PreconditionUseMatrix< MatrixType, VectorType > Class Template Reference

#include <deal.II/lac/precondition.h>

Inheritance diagram for PreconditionUseMatrix< MatrixType, VectorType >:

Public Types
using	function_ptr = void(MatrixType::*)(VectorType &, const VectorType &) const

Public Member Functions
	PreconditionUseMatrix (const MatrixType &M, const function_ptr method)
void	vmult (VectorType &dst, const VectorType &src) 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)

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
const MatrixType &	matrix
const function_ptr	precondition
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 = SparseMatrix<double>, typename VectorType = Vector<double>>
class PreconditionUseMatrix< MatrixType, VectorType >

Preconditioner using a matrix-builtin function. This class forms a preconditioner suitable for the LAC solver classes. Since many preconditioning methods are based on matrix entries, these have to be implemented as member functions of the underlying matrix implementation. This class now is intended to allow easy access to these member functions from LAC solver classes.

It seems that all builtin preconditioners have a relaxation parameter, so please use PreconditionRelaxation for these.

You will usually not want to create a named object of this type, although possible. The most common use is like this:

SolverGMRES<SparseMatrix<double> Vector<double>> gmres(control,memory,500);
 
gmres.solve(
  matrix, solution, right_hand_side,
  PreconditionUseMatrix<SparseMatrix<double>,Vector<double> >(
    matrix, &SparseMatrix<double>::template precondition_Jacobi<double>));

This creates an unnamed object to be passed as the fourth parameter to the solver function of the SolverGMRES class. It assumes that the SparseMatrix class has a function precondition_Jacobi taking two vectors (source and destination) as parameters (Actually, there is no function like that, the existing function takes a third parameter, denoting the relaxation parameter; this example is therefore only meant to illustrate the general idea).

Note that due to the default template parameters, the above example could be written shorter as follows:

...
gmres.solve(
  matrix, solution, right_hand_side,
  PreconditionUseMatrix<>(
    matrix,&SparseMatrix<double>::template precondition_Jacobi<double>));

Definition at line 497 of file precondition.h.

Member Typedef Documentation

function_ptr

template<typename MatrixType = SparseMatrix<double>, typename VectorType = Vector<double>>

using PreconditionUseMatrix< MatrixType, VectorType >::function_ptr = void (MatrixType::*)(VectorType &, const VectorType &) const

Type of the preconditioning function of the matrix.

Definition at line 503 of file precondition.h.

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

PreconditionUseMatrix()

template<typename MatrixType = SparseMatrix<double>, typename VectorType = Vector<double>>

PreconditionUseMatrix< MatrixType, VectorType >::PreconditionUseMatrix	(	const MatrixType &	M,
		const function_ptr	method
	)

Constructor. This constructor stores a reference to the matrix object for later use and selects a preconditioning method, which must be a member function of that matrix.

Member Function Documentation

vmult()

template<typename MatrixType = SparseMatrix<double>, typename VectorType = Vector<double>>

void PreconditionUseMatrix< MatrixType, VectorType >::vmult	(	VectorType &	dst,
		const VectorType &	src
	)		const

Execute preconditioning. Calls the function passed to the constructor of this object with the two arguments given here.

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

matrix

template<typename MatrixType = SparseMatrix<double>, typename VectorType = Vector<double>>

const MatrixType& PreconditionUseMatrix< MatrixType, VectorType >::matrix

private

Pointer to the matrix in use.

Definition at line 524 of file precondition.h.

precondition

template<typename MatrixType = SparseMatrix<double>, typename VectorType = Vector<double>>

const function_ptr PreconditionUseMatrix< MatrixType, VectorType >::precondition

private

Pointer to the preconditioning function.

Definition at line 529 of file precondition.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/lac/precondition.h