Reference documentation for deal.II version 9.6.0
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BlockInfo Class Reference

A small class collecting the different BlockIndices involved in global, multilevel and local computations. More...

#include <deal.II/dofs/block_info.h>

Inheritance diagram for BlockInfo:

Public Member Functions

template<int dim, int spacedim>
void initialize (const DoFHandler< dim, spacedim > &, bool levels_only=false, bool active_only=false)
 Fill the object with values describing block structure of the DoFHandler.
 
template<int dim, int spacedim>
void initialize_local (const DoFHandler< dim, spacedim > &)
 Initialize block structure on cells and compute renumbering between cell dofs and block cell dofs.
 
const BlockIndicesglobal () const
 
const BlockIndiceslocal () const
 
const BlockIndiceslevel (unsigned int level) const
 
types::global_dof_index renumber (const unsigned int i) const
 
unsigned int n_base_elements () const
 
unsigned int base_element (const unsigned int i) const
 
template<class OS >
void print (OS &stream) const
 
std::size_t memory_consumption () const
 
template<class Archive >
void serialize (Archive &ar, const unsigned int)
 
Subscriptor functionality

Classes derived from Subscriptor provide a facility to subscribe to this object. This is mostly used by the SmartPointer 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 ::ExceptionBaseExcInUse (int arg1, std::string arg2, std::string arg3)
 
static ::ExceptionBaseExcNoSubscriber (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

BlockIndices bi_global
 The block structure of the global system.
 
std::vector< BlockIndiceslevels
 The multilevel block structure.
 
BlockIndices bi_local
 The block structure of the cell systems.
 
std::vector< unsigned intbase_elements
 
std::vector< types::global_dof_indexlocal_renumbering
 
std::atomic< unsigned intcounter
 
std::map< std::string, unsigned intcounter_map
 
std::vector< std::atomic< bool > * > validity_pointers
 
const std::type_info * object_info
 

Static Private Attributes

static std::mutex mutex
 

Detailed Description

A small class collecting the different BlockIndices involved in global, multilevel and local computations.

Once a DoFHandler has been initialized with an FESystem, a data object of type BlockInfo (accessed by DoFHandler::block_info() ) is filled, which reflects the block structure of the degrees of freedom.

BlockInfo consists of several BlockIndices objects. The member global() reflects the block structure of the system on the active cell level, usually referred to as the global system. As soon as DoFHandler::distribute_dofs() has been called, the function BlockIndices::block_size() in global() will return the correct sizes of each block. After DoFRenumbering::block_wise(), BlockIndices::block_start() will return the start index for each of the blocks.

When a DoFHandler with levels is used, the same structure is automatically generated for each level. The level blocks can be accessed through level().

Finally, there are local() BlockIndices, which describe the block structure on a single cell. This is used for instance by MeshWorker::Assembler::MatrixLocalBlocksToGlobalBlocks. The local indices are not filled automatically, since they change the behavior of the MeshWorker::Assembler classes relying on BlockInfo. They must be initialized by hand through initialize_local().

Usage

The most common usage for this object is initializing vectors as in the following code:

dof_handler.distribute_dofs(fe_system);
dof_handler.distribute_mg_dofs(fe_system);
BlockVector<double> solution(dof_handler.block_info().global());
for (unsigned int i = 0; i < triangulation.n_levels(); ++i)
{
mg_vector[i].reinit(dof_handler.block_info().level(i));
}
unsigned int n_levels() const
void block_wise(DoFHandler< dim, spacedim > &dof_handler)
const ::parallel::distributed::Triangulation< dim, spacedim > * triangulation

In this example, solution obtains the block structure needed to represent a finite element function on the DoFHandler. Similarly, all levels of mg_vector will have the block structure needed on that level.

Todo
Extend the functions local() and renumber() to allow for hp-capablilites.

Definition at line 94 of file block_info.h.

Member Typedef Documentation

◆ map_value_type

using Subscriptor::map_value_type = decltype(counter_map)::value_type
privateinherited

The data type used in counter_map.

Definition at line 229 of file subscriptor.h.

◆ map_iterator

using Subscriptor::map_iterator = decltype(counter_map)::iterator
privateinherited

The iterator type used in counter_map.

Definition at line 234 of file subscriptor.h.

Member Function Documentation

◆ initialize()

template<int dim, int spacedim>
void BlockInfo::initialize ( const DoFHandler< dim, spacedim > & dof,
bool levels_only = false,
bool active_only = false )

Fill the object with values describing block structure of the DoFHandler.

By default, this function will attempt to initialize whatever is possible. If active dofs have been assigned int the DoFHandler argument, they BlockIndices for those will be generated. The same for level dofs.

This default behavior can be overridden by the two parameters, which can switch off active dofs or level dofs.

This function will also clear the local() indices.

Definition at line 29 of file block_info.cc.

◆ initialize_local()

template<int dim, int spacedim>
void BlockInfo::initialize_local ( const DoFHandler< dim, spacedim > & dof)

Initialize block structure on cells and compute renumbering between cell dofs and block cell dofs.

Definition at line 61 of file block_info.cc.

◆ global()

const BlockIndices & BlockInfo::global ( ) const
inline

Access the BlockIndices structure of the global system.

Definition at line 221 of file block_info.h.

◆ local()

const BlockIndices & BlockInfo::local ( ) const
inline

Access BlockIndices for the local system on a cell.

Definition at line 228 of file block_info.h.

◆ level()

const BlockIndices & BlockInfo::level ( unsigned int level) const
inline

Access the BlockIndices structure of a level in the multilevel hierarchy.

Definition at line 235 of file block_info.h.

◆ renumber()

types::global_dof_index BlockInfo::renumber ( const unsigned int i) const
inline

Return the index after local renumbering.

The input of this function is an index between zero and the number of dofs per cell, numbered in local block ordering, that is first all indices of the first system block, then all of the second block and so forth. The function then outputs the index in the standard local numbering of DoFAccessor.

Definition at line 243 of file block_info.h.

◆ n_base_elements()

unsigned int BlockInfo::n_base_elements ( ) const
inline

The number of base elements.

Definition at line 260 of file block_info.h.

◆ base_element()

unsigned int BlockInfo::base_element ( const unsigned int i) const
inline

Return the base element of this index.

Definition at line 251 of file block_info.h.

◆ print()

template<class OS >
void BlockInfo::print ( OS & stream) const
inline

Write a summary of the block structure to the stream.

Definition at line 269 of file block_info.h.

◆ memory_consumption()

std::size_t BlockInfo::memory_consumption ( ) const
inline

Determine an estimate for the memory consumption (in bytes) of this object.

Definition at line 301 of file block_info.h.

◆ serialize()

template<class Archive >
void BlockInfo::serialize ( Archive & ar,
const unsigned int  )

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

Definition at line 312 of file block_info.h.

◆ subscribe()

void Subscriptor::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 135 of file subscriptor.cc.

◆ unsubscribe()

void Subscriptor::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 155 of file subscriptor.cc.

◆ n_subscriptions()

unsigned int Subscriptor::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 300 of file subscriptor.h.

◆ list_subscribers() [1/2]

template<typename StreamType >
void Subscriptor::list_subscribers ( StreamType & stream) const
inlineinherited

List the subscribers to the input stream.

Definition at line 317 of file subscriptor.h.

◆ list_subscribers() [2/2]

void Subscriptor::list_subscribers ( ) const
inherited

List the subscribers to deallog.

Definition at line 203 of file subscriptor.cc.

◆ check_no_subscribers()

void Subscriptor::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 52 of file subscriptor.cc.

Member Data Documentation

◆ bi_global

BlockIndices BlockInfo::bi_global
private

The block structure of the global system.

Definition at line 193 of file block_info.h.

◆ levels

std::vector<BlockIndices> BlockInfo::levels
private

The multilevel block structure.

Definition at line 197 of file block_info.h.

◆ bi_local

BlockIndices BlockInfo::bi_local
private

The block structure of the cell systems.

Definition at line 202 of file block_info.h.

◆ base_elements

std::vector<unsigned int> BlockInfo::base_elements
private

The base element associated with each block.

Definition at line 207 of file block_info.h.

◆ local_renumbering

std::vector<types::global_dof_index> BlockInfo::local_renumbering
private

A vector containing the renumbering from the standard order of degrees of freedom on a cell to a component wise ordering. Filled by initialize().

Definition at line 213 of file block_info.h.

◆ counter

std::atomic<unsigned int> Subscriptor::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 218 of file subscriptor.h.

◆ counter_map

std::map<std::string, unsigned int> Subscriptor::counter_map
mutableprivateinherited

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

Definition at line 224 of file subscriptor.h.

◆ validity_pointers

std::vector<std::atomic<bool> *> Subscriptor::validity_pointers
mutableprivateinherited

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

Definition at line 240 of file subscriptor.h.

◆ object_info

const std::type_info* Subscriptor::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 248 of file subscriptor.h.

◆ mutex

std::mutex Subscriptor::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 271 of file subscriptor.h.


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