deal.II version GIT relicensing-2250-g88cb8ba3cb 2024-12-13 12:20:00+00:00
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#include <deal.II/lac/precondition.h>
Classes | |
struct | AdditionalData |
Public Types | |
using | size_type = types::global_dof_index |
Public Member Functions | |
PreconditionIdentity () | |
template<typename MatrixType > | |
void | initialize (const MatrixType &matrix, const AdditionalData &additional_data=AdditionalData()) |
template<typename VectorType > | |
void | vmult (VectorType &, const VectorType &) const |
template<typename VectorType > | |
void | Tvmult (VectorType &, const VectorType &) const |
template<typename VectorType > | |
void | vmult_add (VectorType &, const VectorType &) const |
template<typename VectorType > | |
void | Tvmult_add (VectorType &, const VectorType &) const |
void | clear () |
size_type | m () const |
size_type | n () 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 | |
size_type | n_rows |
size_type | n_columns |
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 |
This preconditioner implements the identity operator. This class can be used you if you want to use a linear solver without preconditioning, because all linear solvers require the usage of a preconditioner.
It can be used in the following way:
See the step-3 tutorial program for an example and additional explanations.
Alternatively, the IdentityMatrix class can be used to precondition in this way.
Definition at line 218 of file precondition.h.
Declare type for container size.
Definition at line 224 of file precondition.h.
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privateinherited |
The data type used in counter_map.
Definition at line 238 of file enable_observer_pointer.h.
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privateinherited |
The iterator type used in counter_map.
Definition at line 243 of file enable_observer_pointer.h.
PreconditionIdentity::PreconditionIdentity | ( | ) |
Constructor, sets the domain and range sizes to their defaults.
void PreconditionIdentity::initialize | ( | const MatrixType & | matrix, |
const AdditionalData & | additional_data = AdditionalData() |
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) |
The matrix argument is ignored and here just for compatibility with more complex preconditioners.
void PreconditionIdentity::vmult | ( | VectorType & | , |
const VectorType & | |||
) | const |
Apply preconditioner.
void PreconditionIdentity::Tvmult | ( | VectorType & | , |
const VectorType & | |||
) | const |
Apply transpose preconditioner. Since this is the identity, this function is the same as vmult().
void PreconditionIdentity::vmult_add | ( | VectorType & | , |
const VectorType & | |||
) | const |
Apply preconditioner, adding to the previous value.
void PreconditionIdentity::Tvmult_add | ( | VectorType & | , |
const VectorType & | |||
) | const |
Apply transpose preconditioner, adding. Since this is the identity, this function is the same as vmult_add().
void PreconditionIdentity::clear | ( | ) |
This function is only present to provide the interface of a preconditioner to be handed to a smoother. This does nothing.
size_type PreconditionIdentity::m | ( | ) | const |
Return the dimension of the codomain (or range) space. Note that the matrix is of dimension \(m \times n\).
size_type PreconditionIdentity::n | ( | ) | const |
Return the dimension of the domain space. Note that the matrix is of dimension \(m \times n\).
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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.
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inherited |
Unsubscribes a user from the object.
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.
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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.
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inlineinherited |
List the subscribers to the input stream
.
Definition at line 339 of file enable_observer_pointer.h.
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inherited |
List the subscribers to deallog
.
Definition at line 199 of file enable_observer_pointer.cc.
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.
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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.
Definition at line 53 of file enable_observer_pointer.cc.
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private |
The dimension of the range space.
Definition at line 313 of file precondition.h.
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private |
The dimension of the domain space.
Definition at line 318 of file precondition.h.
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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.
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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.
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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.
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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.
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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.