GridTools::Cache< dim, spacedim > Class Template Reference

#include <deal.II/grid/grid_tools_cache.h>

Inheritance diagram for GridTools::Cache< dim, spacedim >:

Public Member Functions
	Cache (const Triangulation< dim, spacedim > &tria, const Mapping< dim, spacedim > &mapping)
	Cache (const Triangulation< dim, spacedim > &tria)
	~Cache () override
void	mark_for_update (const CacheUpdateFlags &flags=update_all)
const std::vector< std::set< typename Triangulation< dim, spacedim >::active_cell_iterator > > &	get_vertex_to_cell_map () const
const std::vector< std::vector< Tensor< 1, spacedim > > > &	get_vertex_to_cell_centers_directions () const
const std::map< unsigned int, Point< spacedim > > &	get_used_vertices () const
const RTree< std::pair< Point< spacedim >, unsigned int > > &	get_used_vertices_rtree () const
const RTree< std::pair< BoundingBox< spacedim >, typename Triangulation< dim, spacedim >::active_cell_iterator > > &	get_cell_bounding_boxes_rtree () const
const RTree< std::pair< BoundingBox< spacedim >, typename Triangulation< dim, spacedim >::active_cell_iterator > > &	get_locally_owned_cell_bounding_boxes_rtree () const
const std::vector< std::set< unsigned int > > &	get_vertex_to_neighbor_subdomain () const
const std::map< unsigned int, std::set< types::subdomain_id > > &	get_vertices_with_ghost_neighbors () const
const Triangulation< dim, spacedim > &	get_triangulation () const
const Mapping< dim, spacedim > &	get_mapping () const
const RTree< std::pair< BoundingBox< spacedim >, unsigned int > > &	get_covering_rtree (const unsigned int level=0) 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
std::atomic< std::underlying_type_t< CacheUpdateFlags > >	update_flags
ObserverPointer< const Triangulation< dim, spacedim >, Cache< dim, spacedim > >	tria
ObserverPointer< const Mapping< dim, spacedim >, Cache< dim, spacedim > >	mapping
std::vector< std::set< typename Triangulation< dim, spacedim >::active_cell_iterator > >	vertex_to_cells
std::mutex	vertex_to_cells_mutex
std::vector< std::vector< Tensor< 1, spacedim > > >	vertex_to_cell_centers
std::mutex	vertex_to_cell_centers_mutex
std::map< unsigned int, RTree< std::pair< BoundingBox< spacedim >, unsigned int > > >	covering_rtree
std::mutex	covering_rtree_mutex
std::map< unsigned int, Point< spacedim > >	used_vertices
std::mutex	used_vertices_mutex
RTree< std::pair< Point< spacedim >, unsigned int > >	used_vertices_rtree
std::mutex	used_vertices_rtree_mutex
RTree< std::pair< BoundingBox< spacedim >, typename Triangulation< dim, spacedim >::active_cell_iterator > >	cell_bounding_boxes_rtree
std::mutex	cell_bounding_boxes_rtree_mutex
RTree< std::pair< BoundingBox< spacedim >, typename Triangulation< dim, spacedim >::active_cell_iterator > >	locally_owned_cell_bounding_boxes_rtree
std::mutex	locally_owned_cell_bounding_boxes_rtree_mutex
std::vector< std::set< unsigned int > >	vertex_to_neighbor_subdomain
std::mutex	vertex_to_neighbor_subdomain_mutex
std::map< unsigned int, std::set<::types::subdomain_id > >	vertices_with_ghost_neighbors
std::mutex	vertices_with_ghost_neighbors_mutex
boost::signals2::connection	tria_change_signal
boost::signals2::connection	tria_create_signal
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<int dim, int spacedim = dim>
class GridTools::Cache< dim, spacedim >

A class that caches computationally intensive information about a Triangulation.

This class attaches a signal to the Triangulation passed at construction time to keep track about refinement changes, and allows the user to query some of the data structures constructed using functions in the GridTools namespace which are computed only once, and then cached inside this class for faster access whenever the triangulation has not changed.

Notice that this class only notices if the underlying Triangulation has changed due to a Triangulation::Signals::any_change() signal being triggered.

If the triangulation changes for other reasons, for example because you use it in conjunction with a MappingQEulerian object that sees the vertices through its own transformation, or because you manually change some vertex locations, then some of the structures in this class become obsolete, and you will have to mark them as outdated, by calling the method mark_for_update() manually.

Definition at line 66 of file grid_tools_cache.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

Cache() [1/2]

template<int dim, int spacedim>

GridTools::Cache< dim, spacedim >::Cache	(	const Triangulation< dim, spacedim > &	tria,
		const Mapping< dim, spacedim > &	mapping
	)

Constructor.

If you provide the optional mapping argument, then this is used whenever a mapping is required.

Parameters

tria	The triangulation for which to store information.
mapping	The Mapping to use when computing cached objects.

Definition at line 27 of file grid_tools_cache.cc.

Cache() [2/2]

template<int dim, int spacedim>

GridTools::Cache< dim, spacedim >::Cache

(

const Triangulation< dim, spacedim > &

tria

)

Constructor. Uses the default linear or multilinear mapping for the underlying ReferenceCell of tria.

Parameters

tria	The triangulation for which to store information.

Definition at line 40 of file grid_tools_cache.cc.

~Cache()

template<int dim, int spacedim>

GridTools::Cache< dim, spacedim >::~Cache ( )

override

Destructor.

Definition at line 68 of file grid_tools_cache.cc.

Member Function Documentation

mark_for_update()

template<int dim, int spacedim>

void GridTools::Cache< dim, spacedim >::mark_for_update

(

const CacheUpdateFlags &

flags = update_all

)

Make sure that the objects marked for update are recomputed during subsequent calls to the get_* functions defined in this class.

Notice that no work is performed when you call this function. The actual data structures are computed the next time you call the corresponding get_* method.

Parameters

flags

What to mark for update

Definition at line 80 of file grid_tools_cache.cc.

get_vertex_to_cell_map()

template<int dim, int spacedim>

const std::vector< std::set< typename Triangulation< dim, spacedim >::active_cell_iterator > > & GridTools::Cache< dim, spacedim >::get_vertex_to_cell_map

(

)

const

Return the cached vertex_to_cell_map as computed by GridTools::vertex_to_cell_map().

Definition at line 90 of file grid_tools_cache.cc.

get_vertex_to_cell_centers_directions()

template<int dim, int spacedim>

const std::vector< std::vector< Tensor< 1, spacedim > > > & GridTools::Cache< dim, spacedim >::get_vertex_to_cell_centers_directions

(

)

const

Return the cached vertex_to_cell_centers_directions as computed by GridTools::vertex_to_cell_centers_directions().

Definition at line 114 of file grid_tools_cache.cc.

get_used_vertices()

template<int dim, int spacedim>

const std::map< unsigned int, Point< spacedim > > & GridTools::Cache< dim, spacedim >::get_used_vertices

(

)

const

Return the cached map of used vertices, as computed by GridTools::extract_used_vertices().

Definition at line 139 of file grid_tools_cache.cc.

get_used_vertices_rtree()

template<int dim, int spacedim>

const RTree< std::pair< Point< spacedim >, unsigned int > > & GridTools::Cache< dim, spacedim >::get_used_vertices_rtree

(

)

const

Return the cached RTree object for the vertices, constructed using the used vertices of the triangulation.

Definition at line 163 of file grid_tools_cache.cc.

get_cell_bounding_boxes_rtree()

template<int dim, int spacedim>

const RTree< std::pair< BoundingBox< spacedim >, typename Triangulation< dim, spacedim >::active_cell_iterator > > & GridTools::Cache< dim, spacedim >::get_cell_bounding_boxes_rtree

(

)

const

Return the cached RTree object of the cell bounding boxes, constructed using the active cell iterators of the stored triangulation. For parallel::distributed::Triangulation objects, this function will return also the bounding boxes of ghost and artificial cells.

Definition at line 195 of file grid_tools_cache.cc.

get_locally_owned_cell_bounding_boxes_rtree()

template<int dim, int spacedim>

const RTree< std::pair< BoundingBox< spacedim >, typename Triangulation< dim, spacedim >::active_cell_iterator > > & GridTools::Cache< dim, spacedim >::get_locally_owned_cell_bounding_boxes_rtree

(

)

const

Return the cached RTree object of bounding boxes containing locally owned active cells, constructed using the active cell iterators of the stored triangulation.

In contrast to the previous function, this function builds the RTree using only the locally owned cells, i.e., not including ghost or artificial cells. The two functions return the same result in serial computations.

Definition at line 229 of file grid_tools_cache.cc.

get_vertex_to_neighbor_subdomain()

template<int dim, int spacedim>

const std::vector< std::set< unsigned int > > & GridTools::Cache< dim, spacedim >::get_vertex_to_neighbor_subdomain

(

)

const

Returns the vector of set of integer containing the subdomain id to which each vertex is connected to. This feature is used extensively in the particle_handler to detect on which processors ghost particles must be built.

Definition at line 309 of file grid_tools_cache.cc.

get_vertices_with_ghost_neighbors()

template<int dim, int spacedim>

const std::map< unsigned int, std::set< types::subdomain_id > > & GridTools::Cache< dim, spacedim >::get_vertices_with_ghost_neighbors

(

)

const

Return a map that, for each vertex, lists all the processes whose subdomains are adjacent to that vertex.

Definition at line 340 of file grid_tools_cache.cc.

get_triangulation()

template<int dim, int spacedim>

const Triangulation< dim, spacedim > & GridTools::Cache< dim, spacedim >::get_triangulation ( ) const

inline

Return a reference to the stored triangulation.

Definition at line 347 of file grid_tools_cache.h.

get_mapping()

template<int dim, int spacedim>

const Mapping< dim, spacedim > & GridTools::Cache< dim, spacedim >::get_mapping ( ) const

inline

Return a reference to the stored mapping.

Definition at line 356 of file grid_tools_cache.h.

get_covering_rtree()

template<int dim, int spacedim>

const RTree< std::pair< BoundingBox< spacedim >, unsigned int > > & GridTools::Cache< dim, spacedim >::get_covering_rtree

(

const unsigned int

level = 0

)

const

This function returns an object that allows identifying which process(es) in a parallel computation may own the cell that surrounds a given point. The elements of this object – an Rtree – are pairs of bounding boxes denoting areas that cover all or parts of the local portion of a parallel triangulation, and an unsigned int representing the process or subdomain that owns the cells falling within the given bounding box.

Given a point on a parallel::TriangulationBase, this tree allows to identify one, or few candidate processes, for which the point lies on a locally owned cell.

Constructing or updating the rtree requires a call to GridTools::build_global_description_tree(), which exchanges bounding boxes between all processes using Utilities::MPI::all_gather(), a collective operation. Therefore this function must be called by all processes at the same time.

The local bounding boxes are constructed by extracting the specified level from the rtree object returned by the get_locally_owned_cell_bounding_boxes_rtree(). Notice that level in this context does not refer to the level of the triangulation, but refer to the level of the RTree object (see, e.g., https://en.wikipedia.org/wiki/R-tree).

Definition at line 268 of file grid_tools_cache.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

update_flags

template<int dim, int spacedim = dim>

std::atomic<std::underlying_type_t<CacheUpdateFlags> > GridTools::Cache< dim, spacedim >::update_flags

mutableprivate

Keep track of what needs to be updated every time the triangulation is changed. Each of the get_*() functions above checks whether a data structure still needs to be updated before returning a reference to it; if it needs to be updated, it does so and resets the corresponding flag. The constructor as well as the signal slot that is called whenever the triangulation changes the re-sets this flag to update_all again.

The various get_() member functions may be reading and updating this variable from different threads, but are only ever reading or writing individual bits. We can make that thread-safe by using std::atomic with the correct integer type for the enum type of CacheUpdateFlags.

Definition at line 239 of file grid_tools_cache.h.

tria

template<int dim, int spacedim = dim>

ObserverPointer<const Triangulation<dim, spacedim>, Cache<dim, spacedim> > GridTools::Cache< dim, spacedim >::tria

private

A pointer to the Triangulation.

Definition at line 245 of file grid_tools_cache.h.

mapping

template<int dim, int spacedim = dim>

ObserverPointer<const Mapping<dim, spacedim>, Cache<dim, spacedim> > GridTools::Cache< dim, spacedim >::mapping

private

Mapping to use when computing on the Triangulation.

Definition at line 250 of file grid_tools_cache.h.

vertex_to_cells

template<int dim, int spacedim = dim>

std::vector< std::set<typename Triangulation<dim, spacedim>::active_cell_iterator> > GridTools::Cache< dim, spacedim >::vertex_to_cells

mutableprivate

Store vertex to cell map information, as generated by GridTools::vertex_to_cell_map()

Definition at line 259 of file grid_tools_cache.h.

vertex_to_cells_mutex

template<int dim, int spacedim = dim>

std::mutex GridTools::Cache< dim, spacedim >::vertex_to_cells_mutex

mutableprivate

Definition at line 260 of file grid_tools_cache.h.

vertex_to_cell_centers

template<int dim, int spacedim = dim>

std::vector<std::vector<Tensor<1, spacedim> > > GridTools::Cache< dim, spacedim >::vertex_to_cell_centers

mutableprivate

Store vertex to cell center directions, as generated by GridTools::vertex_to_cell_centers_directions().

Definition at line 267 of file grid_tools_cache.h.

vertex_to_cell_centers_mutex

template<int dim, int spacedim = dim>

std::mutex GridTools::Cache< dim, spacedim >::vertex_to_cell_centers_mutex

mutableprivate

Definition at line 268 of file grid_tools_cache.h.

covering_rtree

template<int dim, int spacedim = dim>

std::map<unsigned int, RTree<std::pair<BoundingBox<spacedim>, unsigned int> > > GridTools::Cache< dim, spacedim >::covering_rtree

mutableprivate

A collection of rtree objects covering the whole mesh.

Each entry of the map is constructed from the function extract_rtree_level() applied to the rtree returned by the function get_locally_owned_cell_bounding_boxes_rtree(), with the specified level in input.

Definition at line 280 of file grid_tools_cache.h.

covering_rtree_mutex

template<int dim, int spacedim = dim>

std::mutex GridTools::Cache< dim, spacedim >::covering_rtree_mutex

mutableprivate

Definition at line 281 of file grid_tools_cache.h.

used_vertices

template<int dim, int spacedim = dim>

std::map<unsigned int, Point<spacedim> > GridTools::Cache< dim, spacedim >::used_vertices

mutableprivate

Store the used vertices of the Triangulation, as generated by GridTools::extract_used_vertices().

Definition at line 287 of file grid_tools_cache.h.

used_vertices_mutex

template<int dim, int spacedim = dim>

std::mutex GridTools::Cache< dim, spacedim >::used_vertices_mutex

mutableprivate

Definition at line 288 of file grid_tools_cache.h.

used_vertices_rtree

template<int dim, int spacedim = dim>

RTree<std::pair<Point<spacedim>, unsigned int> > GridTools::Cache< dim, spacedim >::used_vertices_rtree

mutableprivate

Store an RTree object, containing the used vertices of the triangulation.

Definition at line 293 of file grid_tools_cache.h.

used_vertices_rtree_mutex

template<int dim, int spacedim = dim>

std::mutex GridTools::Cache< dim, spacedim >::used_vertices_rtree_mutex

mutableprivate

Definition at line 294 of file grid_tools_cache.h.

cell_bounding_boxes_rtree

template<int dim, int spacedim = dim>

RTree< std::pair<BoundingBox<spacedim>, typename Triangulation<dim, spacedim>::active_cell_iterator> > GridTools::Cache< dim, spacedim >::cell_bounding_boxes_rtree

mutableprivate

Store an RTree object, containing the bounding boxes of the cells of the triangulation.

Definition at line 303 of file grid_tools_cache.h.

cell_bounding_boxes_rtree_mutex

template<int dim, int spacedim = dim>

std::mutex GridTools::Cache< dim, spacedim >::cell_bounding_boxes_rtree_mutex

mutableprivate

Definition at line 304 of file grid_tools_cache.h.

locally_owned_cell_bounding_boxes_rtree

template<int dim, int spacedim = dim>

RTree< std::pair<BoundingBox<spacedim>, typename Triangulation<dim, spacedim>::active_cell_iterator> > GridTools::Cache< dim, spacedim >::locally_owned_cell_bounding_boxes_rtree

mutableprivate

Store an RTree object, containing the bounding boxes of the locally owned cells of the triangulation.

Definition at line 313 of file grid_tools_cache.h.

locally_owned_cell_bounding_boxes_rtree_mutex

template<int dim, int spacedim = dim>

std::mutex GridTools::Cache< dim, spacedim >::locally_owned_cell_bounding_boxes_rtree_mutex

mutableprivate

Definition at line 314 of file grid_tools_cache.h.

vertex_to_neighbor_subdomain

template<int dim, int spacedim = dim>

std::vector<std::set<unsigned int> > GridTools::Cache< dim, spacedim >::vertex_to_neighbor_subdomain

mutableprivate

Store an std::vector of std::set of integer containing the id of all subdomain to which a vertex is connected to.

Definition at line 320 of file grid_tools_cache.h.

vertex_to_neighbor_subdomain_mutex

template<int dim, int spacedim = dim>

std::mutex GridTools::Cache< dim, spacedim >::vertex_to_neighbor_subdomain_mutex

mutableprivate

Definition at line 321 of file grid_tools_cache.h.

vertices_with_ghost_neighbors

template<int dim, int spacedim = dim>

std::map<unsigned int, std::set<::types::subdomain_id> > GridTools::Cache< dim, spacedim >::vertices_with_ghost_neighbors

mutableprivate

Store an std::map of unsigned integer containing the set of subdomains connected to each vertex.

Definition at line 328 of file grid_tools_cache.h.

vertices_with_ghost_neighbors_mutex

template<int dim, int spacedim = dim>

std::mutex GridTools::Cache< dim, spacedim >::vertices_with_ghost_neighbors_mutex

mutableprivate

Definition at line 329 of file grid_tools_cache.h.

tria_change_signal

template<int dim, int spacedim = dim>

boost::signals2::connection GridTools::Cache< dim, spacedim >::tria_change_signal

private

Storage for the status of the triangulation change signal.

Definition at line 334 of file grid_tools_cache.h.

tria_create_signal

template<int dim, int spacedim = dim>

boost::signals2::connection GridTools::Cache< dim, spacedim >::tria_create_signal

private

Storage for the status of the triangulation creation signal.

Definition at line 339 of file grid_tools_cache.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 files:

• include/deal.II/base/mpi_remote_point_evaluation.h
• include/deal.II/grid/grid_tools_cache.h
• source/grid/grid_tools_cache.cc