kamping::Environment< init_finalize_mode > Class Template Reference

Wrapper for MPI functions that don't require a communicator. If the template parameter init_finalize_mode is set to InitMPIMode::InitFinalize (default), MPI_Init is called in the constructor, and MPI_Finalize is called in the destructor. More...

#include <environment.hpp>

Public Member Functions
	Environment (int &argc, char **&argv)
	Calls MPI_Init with arguments.
	Environment ()
	Calls MPI_Init without arguments.
void	init_unchecked () const
	Calls MPI_Init without arguments and doesn't check whether MPI_Init has already been called.
void	init_unchecked (int &argc, char **&argv) const
	Calls MPI_Init with arguments and doesn't check whether MPI_Init has already been called.
void	init () const
	Calls MPI_Init without arguments. Checks whether MPI_Init has already been called first.
void	init (int &argc, char **&argv) const
	Calls MPI_Init with arguments. Checks whether MPI_Init has already been called first.
void	finalize () const
	Calls MPI_Finalize and frees all registered MPI data types.
bool	initialized () const
	Checks whether MPI_Init has been called.
bool	finalized () const
	Checks whether MPI_Finalize has been called.
template<typename T >
void	buffer_attach (Span< T > buffer)
	Attach a buffer to use for buffered send operations to the environment.
template<typename T = std::byte>
Span< T >	buffer_detach ()
	Detach a buffer attached via buffer_attach().
	~Environment ()
	Calls MPI_Finalize if finalize() has not been called before. Also frees all registered MPI data types.

Static Public Member Functions
static double	wtime ()
	Returns the elapsed time since an arbitrary time in the past.
static double	wtick ()
	Returns the resolution of Environment::wtime().
static int	tag_upper_bound ()
	The upper bound on message tags defined by the MPI implementation.
static bool	is_valid_tag (int tag)
	Checks if the given tag is a valid message tag.
static void	register_mpi_type (MPI_Datatype type)
	Register a new MPI data type to KaMPIng that will be freed when using Environment to finalize MPI.
static void	commit (MPI_Datatype type)
	Commit an MPI data type (without registering it with KaMPIng).
static void	free (MPI_Datatype type)
	Free an MPI data type.
static void	commit_and_register (MPI_Datatype type)
	Commit an MPI data type and register it with KaMPIng.
static void	free_registered_mpi_types ()
	Free all registered MPI data types.

Static Public Attributes
static size_t const	bsend_overhead = MPI_BSEND_OVERHEAD

Detailed Description

template<InitMPIMode init_finalize_mode = InitMPIMode::InitFinalize>
class kamping::Environment< init_finalize_mode >

Wrapper for MPI functions that don't require a communicator. If the template parameter init_finalize_mode is set to InitMPIMode::InitFinalize (default), MPI_Init is called in the constructor, and MPI_Finalize is called in the destructor.

Note that MPI_Init and MPI_Finalize are global, meaning that if they are called on an Environment object they must not be called again in any Environment object (or directly vie the MPI_* calls).

Constructor & Destructor Documentation

Environment()

template<InitMPIMode init_finalize_mode = InitMPIMode::InitFinalize>

kamping::Environment< init_finalize_mode >::Environment ( int & argc, char **& argv )

inline

Calls MPI_Init with arguments.

Parameters

argc	Number of arguments.
argv	The arguments.

Member Function Documentation

buffer_attach()

template<InitMPIMode init_finalize_mode = InitMPIMode::InitFinalize>

template<typename T >

void kamping::Environment< init_finalize_mode >::buffer_attach ( Span< T > buffer )

inline

Attach a buffer to use for buffered send operations to the environment.

Template Parameters

T	The type of the buffer.

Parameters

buffer

The buffer. The user is responsible for allocating the buffer, attaching it, detaching it and freeing the memory after detaching. For convenience, the buffer may be a span of any type, but the type is ignored by MPI.

buffer_detach()

template<InitMPIMode init_finalize_mode = InitMPIMode::InitFinalize>

template<typename T = std::byte>

Span< T > kamping::Environment< init_finalize_mode >::buffer_detach ( )

inline

Detach a buffer attached via buffer_attach().

Template Parameters

T	The type of the span to return. Defaults to std::byte.

Returns

A span pointing to the previously attached buffer. The type of the returned span can be controlled via the parameter T. The pointer to the buffer stored internally by MPI is reinterpreted accordingly.

commit_and_register()

template<InitMPIMode init_finalize_mode = InitMPIMode::InitFinalize>

static void kamping::Environment< init_finalize_mode >::commit_and_register ( MPI_Datatype type )

inlinestatic

Commit an MPI data type and register it with KaMPIng.

See also

commit()

register_type()

finalize()

template<InitMPIMode init_finalize_mode = InitMPIMode::InitFinalize>

void kamping::Environment< init_finalize_mode >::finalize ( ) const

inline

Calls MPI_Finalize and frees all registered MPI data types.

Even if you chose InitMPIMode::InitFinalize, you might want to call this function: As MPI_Finalize could potentially return an error, this function can be used if you want to be able to handle that error. Otherwise the destructor will call MPI_Finalize and not throw on any errors returned.

finalized()

template<InitMPIMode init_finalize_mode = InitMPIMode::InitFinalize>

bool kamping::Environment< init_finalize_mode >::finalized ( ) const

inline

Checks whether MPI_Finalize has been called.

Returns

true if MPI_Finalize has been called, false otherwise.

free_registered_mpi_types()

template<InitMPIMode init_finalize_mode = InitMPIMode::InitFinalize>

static void kamping::Environment< init_finalize_mode >::free_registered_mpi_types ( )

inlinestatic

Free all registered MPI data types.

Only call this when you no longer want to use any MPI data types created by KaMPIng as other KaMPIng functions will assume the created types still exist.

init()

template<InitMPIMode init_finalize_mode = InitMPIMode::InitFinalize>

void kamping::Environment< init_finalize_mode >::init ( int & argc, char **& argv ) const

inline

Calls MPI_Init with arguments. Checks whether MPI_Init has already been called first.

Parameters

argc	Number of arguments.
argv	The arguments.

init_unchecked()

template<InitMPIMode init_finalize_mode = InitMPIMode::InitFinalize>

void kamping::Environment< init_finalize_mode >::init_unchecked ( int & argc, char **& argv ) const

inline

Calls MPI_Init with arguments and doesn't check whether MPI_Init has already been called.

Parameters

argc	Number of arguments.
argv	The arguments.

initialized()

template<InitMPIMode init_finalize_mode = InitMPIMode::InitFinalize>

bool kamping::Environment< init_finalize_mode >::initialized ( ) const

inline

Checks whether MPI_Init has been called.

Returns

true if MPI_Init has been called, false otherwise.

is_valid_tag()

template<InitMPIMode init_finalize_mode = InitMPIMode::InitFinalize>

static bool kamping::Environment< init_finalize_mode >::is_valid_tag ( int tag )

inlinestatic

Checks if the given tag is a valid message tag.

Returns

Whether the tag is valid.

register_mpi_type()

template<InitMPIMode init_finalize_mode = InitMPIMode::InitFinalize>

static void kamping::Environment< init_finalize_mode >::register_mpi_type ( MPI_Datatype type )

inlinestatic

Register a new MPI data type to KaMPIng that will be freed when using Environment to finalize MPI.

Parameters

type	The MPI data type to register.

tag_upper_bound()

template<InitMPIMode init_finalize_mode = InitMPIMode::InitFinalize>

static int kamping::Environment< init_finalize_mode >::tag_upper_bound ( )

inlinestatic

The upper bound on message tags defined by the MPI implementation.

Returns

The upper bound for tags.

wtick()

template<InitMPIMode init_finalize_mode = InitMPIMode::InitFinalize>

static double kamping::Environment< init_finalize_mode >::wtick ( )

inlinestatic

Returns the resolution of Environment::wtime().

Returns

The resolution in seconds.

wtime()

template<InitMPIMode init_finalize_mode = InitMPIMode::InitFinalize>

static double kamping::Environment< init_finalize_mode >::wtime ( )

inlinestatic

Returns the elapsed time since an arbitrary time in the past.

Returns

The elapsed time in seconds.

Member Data Documentation

bsend_overhead

template<InitMPIMode init_finalize_mode = InitMPIMode::InitFinalize>

size_t const kamping::Environment< init_finalize_mode >::bsend_overhead = MPI_BSEND_OVERHEAD

inlinestatic

Provides an upper bound on the additional memory required by buffered send operations.

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The documentation for this class was generated from the following file:

• include/kamping/environment.hpp