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

Inheritance diagram for MGSmoother< VectorType >:

[legend]

Public Member Functions
	MGSmoother (const unsigned int steps=1, const bool variable=false, const bool symmetric=false, const bool transpose=false)

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	clear ()=0

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< VectorType >	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
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 VectorType>
class MGSmoother< VectorType >

A base class for smoother handling information on smoothing. While not adding to the abstract interface in MGSmootherBase, this class stores information on the number and type of smoothing steps, which in turn can be used by a derived class.

Definition at line 49 of file mg_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

◆ MGSmoother()

template<typename VectorType >

MGSmoother< VectorType >::MGSmoother	(	const unsigned int	steps = `1`,
		const bool	variable = `false`,
		const bool	symmetric = `false`,
		const bool	transpose = `false`
	)

Constructor.

Member Function Documentation

◆ set_steps()

template<typename VectorType >

void MGSmoother< VectorType >::set_steps ( const unsigned int )

Modify the number of smoothing steps on finest level.

◆ set_variable()

template<typename VectorType >

void MGSmoother< VectorType >::set_variable ( const bool )

Switch on/off variable smoothing.

◆ set_symmetric()

template<typename VectorType >

void MGSmoother< VectorType >::set_symmetric ( const bool )

Switch on/off symmetric smoothing.

◆ set_transpose()

template<typename VectorType >

void MGSmoother< VectorType >::set_transpose ( const bool )

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

◆ set_debug()

template<typename VectorType >

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

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

◆ clear()

template<typename VectorType >

virtual void MGSmootherBase< VectorType >::clear ( )

pure virtualinherited

Release matrices.

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

◆ smooth()

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);

MGSmootherBase::smooth

virtual void smooth(const unsigned int level, VectorType &u, const VectorType &rhs) const =0

level

unsigned int level

Definition grid_out.cc:4632

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

◆ vector_memory

template<typename VectorType >

GrowingVectorMemory<VectorType> MGSmoother< VectorType >::vector_memory

mutableprotected

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

template<typename VectorType >

unsigned int MGSmoother< VectorType >::steps

protected

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

template<typename VectorType >

bool MGSmoother< VectorType >::variable

protected

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

template<typename VectorType >

bool MGSmoother< VectorType >::symmetric

protected

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

Definition at line 117 of file mg_smoother.h.

◆ transpose

template<typename VectorType >

bool MGSmoother< VectorType >::transpose

protected

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

template<typename VectorType >

unsigned int MGSmoother< VectorType >::debug

protected

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.

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

include/deal.II/multigrid/mg_smoother.h

Public Member Functions

Static Public Member Functions

Protected Attributes

Private Types

Private Member Functions

Private Attributes

Static Private Attributes

Detailed Description

Member Typedef Documentation

◆ map_value_type

◆ map_iterator

Constructor & Destructor Documentation

◆ MGSmoother()

Member Function Documentation

◆ set_steps()

◆ set_variable()

◆ set_symmetric()

◆ set_transpose()

◆ set_debug()

◆ clear()

◆ smooth()

◆ apply()

◆ subscribe()

◆ unsubscribe()

◆ n_subscriptions()

◆ list_subscribers() [1/2]

◆ list_subscribers() [2/2]

◆ serialize()

◆ check_no_subscribers()

Member Data Documentation

◆ vector_memory

◆ steps

◆ variable

◆ symmetric

◆ transpose

◆ debug

◆ counter

◆ counter_map

◆ validity_pointers

◆ object_info

◆ mutex