MGTransferBlockMatrixFree< dim, Number > Class Template Reference

#include <deal.II/multigrid/mg_transfer_matrix_free.h>

Detailed Description

template<int dim, typename Number>
class MGTransferBlockMatrixFree< dim, Number >

Implementation of the MGTransferBase interface for which the transfer operations is implemented in a matrix-free way based on the interpolation matrices of the underlying finite element. This requires considerably less memory than MGTransferPrebuilt and can also be considerably faster than that variant.

This class works with LinearAlgebra::distributed::BlockVector and performs exactly the same transfer operations for each block as MGTransferMatrixFree. Both the cases that the same DoFHandler is used for all the blocks and that each block uses its own DoFHandler are supported.

Definition at line 1577 of file mg_transfer_matrix_free.h.

Inheritance diagram for MGTransferBlockMatrixFree< dim, Number >:

Public Member Functions
	MGTransferBlockMatrixFree (const MGTransferMatrixFree< dim, Number, ::MemorySpace::Host > &transfer_operator)
	MGTransferBlockMatrixFree ()=default
	MGTransferBlockMatrixFree (const MGConstrainedDoFs &mg_constrained_dofs)
	MGTransferBlockMatrixFree (const std::vector< MGConstrainedDoFs > &mg_constrained_dofs)
void	initialize_constraints (const MGConstrainedDoFs &mg_constrained_dofs)
void	initialize_constraints (const std::vector< MGConstrainedDoFs > &mg_constrained_dofs)
void	build (const DoFHandler< dim > &dof_handler)
void	build (const std::vector< const DoFHandler< dim > * > &dof_handler)
virtual void	prolongate (const unsigned int to_level, LinearAlgebra::distributed::BlockVector< Number > &dst, const LinearAlgebra::distributed::BlockVector< Number > &src) const override
virtual void	prolongate_and_add (const unsigned int to_level, LinearAlgebra::distributed::BlockVector< Number > &dst, const LinearAlgebra::distributed::BlockVector< Number > &src) const override
virtual void	restrict_and_add (const unsigned int from_level, LinearAlgebra::distributed::BlockVector< Number > &dst, const LinearAlgebra::distributed::BlockVector< Number > &src) const override
void	copy_to_mg (const DoFHandler< dim > &dof_handler, MGLevelObject< LinearAlgebra::distributed::BlockVector< Number > > &dst, const BlockVectorType2 &src) const
void	copy_to_mg (const std::vector< const DoFHandler< dim > * > &dof_handler, MGLevelObject< LinearAlgebra::distributed::BlockVector< Number > > &dst, const BlockVectorType2 &src) const
void	copy_from_mg (const DoFHandler< dim > &dof_handler, BlockVectorType2 &dst, const MGLevelObject< LinearAlgebra::distributed::BlockVector< Number > > &src) const
void	copy_from_mg (const std::vector< const DoFHandler< dim > * > &dof_handler, BlockVectorType2 &dst, const MGLevelObject< LinearAlgebra::distributed::BlockVector< Number > > &src) const
template<class Archive >
void	serialize (Archive &ar, const unsigned int version)
Querying the observer pointers an object has.
unsigned int	n_subscriptions () const
template<typename StreamType >
void	list_subscribers (StreamType &stream) const
void	list_subscribers () const

Static Public Member Functions
static ::ExceptionBase &	ExcInUse (int arg1, std::string arg2, std::string arg3)
static ::ExceptionBase &	ExcNoSubscriber (std::string arg1, std::string arg2)

Protected Member Functions
const MGTransferMatrixFree< dim, Number, ::MemorySpace::Host > &	get_matrix_free_transfer (const unsigned int b) const override

Protected Attributes
const bool	same_for_all

Private Member Functions
EnableObserverPointer functionality
Classes derived from EnableObserverPointer provide a facility to subscribe to this object. This is mostly used by the ObserverPointer class.
void	subscribe (std::atomic< bool > *const validity, const std::string &identifier="") const
void	unsubscribe (std::atomic< bool > *const validity, const std::string &identifier="") const
void	check_no_subscribers () const noexcept

Private Attributes
std::vector< MGTransferMatrixFree< dim, Number, ::MemorySpace::Host > >	transfer_operators_internal
std::vector< ObserverPointer< const MGTransferMatrixFree< dim, Number, ::MemorySpace::Host > > >	transfer_operators
std::atomic< unsigned int >	counter
std::map< std::string, unsigned int >	counter_map
std::vector< std::atomic< bool > * >	validity_pointers
const std::type_info *	object_info

Static Private Attributes
static std::mutex	mutex

Constructor & Destructor Documentation

MGTransferBlockMatrixFree() [1/4]

template<int dim, typename Number >

MGTransferBlockMatrixFree< dim, Number >::MGTransferBlockMatrixFree

(

const MGTransferMatrixFree< dim, Number, ::MemorySpace::Host > &

transfer_operator

)

Constructor.

MGTransferBlockMatrixFree() [2/4]

template<int dim, typename Number >

MGTransferBlockMatrixFree< dim, Number >::MGTransferBlockMatrixFree ( )

default

Constructor without constraint matrices. Use this constructor only with discontinuous finite elements or with no local refinement.

MGTransferBlockMatrixFree() [3/4]

template<int dim, typename Number >

MGTransferBlockMatrixFree< dim, Number >::MGTransferBlockMatrixFree

(

const MGConstrainedDoFs &

mg_constrained_dofs

)

Constructor with constraints. Equivalent to the default constructor followed by initialize_constraints().

MGTransferBlockMatrixFree() [4/4]

template<int dim, typename Number >

MGTransferBlockMatrixFree< dim, Number >::MGTransferBlockMatrixFree

(

const std::vector< MGConstrainedDoFs > &

mg_constrained_dofs

)

Same as above for the case that each block has its own DoFHandler.

Member Function Documentation

initialize_constraints() [1/2]

template<int dim, typename Number >

void MGTransferBlockMatrixFree< dim, Number >::initialize_constraints

(

const MGConstrainedDoFs &

mg_constrained_dofs

)

Initialize the constraints to be used in build().

initialize_constraints() [2/2]

template<int dim, typename Number >

void MGTransferBlockMatrixFree< dim, Number >::initialize_constraints

(

const std::vector< MGConstrainedDoFs > &

mg_constrained_dofs

)

Same as above for the case that each block has its own DoFHandler.

build() [1/2]

template<int dim, typename Number >

void MGTransferBlockMatrixFree< dim, Number >::build

(

const DoFHandler< dim > &

dof_handler

)

Actually build the information for the prolongation for each level.

build() [2/2]

template<int dim, typename Number >

void MGTransferBlockMatrixFree< dim, Number >::build

(

const std::vector< const DoFHandler< dim > * > &

dof_handler

)

Same as above for the case that each block has its own DoFHandler.

get_matrix_free_transfer()

template<int dim, typename Number >

const MGTransferMatrixFree< dim, Number, ::MemorySpace::Host > & MGTransferBlockMatrixFree< dim, Number >::get_matrix_free_transfer ( const unsigned int  b ) const

overrideprotectedvirtual

Return the right non-block transfer operator. Has to be implemented by the derived class.

Implements MGTransferBlockMatrixFreeBase< dim, Number, MGTransferMatrixFree< dim, Number, ::MemorySpace::Host > >.

prolongate()

virtual void MGTransferBlockMatrixFreeBase< dim, Number, MGTransferMatrixFree< dim, Number, ::MemorySpace::Host > >::prolongate ( const unsigned int  to_level, LinearAlgebra::distributed::BlockVector< Number > &  dst, const LinearAlgebra::distributed::BlockVector< Number > &  src  ) const

overridevirtualinherited

Prolongate a vector from level to_level-1 to level to_level using the embedding matrices of the underlying finite element. The previous content of dst is overwritten.

Parameters

to_level	The index of the level to prolongate to, which is the level of dst.
src	is a vector with as many elements as there are degrees of freedom on the coarser level involved.
dst	has as many elements as there are degrees of freedom on the finer level.

Implements MGTransferBase< LinearAlgebra::distributed::BlockVector< Number > >.

prolongate_and_add()

virtual void MGTransferBlockMatrixFreeBase< dim, Number, MGTransferMatrixFree< dim, Number, ::MemorySpace::Host > >::prolongate_and_add ( const unsigned int  to_level, LinearAlgebra::distributed::BlockVector< Number > &  dst, const LinearAlgebra::distributed::BlockVector< Number > &  src  ) const

overridevirtualinherited

Prolongate a vector from level to_level-1 to level to_level, summing into the previous content of dst.

Parameters

[in]	to_level	The destination level of the operation.
[in]	src	A vector with as many elements as there are degrees of freedom on the coarser level involved.
[out]	dst	The output vector. It must have as many elements as there are degrees of freedom on the finer level.

Reimplemented from MGTransferBase< LinearAlgebra::distributed::BlockVector< Number > >.

restrict_and_add()

virtual void MGTransferBlockMatrixFreeBase< dim, Number, MGTransferMatrixFree< dim, Number, ::MemorySpace::Host > >::restrict_and_add ( const unsigned int  from_level, LinearAlgebra::distributed::BlockVector< Number > &  dst, const LinearAlgebra::distributed::BlockVector< Number > &  src  ) const

overridevirtualinherited

Restrict a vector from level from_level to level from_level-1 using the transpose operation of the prolongate() method. If the region covered by cells on level from_level is smaller than that of level from_level-1 (local refinement), then some degrees of freedom in dst are active and will not be altered. For the other degrees of freedom, the result of the restriction is added.

Parameters

from_level	The index of the level to restrict from, which is the level of src.
src	is a vector with as many elements as there are degrees of freedom on the finer level involved.
dst	has as many elements as there are degrees of freedom on the coarser level.

Implements MGTransferBase< LinearAlgebra::distributed::BlockVector< Number > >.

copy_to_mg() [1/2]

void MGTransferBlockMatrixFreeBase< dim, Number, MGTransferMatrixFree< dim, Number, ::MemorySpace::Host > >::copy_to_mg ( const DoFHandler< dim > &  dof_handler, MGLevelObject< LinearAlgebra::distributed::BlockVector< Number > > &  dst, const BlockVectorType2 &  src  ) const

inherited

Transfer from a block-vector on the global grid to block-vectors defined on each of the levels separately for active degrees of freedom. In particular, for a globally refined mesh only the finest level in dst is filled as a plain copy of src. All the other level objects are left untouched.

This function will initialize dst accordingly if needed as required by the Multigrid class.

copy_to_mg() [2/2]

void MGTransferBlockMatrixFreeBase< dim, Number, MGTransferMatrixFree< dim, Number, ::MemorySpace::Host > >::copy_to_mg ( const std::vector< const DoFHandler< dim > * > &  dof_handler, MGLevelObject< LinearAlgebra::distributed::BlockVector< Number > > &  dst, const BlockVectorType2 &  src  ) const

inherited

Same as above for the case that each block has its own DoFHandler.

copy_from_mg() [1/2]

void MGTransferBlockMatrixFreeBase< dim, Number, MGTransferMatrixFree< dim, Number, ::MemorySpace::Host > >::copy_from_mg ( const DoFHandler< dim > &  dof_handler, BlockVectorType2 &  dst, const MGLevelObject< LinearAlgebra::distributed::BlockVector< Number > > &  src  ) const

inherited

Transfer from multi-level block-vector to normal vector.

copy_from_mg() [2/2]

void MGTransferBlockMatrixFreeBase< dim, Number, MGTransferMatrixFree< dim, Number, ::MemorySpace::Host > >::copy_from_mg ( const std::vector< const DoFHandler< dim > * > &  dof_handler, BlockVectorType2 &  dst, const MGLevelObject< LinearAlgebra::distributed::BlockVector< Number > > &  src  ) const

inherited

Same as above for the case that each block has its own DoFHandler.

n_subscriptions()

unsigned int EnableObserverPointer::n_subscriptions ( ) const

inlineinherited

Return the present number of subscriptions to this object. This allows to use this class for reference counted lifetime determination where the last one to unsubscribe also deletes the object.

Definition at line 318 of file enable_observer_pointer.h.

list_subscribers() [1/2]

template<typename StreamType >

void EnableObserverPointer::list_subscribers ( StreamType &  stream ) const

inlineinherited

List the subscribers to the input stream.

Definition at line 335 of file enable_observer_pointer.h.

list_subscribers() [2/2]

void EnableObserverPointer::list_subscribers ( ) const

inherited

List the subscribers to deallog.

Definition at line 200 of file enable_observer_pointer.cc.

serialize()

template<class Archive >

void EnableObserverPointer::serialize ( Archive &  ar, const unsigned int  version  )

inlineinherited

Read or write the data of this object to or from a stream for the purpose of serialization using the BOOST serialization library.

This function does not actually serialize any of the member variables of this class. The reason is that what this class stores is only who subscribes to this object, but who does so at the time of storing the contents of this object does not necessarily have anything to do with who subscribes to the object when it is restored. Consequently, we do not want to overwrite the subscribers at the time of restoring, and then there is no reason to write the subscribers out in the first place.

Definition at line 327 of file enable_observer_pointer.h.

subscribe()

void EnableObserverPointer::subscribe ( std::atomic< bool > *const  validity, const std::string &  identifier = ""  ) const

privateinherited

Subscribes a user of the object by storing the pointer validity. The subscriber may be identified by text supplied as identifier.

Definition at line 136 of file enable_observer_pointer.cc.

unsubscribe()

void EnableObserverPointer::unsubscribe ( std::atomic< bool > *const  validity, const std::string &  identifier = ""  ) const

privateinherited

Unsubscribes a user from the object.

Note

The identifier and the validity pointer must be the same as the one supplied to subscribe().

Definition at line 154 of file enable_observer_pointer.cc.

check_no_subscribers()

void EnableObserverPointer::check_no_subscribers ( ) const

privatenoexceptinherited

Check that there are no objects subscribing to this object. If this check passes then it is safe to destroy the current object. It this check fails then this function will either abort or print an error message to deallog (by using the AssertNothrow mechanism), but will not throw an exception.

Note

Since this function is just a consistency check it does nothing in release mode.

If this function is called when there is an uncaught exception then, rather than aborting, this function prints an error message to the standard error stream and returns.

Definition at line 58 of file enable_observer_pointer.cc.

Member Data Documentation

transfer_operators_internal

template<int dim, typename Number >

std::vector<MGTransferMatrixFree<dim, Number, ::MemorySpace::Host> > MGTransferBlockMatrixFree< dim, Number >::transfer_operators_internal

private

Internal non-block version of transfer operation.

Definition at line 1643 of file mg_transfer_matrix_free.h.

transfer_operators

template<int dim, typename Number >

std::vector<ObserverPointer< const MGTransferMatrixFree<dim, Number, ::MemorySpace::Host> > > MGTransferBlockMatrixFree< dim, Number >::transfer_operators

private

Non-block version of transfer operation.

Definition at line 1650 of file mg_transfer_matrix_free.h.

same_for_all

const bool MGTransferBlockMatrixFreeBase< dim, Number, MGTransferMatrixFree< dim, Number, ::MemorySpace::Host > >::same_for_all

protectedinherited

A flag to indicate whether the same DoFHandler is used for all the components or if each block has its own DoFHandler.

Definition at line 1560 of file mg_transfer_matrix_free.h.

counter

std::atomic<unsigned int> EnableObserverPointer::counter

mutableprivateinherited

Store the number of objects which subscribed to this object. Initially, this number is zero, and upon destruction it shall be zero again (i.e. all objects which subscribed should have unsubscribed again).

The creator (and owner) of an object is counted in the map below if HE manages to supply identification.

We use the mutable keyword in order to allow subscription to constant objects also.

This counter may be read from and written to concurrently in multithreaded code: hence we use the std::atomic class template.

Definition at line 212 of file enable_observer_pointer.h.

counter_map

std::map<std::string, unsigned int> EnableObserverPointer::counter_map

mutableprivateinherited

In this map, we count subscriptions for each different identification string supplied to subscribe().

Definition at line 218 of file enable_observer_pointer.h.

validity_pointers

std::vector<std::atomic<bool> *> EnableObserverPointer::validity_pointers

mutableprivateinherited

In this vector, we store pointers to the validity bool in the ObserverPointer objects that subscribe to this class.

Definition at line 224 of file enable_observer_pointer.h.

object_info

const std::type_info* EnableObserverPointer::object_info

mutableprivateinherited

Pointer to the typeinfo object of this object, from which we can later deduce the class name. Since this information on the derived class is neither available in the destructor, nor in the constructor, we obtain it in between and store it here.

Definition at line 232 of file enable_observer_pointer.h.

mutex

std::mutex EnableObserverPointer::mutex

staticprivateinherited

A mutex used to ensure data consistency when accessing the mutable members of this class. This lock is used in the subscribe() and unsubscribe() functions, as well as in list_subscribers().

Definition at line 239 of file enable_observer_pointer.h.

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

• include/deal.II/multigrid/mg_transfer_matrix_free.h