BlockIndices Class Reference

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

Inheritance diagram for BlockIndices:

Public Types
using	size_type = types::global_dof_index

Public Member Functions
	BlockIndices ()
	BlockIndices (const std::vector< size_type > &block_sizes)
	BlockIndices (BlockIndices &&b) noexcept
	BlockIndices (const BlockIndices &)=default
	BlockIndices (const unsigned int n_blocks, const size_type block_size=0)
void	reinit (const unsigned int n_blocks, const size_type n_elements_per_block)
void	reinit (const std::vector< size_type > &block_sizes)
void	push_back (const size_type size)
BlockIndices &	operator= (const BlockIndices &b)
BlockIndices &	operator= (BlockIndices &&) noexcept
bool	operator== (const BlockIndices &b) const
void	swap (BlockIndices &b) noexcept
std::size_t	memory_consumption () const
template<class Archive >
void	serialize (Archive &ar, const unsigned int version)
Size information
unsigned int	size () const
size_type	total_size () const
size_type	block_size (const unsigned int i) const
std::string	to_string () const
Index conversion
Functions in this group assume an object, which was created after sorting by block, such that each block forms a set of consecutive indices in the object. If applied to other objects, the numbers obtained from these functions are meaningless.
std::pair< unsigned int, size_type >	global_to_local (const size_type i) const
size_type	local_to_global (const unsigned int block, const size_type index) const
size_type	block_start (const unsigned int i) const
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 ::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
unsigned int	n_blocks
std::vector< size_type >	start_indices
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

Related Symbols
(Note that these are not member symbols.)
void	swap (BlockIndices &u, BlockIndices &v) noexcept

Detailed Description

BlockIndices represents a range of indices (such as the range \([0,N)\) of valid indices for elements of a vector) and how this one range is broken down into smaller but contiguous "blocks" (such as the velocity and pressure parts of a solution vector). In particular, it provides the ability to translate between global indices and the indices within a block. This class is used, for example, in the BlockVector, BlockSparsityPattern, and BlockMatrixBase classes.

The information that can be obtained from this class falls into two groups. First, it is possible to query the global size of the index space (through the total_size() member function), and the number of blocks and their sizes (via size() and the block_size() functions).

Secondly, this class manages the conversion of global indices to the local indices within this block, and the other way around. This is required, for example, when you address a global element in a block vector and want to know within which block this is, and which index within this block it corresponds to. It is also useful if a matrix is composed of several blocks, where you have to translate global row and column indices to local ones.

See also

Block (linear algebra)

Definition at line 59 of file block_indices.h.

Member Typedef Documentation

size_type

using BlockIndices::size_type = types::global_dof_index

Declare the type for container size.

Definition at line 65 of file block_indices.h.

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.

Constructor & Destructor Documentation

BlockIndices() [1/5]

BlockIndices::BlockIndices ( )

inline

Default constructor. Initialize for zero blocks.

Definition at line 281 of file block_indices.h.

BlockIndices() [2/5]

BlockIndices::BlockIndices ( const std::vector< size_type > & block_sizes )

inline

Constructor. Initialize the number of entries in each block i as block_sizes[i]. The number of blocks will be the size of block_sizes.

Definition at line 299 of file block_indices.h.

BlockIndices() [3/5]

BlockIndices::BlockIndices ( BlockIndices && b )

inlinenoexcept

Move constructor. Initialize a new object by stealing the internal data of another BlockIndices object.

Definition at line 308 of file block_indices.h.

BlockIndices() [4/5]

BlockIndices::BlockIndices ( const BlockIndices & )

default

Copy constructor.

BlockIndices() [5/5]

BlockIndices::BlockIndices ( const unsigned int n_blocks, const size_type block_size = 0 )

inlineexplicit

Specialized constructor for a structure with blocks of equal size.

Definition at line 288 of file block_indices.h.

Member Function Documentation

reinit() [1/2]

void BlockIndices::reinit ( const unsigned int n_blocks, const size_type n_elements_per_block )

inline

Reinitialize the number of blocks and assign each block the same number of elements.

Definition at line 257 of file block_indices.h.

reinit() [2/2]

void BlockIndices::reinit ( const std::vector< size_type > & block_sizes )

inline

Reinitialize the number of indices within each block from the given argument. The number of blocks will be adjusted to the size of block_sizes and the size of block i is set to block_sizes[i].

Definition at line 268 of file block_indices.h.

push_back()

void BlockIndices::push_back ( const size_type size )

inline

Add another block of given size to the end of the block structure.

Definition at line 319 of file block_indices.h.

size()

unsigned int BlockIndices::size ( ) const

inline

Number of blocks in index field.

Definition at line 353 of file block_indices.h.

total_size()

BlockIndices::size_type BlockIndices::total_size ( ) const

inline

Return the total number of indices accumulated over all blocks, that is, the dimension of the vector space of the block vector.

Definition at line 361 of file block_indices.h.

block_size()

BlockIndices::size_type BlockIndices::block_size ( const unsigned int i ) const

inline

The size of the ith block.

Definition at line 371 of file block_indices.h.

to_string()

std::string BlockIndices::to_string ( ) const

inline

String representation of the block sizes. The output is of the form [nb->b1,b2,b3|s], where nb is n_blocks(), s is total_size() and b1 etc. are the values returned by block_size() for each of the blocks.

Definition at line 380 of file block_indices.h.

global_to_local()

std::pair< unsigned int, BlockIndices::size_type > BlockIndices::global_to_local ( const size_type i ) const

inline

Return the block and the index within that block for the global index i. The first element of the pair is the block, the second the index within it.

Definition at line 328 of file block_indices.h.

local_to_global()

BlockIndices::size_type BlockIndices::local_to_global ( const unsigned int block, const size_type index ) const

inline

Return the global index of index in block block.

Definition at line 342 of file block_indices.h.

block_start()

BlockIndices::size_type BlockIndices::block_start ( const unsigned int i ) const

inline

The start index of the ith block.

Definition at line 396 of file block_indices.h.

operator=() [1/2]

BlockIndices & BlockIndices::operator= ( const BlockIndices & b )

inline

Copy operator.

Definition at line 405 of file block_indices.h.

operator=() [2/2]

BlockIndices & BlockIndices::operator= ( BlockIndices && b )

inlinenoexcept

Move assignment operator. Move another BlockIndices object onto the current one by transferring its contents.

Definition at line 415 of file block_indices.h.

operator==()

bool BlockIndices::operator== ( const BlockIndices & b ) const

inline

Compare whether two objects are the same, i.e. whether the number of blocks and the sizes of all blocks are equal.

Definition at line 429 of file block_indices.h.

swap()

void BlockIndices::swap ( BlockIndices & b )

inlinenoexcept

Swap the contents of these two objects.

Definition at line 444 of file block_indices.h.

memory_consumption()

std::size_t BlockIndices::memory_consumption ( ) const

inline

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

Definition at line 453 of file block_indices.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.

serialize()

template<class Archive >

void Subscriptor::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 309 of file subscriptor.h.

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.

Friends And Related Symbol Documentation

swap()

void swap ( BlockIndices & u, BlockIndices & v )

related

Global function swap which overloads the default implementation of the C++ standard library which uses a temporary object. The function simply exchanges the data of the two objects.

Definition at line 471 of file block_indices.h.

Member Data Documentation

n_blocks

unsigned int BlockIndices::n_blocks

private

Number of blocks. While this value could be obtained through start_indices.size()-1, we cache this value for faster access.

Definition at line 221 of file block_indices.h.

start_indices

std::vector<size_type> BlockIndices::start_indices

private

Global starting index of each vector. The last and redundant value is the total number of entries.

Definition at line 227 of file block_indices.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.

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

• include/deal.II/lac/block_indices.h