MGSmootherBlock< MatrixType, RelaxationType, number > Class Template Reference

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

Inheritance diagram for MGSmootherBlock< MatrixType, RelaxationType, number >:

Public Member Functions
	MGSmootherBlock (const unsigned int steps=1, const bool variable=false, const bool symmetric=false, const bool transpose=false, const bool reverse=false)
template<typename MGMatrixType , typename MGRelaxationType >
void	initialize (const MGMatrixType &matrices, const MGRelaxationType &smoothers)
void	clear ()
void	set_reverse (const bool)
virtual void	smooth (const unsigned int level, BlockVector< number > &u, const BlockVector< number > &rhs) const
std::size_t	memory_consumption () const
void	set_steps (const unsigned int)
void	set_variable (const bool)
void	set_symmetric (const bool)
void	set_transpose (const bool)
void	set_debug (const unsigned int level)
virtual void	smooth (const unsigned int level, VectorType &u, const VectorType &rhs) const =0
virtual void	apply (const unsigned int level, VectorType &u, const VectorType &rhs) const
template<class Archive >
void	serialize (Archive &ar, const unsigned int version)
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
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 Attributes
GrowingVectorMemory< BlockVector< number > >	vector_memory
unsigned int	steps
bool	variable
bool	symmetric
bool	transpose
unsigned int	debug

Private Types
using	map_value_type = decltype(counter_map)::value_type
using	map_iterator = decltype(counter_map)::iterator

Private Member Functions
void	check_no_subscribers () const noexcept

Private Attributes
MGLevelObject< LinearOperator< BlockVector< number > > >	matrices
MGLevelObject< LinearOperator< BlockVector< number > > >	smoothers
bool	reverse
ObserverPointer< VectorMemory< BlockVector< number > >, MGSmootherBlock< MatrixType, RelaxationType, number > >	mem
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

Detailed Description

template<typename MatrixType, typename RelaxationType, typename number>
class MGSmootherBlock< MatrixType, RelaxationType, number >

General smoother class for block vectors. This class gives complete freedom to the choice of a block smoother by being initialized with a matrix and a smoother object. Therefore, the smoother object for each level must be constructed by hand.

Definition at line 50 of file mg_block_smoother.h.

Member Typedef Documentation

map_value_type

using EnableObserverPointer::map_value_type = decltype(counter_map)::value_type

privateinherited

The data type used in counter_map.

Definition at line 238 of file enable_observer_pointer.h.

map_iterator

using EnableObserverPointer::map_iterator = decltype(counter_map)::iterator

privateinherited

The iterator type used in counter_map.

Definition at line 243 of file enable_observer_pointer.h.

Constructor & Destructor Documentation

MGSmootherBlock()

template<typename MatrixType , typename RelaxationType , typename number >

MGSmootherBlock< MatrixType, RelaxationType, number >::MGSmootherBlock	(	const unsigned int	steps = 1,
		const bool	variable = false,
		const bool	symmetric = false,
		const bool	transpose = false,
		const bool	reverse = false
	)

Constructor.

Member Function Documentation

initialize()

template<typename MatrixType , typename RelaxationType , typename number >

template<typename MGMatrixType , typename MGRelaxationType >

void MGSmootherBlock< MatrixType, RelaxationType, number >::initialize	(	const MGMatrixType &	matrices,
		const MGRelaxationType &	smoothers
	)

Initialize for matrices. The parameter matrices can be any object having functions get_minlevel() and get_maxlevel() as well as an operator[] returning a reference to MatrixType.

The same convention is used for the parameter smoothers, such that operator[] returns the object doing the block-smoothing on a single level.

This function stores pointers to the level matrices and smoothing operator for each level.

clear()

template<typename MatrixType , typename RelaxationType , typename number >

void MGSmootherBlock< MatrixType, RelaxationType, number >::clear ( )

virtual

Empty all vectors.

Implements MGSmootherBase< VectorType >.

set_reverse()

template<typename MatrixType , typename RelaxationType , typename number >

void MGSmootherBlock< MatrixType, RelaxationType, number >::set_reverse

(

const bool

)

Switch on/off reversed. This is mutually exclusive with transpose().

smooth() [1/2]

template<typename MatrixType , typename RelaxationType , typename number >

virtual void MGSmootherBlock< MatrixType, RelaxationType, number >::smooth ( const unsigned int  level, BlockVector< number > &  u, const BlockVector< number > &  rhs  ) const

virtual

Implementation of the interface for Multigrid. This function does nothing, which by comparison with the definition of this function means that the smoothing operator equals the null operator.

memory_consumption()

template<typename MatrixType , typename RelaxationType , typename number >

std::size_t MGSmootherBlock< MatrixType, RelaxationType, number >::memory_consumption

(

)

const

Memory used by this object.

set_steps()

void MGSmoother< BlockVector< number > >::set_steps ( const unsigned int  )

inherited

Modify the number of smoothing steps on finest level.

set_variable()

void MGSmoother< BlockVector< number > >::set_variable ( const bool  )

inherited

Switch on/off variable smoothing.

set_symmetric()

void MGSmoother< BlockVector< number > >::set_symmetric ( const bool  )

inherited

Switch on/off symmetric smoothing.

set_transpose()

void MGSmoother< BlockVector< number > >::set_transpose ( const bool  )

inherited

Switch on/off transposed smoothing. The effect is overridden by set_symmetric().

set_debug()

void MGSmoother< BlockVector< number > >::set_debug ( const unsigned int  level )

inherited

Set debug to a nonzero value to get debug information logged to deallog. Increase to get more information

smooth() [2/2]

template<typename VectorType >

virtual void MGSmootherBase< VectorType >::smooth ( const unsigned int  level, VectorType &  u, const VectorType &  rhs  ) const

pure virtualinherited

Smoothing function that smooths the content in u given the right hand side vector rhs. This is the function used in multigrid methods.

Implemented in MGSmootherIdentity< VectorType >, MGSmootherRelaxation< MatrixType, RelaxationType, VectorType >, mg::SmootherRelaxation< RelaxationType, VectorType >, and MGSmootherPrecondition< MatrixType, PreconditionerType, VectorType >.

apply()

template<typename VectorType >

void MGSmootherBase< VectorType >::apply ( const unsigned int  level, VectorType &  u, const VectorType &  rhs  ) const

virtualinherited

As opposed to the smooth() function, this function applies the action of the smoothing, overwriting the previous content in the vector u. This function must be equivalent to the following code

u = 0;
smooth(level, u, rhs);

but can usually be implemented more efficiently than the former. If a particular smoother does not override the apply() method, the default implementation as described here is used.

In the multigrid preconditioner interfaces, the apply() method is used for the pre-smoothing operation because the previous content in the solution vector needs to be overwritten for a new incoming residual. On the other hand, all subsequent operations need to smooth the content already present in the vector u given the right hand side, which is done by smooth().

Reimplemented in MGSmootherRelaxation< MatrixType, RelaxationType, VectorType >, mg::SmootherRelaxation< RelaxationType, VectorType >, and MGSmootherPrecondition< MatrixType, PreconditionerType, VectorType >.

Definition at line 33 of file mg_base.cc.

subscribe()

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

inherited

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

Definition at line 131 of file enable_observer_pointer.cc.

unsubscribe()

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

inherited

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 151 of file enable_observer_pointer.cc.

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 322 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 339 of file enable_observer_pointer.h.

list_subscribers() [2/2]

void EnableObserverPointer::list_subscribers ( ) const

inherited

List the subscribers to deallog.

Definition at line 199 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 331 of file enable_observer_pointer.h.

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 53 of file enable_observer_pointer.cc.

Member Data Documentation

matrices

template<typename MatrixType , typename RelaxationType , typename number >

MGLevelObject<LinearOperator<BlockVector<number> > > MGSmootherBlock< MatrixType, RelaxationType, number >::matrices

private

Pointer to the matrices.

Definition at line 111 of file mg_block_smoother.h.

smoothers

template<typename MatrixType , typename RelaxationType , typename number >

MGLevelObject<LinearOperator<BlockVector<number> > > MGSmootherBlock< MatrixType, RelaxationType, number >::smoothers

private

Pointer to the matrices.

Definition at line 116 of file mg_block_smoother.h.

reverse

template<typename MatrixType , typename RelaxationType , typename number >

bool MGSmootherBlock< MatrixType, RelaxationType, number >::reverse

private

Reverse?

Definition at line 121 of file mg_block_smoother.h.

mem

template<typename MatrixType , typename RelaxationType , typename number >

ObserverPointer<VectorMemory<BlockVector<number> >, MGSmootherBlock<MatrixType, RelaxationType, number> > MGSmootherBlock< MatrixType, RelaxationType, number >::mem

private

Memory for auxiliary vectors.

Definition at line 128 of file mg_block_smoother.h.

vector_memory

GrowingVectorMemory<BlockVector< number > > MGSmoother< BlockVector< number > >::vector_memory

mutableprotectedinherited

A memory object to be used for temporary vectors.

The object is marked as mutable since we will need to use it to allocate temporary vectors also in functions that are const.

Definition at line 99 of file mg_smoother.h.

steps

unsigned int MGSmoother< BlockVector< number > >::steps

protectedinherited

Number of smoothing steps on the finest level. If no variable smoothing is chosen, this is the number of steps on all levels.

Definition at line 105 of file mg_smoother.h.

variable

bool MGSmoother< BlockVector< number > >::variable

protectedinherited

Variable smoothing: double the number of smoothing steps whenever going to the next coarser level

Definition at line 111 of file mg_smoother.h.

symmetric

bool MGSmoother< BlockVector< number > >::symmetric

protectedinherited

Symmetric smoothing: in the smoothing iteration, alternate between the relaxation method and its transpose.

Definition at line 117 of file mg_smoother.h.

transpose

bool MGSmoother< BlockVector< number > >::transpose

protectedinherited

Use the transpose of the relaxation method instead of the method itself. This has no effect if symmetric smoothing is chosen.

Definition at line 123 of file mg_smoother.h.

debug

unsigned int MGSmoother< BlockVector< number > >::debug

protectedinherited

Output debugging information to deallog if this is nonzero.

Definition at line 128 of file mg_smoother.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 227 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 233 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 249 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 257 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 280 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_block_smoother.h