get_mpi_data_type<int> { static MPI_Datatype type() { return MPI_INT; } };
template<> struct get_mpi_data_type<long> { static MPI_Datatype type() { return MPI_LONG; } };
template<> struct get_mpi_data_type<long long> { static MPI_Datatype type() { return MPI_LONG_LONG; } };
template<> struct get_mpi_data_type<unsigned char> { static MPI_Datatype type() { return MPI_UNSIGNED_CHAR; } };
template<> struct get_mpi_data_type<unsigned short> { static MPI_Datatype type() { return MPI_UNSIGNED_SHORT; } };
template<> struct get_mpi_data_type<unsigned int> { static MPI_Datatype type() { return MPI_UNSIGNED; } };
template<> struct get_mpi_data_type<unsigned long> { static MPI_Datatype type() { return MPI_UNSIGNED_LONG; } };
template<> struct get_mpi_data_type<unsigned long long>{ static MPI_Datatype type() { return MPI_UNSIGNED_LONG_LONG; } };
template<> struct get_mpi_data_type<float> { static MPI_Datatype type() { return MPI_FLOAT; } };
template<> struct get_mpi_data_type<double> { static MPI_Datatype type() { return MPI_DOUBLE; } };
template<> struct get_mpi_data_type<long double> { static MPI_Datatype type() { return MPI_LONG_DOUBLE; } };
/// @}
/// Typedef'd types; enabled only where they differ from the true types, and where the relevant constants have been
/// defined in the linked MPI implementation.
/// @{
#ifdef MPI_INT8_T
SPECIALISE_MPI_DATA_TYPE_IF_NEEDED(int8_t, MPI_INT8_T )
#endif
#ifdef MPI_UINT8_T
SPECIALISE_MPI_DATA_TYPE_IF_NEEDED(uint8_t, MPI_UINT8_T )
#endif
#ifdef MPI_INT16_T
SPECIALISE_MPI_DATA_TYPE_IF_NEEDED(int16_t, MPI_INT16_T )
#endif
#ifdef MPI_UINT16_T
SPECIALISE_MPI_DATA_TYPE_IF_NEEDED(uint16_t, MPI_UINT16_T)
#endif
#ifdef MPI_INT32_T
SPECIALISE_MPI_DATA_TYPE_IF_NEEDED(int32_t, MPI_INT32_T )
#endif
#ifdef MPI_UINT32_T
SPECIALISE_MPI_DATA_TYPE_IF_NEEDED(uint32_t, MPI_UINT32_T)
#endif
#ifdef MPI_INT64_T
SPECIALISE_MPI_DATA_TYPE_IF_NEEDED(int64_t, MPI_INT64_T )
#endif
#ifdef MPI_UINT64_T
SPECIALISE_MPI_DATA_TYPE_IF_NEEDED(uint64_t, MPI_UINT64_T)
#endif
/// @}
/// Main "Communicator" class
class EXPORT_SYMBOLS Comm
{
public:
/// Default Constructor; attaches to MPI_COMM_WORLD
Comm();
/// Constructor which copies existing communicator into boundcomm
Comm(const MPI_Comm& comm, const std::string& name);
/// Constructor which creates a communicator gruop from WORLD containing
/// only the specified processes
Comm(std::vector<int> processes, const std::string& name);
/// Destructor
~Comm();
/// Create a new communicator group for the specified processes
Comm spawn_new(const std::vector<int>& processes, const std::string& name);
/// As name
void check_for_undelivered_messages();
/// Duplicate existing communicator
/// (NOTE, this is a collective operation on all procceses)
void dup(const MPI_Comm& comm, const std::string& newname);
/// Get total number of MPI tasks in this communicator group
int Get_size() const;
/// Get "rank" (ID number) of current task in this communicator group
int Get_rank() const;
/// Get name of communicator group (for error messages)
std::string Get_name() const;
/// Prevent further executation until all members of the bound communicator group enter the call
void Barrier()
{
#ifdef MPI_MSG_DEBUG
std::cout<<"rank "<<Get_rank()<<": Barrier() called"<<std::endl;
#endif
int errflag;
errflag = MPI_Barrier(boundcomm);
if(errflag!=0) {
std::ostringstream errmsg;
errmsg << "Error performing MPI_Barrier! Received error flag: "<<errflag;
utils_error().raise(LOCAL_INFO, errmsg.str());
}
#ifdef MPI_MSG_DEBUG
std::cout<<"rank "<<Get_rank()<<": Barrier() passed"<<std::endl;
#endif
}
/// Blocking receive
/// void* buf - memory address in which to store received message
/// int count - number of elements in message
/// MPI_Datatype datatype - datatype of each message element
/// int source - rank of sending (receiving?) process
/// int tag - message tag
/// MPI_status* status - struct containing data about the received message
/// Returns:
/// MPI_status - struct containing data about the received message
void Recv(void *buf /*out*/, int count, MPI_Datatype datatype,
int source, int tag,
MPI_Status *in_status=NULL /*out*/)
{
#ifdef MPI_MSG_DEBUG
std::cout<<"rank "<<Get_rank()<<": Recv() called (count="<<count<<", source="<<source<<", tag="<<tag<<")"<<std::endl;
#endif
int errflag;
errflag = MPI_Recv(buf, count, datatype, source, tag, boundcomm, in_status == NULL ? MPI_STATUS_IGNORE : in_status);
if(errflag!=0)
{
std::ostringstream errmsg;
errmsg << "Error performing MPI_Recv! Received error flag: "<<errflag;
utils_error().raise(LOCAL_INFO, errmsg.str());
}
#ifdef MPI_MSG_DEBUG
std::cout<<"rank "<<Get_rank()<<": Recv() finished "<<std::endl;
#endif
}
/// Templated blocking receive to automatically determine types
template<class T>
void Recv(T *buf /*out*/, int count,
int source, int tag,
MPI_Status *status=NULL /*out*/)
{
static const MPI_Datatype datatype = get_mpi_data_type<T>::type();
Recv(buf, count, datatype, source, tag, status);
}
/// Blocking send
void Send(void *buf, int count, MPI_Datatype datatype,
int destination, int tag)
{
#ifdef MPI_MSG_DEBUG
std::cout<<"rank "<<Get_rank()<<": Send() called (count="<<count<<", destination="<<destination<<", tag="<<tag<<")"<<std::endl;
#endif
int errflag;
errflag = MPI_Send(buf, count, datatype, destination, tag, boundcomm);
if(errflag!=0) {
std::ostringstream errmsg;
errmsg << "Error performing MPI_Send! Received error flag: "<<errflag;
utils_error().raise(LOCAL_INFO, errmsg.str());
}
#ifdef MPI_MSG_DEBUG
std::cout<<"rank "<<Get_rank()<<": Send() finished"<<std::endl;
#endif
}
/// Blocking synchronous send (will not return until matching Recv is posted)
void Ssend(void *buf, int count, MPI_Datatype datatype,
int destination, int tag)
{
#ifdef MPI_MSG_DEBUG
std::cout<<"rank "<<Get_rank()<<": Ssend() called (count="<<count<<", destination="<<destination<<", tag="<<tag<<")"<<std::endl;
#endif
int errflag;
errflag = MPI_Ssend(buf, count, datatype, destination, tag, boundcomm);
if(errflag!=0) {
std::ostringstream errmsg;
errmsg << "Error performing MPI_Ssend! Received error flag: "<<errflag;
utils_error().raise(LOCAL_INFO, errmsg.str());
}
#ifdef MPI_MSG_DEBUG
std::cout<<"rank "<<Get_rank()<<": Ssend() finished"<<std::endl;
#endif
}
/// Templated blocking send
template<class T>
void Send(T *buf, int count,
int destination, int tag)
{
static const MPI_Datatype datatype = get_mpi_data_type<T>::type();
Send(buf, count, datatype, destination, tag);
}
/// Templated blocking synchronous send
template<class T>
void Ssend(T *buf, int count,
int destination, int tag)
{
static const MPI_Datatype datatype = get_mpi_data_type<T>::type();
Ssend(buf, count, datatype, destination, tag);
}
/// Non-blocking send
void Isend(void *buf, int count, MPI_Datatype datatype,
int destination, int tag,
MPI_Request *request /*out*/)
{
#ifdef MPI_MSG_DEBUG
std::cerr<<"rank "<<Get_rank()<<": Isend() called (count="<<count<<", destination="<<destination<<", tag="<<tag<<")"<<std::endl;
#endif
int errflag;
errflag = MPI_Isend(buf, count, datatype, destination, tag, boundcomm, request);
if(errflag!=0) {
std::ostringstream errmsg;
errmsg << "Error performing MPI_Isend! Received error flag: "<<errflag;
utils_error().raise(LOCAL_INFO, errmsg.str());
}
}
/// Templated Non-blocking send
template<class T>
void Isend(T *buf, int count,
int destination, int tag,
MPI_Request *request /*out*/)
{
static const MPI_Datatype datatype = get_mpi_data_type<T>::type();
Isend(buf, count, datatype, destination, tag, request);
}
/// Blocking wait for e.g. Isend to complete
void Wait(MPI_Request *request)
{
MPI_Status status;
int errflag = MPI_Wait(request, &status);
if(errflag!=0) {
std::ostringstream errmsg;
errmsg << "Error performing MPI_Wait! Received error flag: "<<errflag;
utils_error().raise(LOCAL_INFO, errmsg.str());
}
}
// Non-blocking probe for messages waiting to be delivered
bool Iprobe(int source, int tag, MPI_Status* in_status=NULL /*out*/)
{
//#ifdef MPI_MSG_DEBUG
//std::cout<<"rank "<<Get_rank()<<": Iprobe() called (source="<<source<<", tag="<<tag<<")"<<std::endl;
//#endif
int errflag;
int you_have_mail; // C does not have a bool type...
MPI_Status def_status;
MPI_Status* status;
if(in_status!=NULL) {
status = in_status;
} else {
status = &def_status;
}
//MPI_Iprobe(source, 1, boundcomm, &you_have_mail, status);
errflag = MPI_Iprobe(source, tag, boundcomm, &you_have_mail, status);
if(errflag!=0) {
std::ostringstream errmsg;
errmsg << "Error performing MPI_Iprobe! Received error flag: "<<errflag;
utils_error().raise(LOCAL_INFO, errmsg.str());
}
#ifdef MPI_MSG_DEBUG
if(you_have_mail!=0) {
std::cerr<<"rank "<<Get_rank()<<": Iprobe: Message waiting from process "<<status->MPI_SOURCE<<std::endl;
}
#endif
return (you_have_mail != 0);
}
// Blocking probe for a message. Doesn't return until matching message found.
// No point having default NULL status this time, because the only reason to
// use this function is to inspect the message status.
void Probe(int source, int tag, MPI_Status* status)
{
int errflag;
errflag = MPI_Probe(source, tag, boundcomm, status);
if(errflag!=0) {
std::ostringstream errmsg;
errmsg << "Error performing MPI_Probe! Received error flag: "<<errflag;
utils_error().raise(LOCAL_INFO, errmsg.str());
}
}
// Perform an Isend to all other processes
// (using templated non-blocking send repeatedly)
template<class T>
void IsendToAll(T *buf, int count, int tag,
MPI_Request *in_req=NULL /*out*/)
{
MPI_Request def_req;
MPI_Request* req;
if(in_req!=NULL) {
req = in_req;
} else {
req = &def_req;
}
int rank = Get_rank();
int size = Get_size();
for(int i=0; i<size; i++)
{
if(i!=rank) Isend(buf, count, i, tag, req);
}
}
template <typename T>
void Bcast (std::vector<T>& buffer, int count, int root)
{
static const MPI_Datatype datatype = get_mpi_data_type<T>::type();
MPI_Bcast (&buffer[0], count, datatype, root, boundcomm);
}
template<typename T>
void Scatter (std::vector<T> &sendbuf, T &recvbuf, int root)
{
static const MPI_Datatype datatype = get_mpi_data_type<T>::type();
MPI_Scatter (&sendbuf[0], 1, datatype, &recvbuf, 1, datatype, root, boundcomm);
}
template<typename T>
void Allreduce (T &sendbuf, T &recvbuf, MPI_Op op)
{
static const MPI_Datatype datatype = get_mpi_data_type<T>::type();
MPI_Allreduce (&sendbuf, &recvbuf, 1, datatype, op, boundcomm);
}
template<typename T>
void Gather(std::vector<T> &sendbuf, std::vector<T> &recvbuf, int root)
{
static const MPI_Datatype datatype = get_mpi_data_type<T>::type();
int sendcount = sendbuf.size();
int recvcount = sendbuf.size();
//std::cerr<<"rank "<<Get_rank()<<": Gather pars: sendcount="<<sendcount<<std::endl;
if(Get_rank()==0)
{
if(recvbuf.size()<sendbuf.size()*Get_size())
{
std::ostringstream errmsg;
errmsg << "Error performing Gather! Recv buffer is not big enough to fit the expected data! We expect "<<Get_size()<<" messages of count "<<recvcount<<", (total size="<<recvcount*Get_size()<<") but the recv buffer only has size "<<recvbuf.size()<<"!";
utils_error().raise(LOCAL_INFO, errmsg.str());
}
}
int errflag = MPI_Gather(&sendbuf[0], sendcount, datatype,
&recvbuf[0], recvcount, datatype,
root, boundcomm);
if(errflag!=0) {
std::ostringstream errmsg;
errmsg << "Error performing Gather! Received error flag: "<<errflag;
utils_error().raise(LOCAL_INFO, errmsg.str());
}
}
template<typename T>
void Gatherv(std::vector<T> &sendbuf, std::vector<T> &recvbuf, std::vector<int> recvcounts, int root)
{
static const MPI_Datatype datatype = get_mpi_data_type<T>::type();
//std::cerr<<"rank "<<Get_rank()<<": Gatherv pars: recvcounts="<<recvcounts<<std::endl;
// We will automatically calculate the displacements assuming that the incoming
// data should just be stacked in the order of the process ranks
std::vector<int> displs;
displs.push_back(0);
std::size_t totalsize = 0;
for(auto it=recvcounts.begin(); it!=recvcounts.end(); ++it)
{
if(std::next(it)!=recvcounts.end()) displs.push_back(*it + displs.back());
totalsize += (*it);
}
if(Get_rank()==0)
{
if(recvbuf.size()<totalsize)
{
std::ostringstream errmsg;
errmsg << "Error performing Gatherv! Recv buffer is not big enough to fit the expected data! We expect messages with total size "<<totalsize<<" but the recv buffer only has size "<<recvbuf.size()<<"!";
utils_error().raise(LOCAL_INFO, errmsg.str());
}
}
//std::cerr<<"rank "<<Get_rank()<<": sendbuf.size()="<<sendbuf.size()<<", recvbuf.size()="<<recvbuf.size()<<", "<<"recvcounts="<<recvcounts<<", displs="<<displs<<std::endl;
int sendcount = sendbuf.size();
int errflag = MPI_Gatherv(&sendbuf[0], sendcount, datatype,
&recvbuf[0], &recvcounts[0], &displs[0],
datatype, root, boundcomm);
if(errflag!=0) {
std::ostringstream errmsg;
errmsg << "Error performing MPI_Gatherv! Received error flag: "<<errflag;
utils_error().raise(LOCAL_INFO, errmsg.str());
}
}
template<typename T>
void AllGather(std::vector<T> &sendbuf, std::vector<T> &recvbuf)
{
static const MPI_Datatype datatype = get_mpi_data_type<T>::type();
int sendcount = sendbuf.size();
int recvcount = sendbuf.size();
if(recvbuf.size()<sendbuf.size()*Get_size())
{
std::ostringstream errmsg;
errmsg << "Error performing AllGather! Recv buffer is not big enough to fit the expected data! We expect "<<Get_size()<<" messages of count "<<recvcount<<", (total size="<<recvcount*Get_size()<<") but the recv buffer only has size "<<recvbuf.size()<<"!";
utils_error().raise(LOCAL_INFO, errmsg.str());
}
int errflag = MPI_Allgather(&sendbuf[0], sendcount, datatype,
&recvbuf[0], recvcount, datatype, boundcomm);
if(errflag!=0) {
std::ostringstream errmsg;
errmsg << "Error performing MPI_Allgather! Received error flag: "<<errflag;
utils_error().raise(LOCAL_INFO, errmsg.str());
}
}
template<typename T>
void AllGatherv(std::vector<T> &sendbuf, std::vector<T> &recvbuf, std::vector<int> recvcounts)
{
static const MPI_Datatype datatype = get_mpi_data_type<T>::type();
// We will automatically calculate the displacements assuming that the incoming
// data should just be stacked in the order of the process ranks
std::vector<int> displs(Get_size());
displs.push_back(0);
for(size_t i=0; i<(recvcounts.size()-1); i++)
{
displs.push_back(i);
}
int sendcount = sendbuf.size();
int errflag = MPI_Allgatherv(&sendbuf[0], sendcount, datatype,
&recvbuf[0], &recvcounts, &displs,
datatype, boundcomm);
if(errflag!=0) {
std::ostringstream errmsg;
errmsg << "Error performing MPI_Allgatherv! Received error flag: "<<errflag;
utils_error().raise(LOCAL_INFO, errmsg.str());
}
}
// Force all processes in this group (possibly all processes in
// the "WORLD"; implementation dependent) to stop executing.
// Useful for abnormal termination (since if one processes throws
// an exception then the others can easily get stuck waiting
// for messages that will never arrive).
void Abort()
{
std::cerr << "rank "<<Get_rank()<<": Issuing MPI_Abort command, attempting to terminate all processes..." << std::endl;
MPI_Abort(boundcomm, 1);
}
/// Tells master to wait until all other processes pass this function, with the specified MPI tag
void masterWaitForAll(int tag);
/// Inverse of the above. Everyone waits for master to pass this (but not for anyone else)
void allWaitForMaster(int tag);
/// Everyone waits for master to pass this, and runs "func" periodically while waiting
void allWaitForMasterWithFunc(int tag, void (*func)());
/// An implementation of Barrier that will fall through if synchronisation takes too long
/// Could modify to take a function pointer to run while waiting.
/// Supply MPI tag to identify each particular barrier.
/// Returns 'false' if barrier succeeds, 'true' if barrier times out (i.e. answers the question "did the barrier time out?")
bool BarrierWithTimeout(const std::chrono::duration<double> timeout, const int tag);
/// This is a fancy barrier that waits a certain amount of time after the FIRST process
/// enters before unlocking (so that other action can be taken). This means that all the
/// processes that enter the barrier *do* get synchronised, even if the barrier unlocks.
/// This helps the synchronisation to be achieved next time.
bool BarrierWithCommonTimeout(std::chrono::duration<double> timeout,
const int tag_entered,
const int tag_timeleft);
/// This routine exists for MPI debugging purposes, to help make sure that
/// all MPI messages are received before MPI_Finalize is called.
/// It doesn't fix any problems, it just lets us notice if they exist.
void check_for_unreceived_messages(int timeout);
/// Receive any waiting messages with a given tag from a given source (possibly MPI_ANY_SOURCE)
/// Need to know what the messages are in order to provide an appropriate Recv buffer (and size)
/// The last message received will remain in the buffer and may be used (useful if several messages
/// about the same thing are expected to pile up)
template<class T>
void Recv_all(T* buffer, int size, int source, int tag, int max_loops)
{
int loop = 0;
MPI_Status status;
while(loop<max_loops and Iprobe(source, tag, &status))
{
#ifdef SIGNAL_DEBUG
LOGGER << "Detected message from process "<<status.MPI_SOURCE<<" with tag "<<status.MPI_TAG<<"; doing Recv" << EOM;
#endif
MPI_Status recv_status;
Recv(buffer, size, status.MPI_SOURCE, status.MPI_TAG, &recv_status);
#ifdef SIGNAL_DEBUG
LOGGER << "Received message from process "<<status.MPI_SOURCE<<" with tag "<<status.MPI_TAG<<". Discarding any existing message in the output buffer as obsolete..." << EOM;
#endif
++loop;
}
if(loop==max_loops)
{
std::ostringstream errmsg;
errmsg << "Error while attempting to clean out unreceived messages from other processes! Received maximum allowed number of messages ("<<loop<<", note that MPI size is "<<Get_size()<<")";
utils_error().raise(LOCAL_INFO, errmsg.str());
}
if(loop>0) LOGGER << "Communicator '"<<myname<<"' received "<<loop<<" messages with tag "<<tag<<". Only the last of these will be readable from the output buffer, the rest were discarded."<<EOM;
}
/// A generic place to store a tag commonly used by this communicator
int mytag = 1;
/// Get pointer to raw bound communicator
MPI_Comm* get_boundcomm() { return &boundcomm; }
/// Get the process ID of the master process (rank 0)
long int MasterPID();
/// Set the process ID of the master process (rank 0)
void set_MasterPID(long int p);
private:
/// The MPI communicator to which the current object "talks".
MPI_Comm boundcomm;
/// A name to identify the communicator group to which this object is bound
std::string myname;
/// The process ID of the master process (rank 0)
static long int pid;
};
/// Check if MPI_Init has been called (it is an error to call it twice)
EXPORT_SYMBOLS bool Is_initialized();
/// Initialise MPI
EXPORT_SYMBOLS void Init();
/// Check if MPI_Finalize has been called (it is an error to do anything else after this)
EXPORT_SYMBOLS bool Is_finalized();
/// Finalize MPI
EXPORT_SYMBOLS void Finalize();
/// Prepare for calling MPI_Finalize, but call MPI_abort and exit function if timeout is exceeded.
EXPORT_SYMBOLS bool PrepareForFinalizeWithTimeout(bool use_mpi_abort);
/// Nice wrapper for getting the message size from an MPI_status struct.
/// Provide the type whose MPI_Datatype you want to retrieve as the
/// template argument.
template<class T>
int Get_count(MPI_Status *status)
{
static const MPI_Datatype datatype = get_mpi_data_type<T>::type();
int msgsize;
MPI_Get_count(status, datatype, &msgsize);
if(msgsize<0)
{
std::ostringstream errmsg;
errmsg << "Error performing MPI_Get_count! Message size returned negative (value was "<<msgsize<<")! This can happen if the number of bytes received is not a multiple of the size of the specified MPI_Datatype. In other words you may have specified a type that doesn't match the type of the sent message; please double-check this.";
utils_error().raise(LOCAL_INFO, errmsg.str());
}
return msgsize;
}
/// @{ Helpers for registration of compound datatypes
/// Structure to hold an MPI startup function plus metadata
class MpiIniFunc
{
private:
std::string location;
std::string name;
void (*func)();
public:
MpiIniFunc(const std::string& l, const std::string& n, void(*f)())
: location(l)
, name(n)
, func(f)
{}
void runme()
{
(*func)();
}
std::string mylocation(){return location;}
std::string myname (){return name;}
};
/// Struct for adding functions to the 'mpi_ini_functions' map
///
/// This will add functions to the map when it is constructed. Works
/// on the same idea as the "ini_code" struct, except it doesn't
/// cause the functions to be run, just "queues them up" so to speak.
// struct AddMpiIniFunc {
// AddMpiIniFunc(const std::string& local_info, const std::string& name, void(*func)());
// };
/// @}
}
}
#endif // include guard
#endif // MPI
Updated on 2024-07-18 at 13:53:32 +0000