multisim.cpp File Reference

#include "gmxpre.h"
#include "multisim.h"
#include "config.h"
#include <cinttypes>
#include <filesystem>
#include <limits>
#include "gromacs/gmxlib/network.h"
#include "gromacs/mdtypes/commrec.h"
#include "gromacs/utility/arrayref.h"
#include "gromacs/utility/exceptions.h"
#include "gromacs/utility/fatalerror.h"
#include "gromacs/utility/futil.h"
#include "gromacs/utility/gmxassert.h"
#include "gromacs/utility/logger.h"
#include "gromacs/utility/mpitypes.h"
#include "gromacs/utility/smalloc.h"

Include dependency graph for multisim.cpp:

Description

Implements the multi-simulation support routines.

Author

Mark Abraham mark..nosp@m.j.ab.nosp@m.raham.nosp@m.@gma.nosp@m.il.co.nosp@m.m

Berk Hess hess@.nosp@m.kth..nosp@m.se

Functions
std::unique_ptr< gmx_multisim_t >	buildMultiSimulation (MPI_Comm worldComm, gmx::ArrayRef< const std::string > multidirs)
	Builder function for gmx_multisim_t. More...
template<typename T >
static void	mpiAllSumReduce (const int nr, T r[], MPI_Comm mpi_comm)
	Sums array r of size nr over mpi_comm, the result is available on all ranks.
template<typename T >
static void	mpiAllSumReduce (gmx::ArrayRef< T > r, MPI_Comm mpi_comm)
	Sums array r over mpi_comm, the result is available on all ranks, size of r should not exceed MAX_INT.
void	gmx_sumd_sim (int nr, double r[], const gmx_multisim_t *ms)
	Calculate the sum over the simulations of an array of doubles.
void	gmx_sumf_sim (int nr, float r[], const gmx_multisim_t *ms)
	Calculate the sum over the simulations of an array of floats.
void	gmx_sumi_sim (int nr, int r[], const gmx_multisim_t *ms)
	Calculate the sum over the simulations of an array of ints.
void	gmx_sumli_sim (gmx::ArrayRef< int64_t > r, const gmx_multisim_t &ms)
	Calculate the sum over the simulations of an array of large ints, the size of r cannot exceed MAX_INT.
std::vector< int >	gatherIntFromMultiSimulation (const gmx_multisim_t *ms, const int localValue)
	Return a vector containing the gathered values of localValue found on the main rank of each simulation.
template<typename T >
static bool	multiSimValuesAllAreEqual (const gmx_multisim_t &ms, const T value, std::vector< T > *externalBuffer=nullptr)
	Returns whether value is equal on all main ranks in ms. More...
template<typename T >
static void	checkMultiInt (FILE *log, const gmx_multisim_t &ms, const T val, const char *name)
	Checks whether values val are equal on all main ranks of ms. More...
void	check_multi_int (FILE *log, const gmx_multisim_t &ms, int val, const char *name, bool beQuiet)
	Check if val is the same on all simulations for a mdrun -multidir run. More...
void	check_multi_int64 (FILE *log, const gmx_multisim_t &ms, int64_t val, const char *name, bool beQuiet)
	Check if val is the same on all simulations for a mdrun -multidir run. More...
bool	findIsSimulationMainRank (const gmx_multisim_t *ms, MPI_Comm communicator)
	Return whether this rank is the main rank of a simulation, using ms (if it is valid) and otherwise communicator.
bool	isMainSim (const gmx_multisim_t *ms)
	Are we the main simulation of a possible multi-simulation?
bool	isMainSimMainRank (const gmx_multisim_t *ms, const bool isMain)
	Are we the main rank (of the main simulation, for a multi-sim). More...
void	logInitialMultisimStatus (const gmx_multisim_t &ms, const t_commrec *cr, const gmx::MDLogger &mdlog, const bool simulationsShareState, const int numSteps, const int initialStep)
	Log the initial state of the multi-sim. More...

Function Documentation

std::unique_ptr<gmx_multisim_t> buildMultiSimulation	(	MPI_Comm	worldComm,
		gmx::ArrayRef< const std::string >	multidirs
	)

Builder function for gmx_multisim_t.

Parameters

[in]	worldComm	MPI communicator to split when multi-simulation is requested.
[in]	multidirs	Strings naming the subdirectories when multi-simulation is requested, otherwise empty

Splits worldComm into multidirs.size() separate simulations, if >1, and creates a communication structure between the main ranks of these simulations.

Valid to call regardless of build configuration, but multidirs must be empty unless a real MPI build is used.

Exceptions

NotImplementedError	when multidirs is non-empty unless using real MPI is true
NotImplementedError	when multidirs has exactly one element
InconsistentInputError	when the number of MPI ranks is not a multiple of the number of multidirs
FileIOError	when the simulation cannot change to the working directory in multidirs

void check_multi_int	(	FILE *	log,
		const gmx_multisim_t &	ms,
		int	val,
		const char *	name,
		bool	beQuiet
	)

Check if val is the same on all simulations for a mdrun -multidir run.

The string name is used to print to the log file and in a fatal error if the val's don't match. If beQuiet is true and the check passes, no output is written.

void check_multi_int64	(	FILE *	log,
		const gmx_multisim_t &	ms,
		int64_t	val,
		const char *	name,
		bool	beQuiet
	)

Check if val is the same on all simulations for a mdrun -multidir run.

The string name is used to print to the log file and in a fatal error if the val's don't match. If beQuiet is true and the check passes, no output is written.

template<typename T >

static void checkMultiInt ( FILE *  log, const gmx_multisim_t &  ms, const T  val, const char *  name  )

static

Checks whether values val are equal on all main ranks of ms.

Parameters

[in]	log	Pointer to the loga file, can be nullptr
[in]	ms	Multi-simulation communication setup
[in]	val	The value to check
[in]	name	The name to print to log, can be nullptr when log==nullptr

bool isMainSimMainRank	(	const gmx_multisim_t *	ms,
		bool	isMain
	)

Are we the main rank (of the main simulation, for a multi-sim).

This rank prints the remaining run time etc.

void logInitialMultisimStatus	(	const gmx_multisim_t &	ms,
		const t_commrec *	cr,
		const gmx::MDLogger &	mdlog,
		bool	simulationsShareState,
		int	numSteps,
		int	initialStep
	)

Log the initial state of the multi-sim.

The simulations may be at different steps, etc so we report that.

Parameters

[in]	ms	The multi-sum object
[in]	cr	The commrec object
[in]	mdlog	Logger
[in]	simulationsShareState	Whether the simulations share state
[in]	numSteps	The number of steps in this simulation
[in]	initialStep	The initial step for this simulation

template<typename T >

static bool multiSimValuesAllAreEqual ( const gmx_multisim_t &  ms, const T  value, std::vector< T > *  externalBuffer = nullptr  )

static

Returns whether value is equal on all main ranks in ms.

Optionally an external buffer can be passed in externaBuffer. This will then hold values of value of each main rank in ms.