Mesh geometric partitioning service. More...

Inheritance diagram for Arcane::ArcaneGeometricMeshPartitionerService:

Collaboration diagram for Arcane::ArcaneGeometricMeshPartitionerService:

Public Member Functions
	ArcaneGeometricMeshPartitionerService (const ServiceBuildInfo &sbi)
IMesh *	mesh () const override
	Mesh associated with the partitioner.
void	build () override
	Build-level construction of the service.
void	partitionMesh (bool initial_partition) override
void	partitionMesh (bool initial_partition, Int32 nb_part) override
void	notifyEndPartition () override
	Notification when a re-partitioning finishes (after entity exchange).
void	setMaximumComputationTime (Real v) override
	Sets the proportion of computation time.
Real	maximumComputationTime () const override
void	setComputationTimes (RealConstArrayView v) override
	Computation time of this subdomain. The first element indicates the computation time of the subdomain corresponding to calculations whose cost is proportional to the cells. The following must be associated with a variable (to be done).
RealConstArrayView	computationTimes () const override
void	setImbalance (Real v) override
	Sets the computation time imbalance.
Real	imbalance () const override
	Computation time imbalance.
void	setMaxImbalance (Real v) override
	Sets the maximum allowed imbalance.
Real	maxImbalance () const override
	Maximum allowed imbalance.
ArrayView< float >	cellsWeight () const override
void	setCellsWeight (ArrayView< float > weights, Integer nb_weight) override
	Allows defining the weights of objects to be partitioned: ILoadBalanceMng must now be used.
void	setILoadBalanceMng (ILoadBalanceMng *) override
	Changes the ILoadBalanceMng to use.
ILoadBalanceMng *	loadBalanceMng () const override
Public Member Functions inherited from Arcane::ArcaneArcaneGeometricMeshPartitionerServiceObject
	ArcaneArcaneGeometricMeshPartitionerServiceObject (const Arcane::ServiceBuildInfo &sbi)
	Constructeur.
virtual	~ArcaneArcaneGeometricMeshPartitionerServiceObject ()
	Destructeur.
CaseOptionsArcaneGeometricMeshPartitionerService *	options () const
	Options du jeu de données du service.
Public Member Functions inherited from Arcane::BasicService
	~BasicService () override
	Releases resources.
virtual ISubDomain *	subDomain ()
Public Member Functions inherited from Arcane::AbstractService
	~AbstractService () override
	Destructor.
IServiceInfo *	serviceInfo () const override
	Access to service information. See IServiceInfo for details.
IBase *	serviceParent () const override
	Access to the base interface of main Arcane objects.
IService *	serviceInterface () override
	Returns the low-level IService interface of the service.
Public Member Functions inherited from Arcane::TraceAccessor
	TraceAccessor (ITraceMng *m)
	Constructs an accessor via the trace manager m.
	TraceAccessor (const TraceAccessor &rhs)
	Copy constructor.
TraceAccessor &	operator= (const TraceAccessor &rhs)
	Copy assignment operator.
virtual	~TraceAccessor ()
	Frees resources.
ITraceMng *	traceMng () const
	Trace manager.
TraceMessage	info () const
	Flow for an information message.
TraceMessage	pinfo () const
	Flow for a parallel information message.
TraceMessage	info (char category) const
	Flow for an information message of a given category.
TraceMessage	pinfo (char category) const
	Flow for a parallel information message of a given category.
TraceMessage	info (bool v) const
	Flow for an information message.
TraceMessage	warning () const
	Flow for a warning message.
TraceMessage	pwarning () const
TraceMessage	error () const
	Flow for an error message.
TraceMessage	perror () const
TraceMessage	log () const
	Flow for a log message.
TraceMessage	plog () const
	Flow for a log message.
TraceMessage	logdate () const
	Flow for a log message preceded by the date.
TraceMessage	fatal () const
	Flow for a fatal error message.
TraceMessage	pfatal () const
	Flow for a parallel fatal error message.
TraceMessageDbg	debug (Trace::eDebugLevel=Trace::Medium) const
	Flow for a debug message.
Trace::eDebugLevel	configDbgLevel () const
	Debug level of the configuration file.
TraceMessage	info (Int32 verbose_level) const
	Flow for an information message of a given level.
TraceMessage	linfo () const
	Flow for an information message with the local information level of this instance.
TraceMessage	linfo (Int32 relative_level) const
	Flow for an information message with the local information level of this instance.
void	fatalMessage (const StandaloneTraceMessage &o) const
Public Member Functions inherited from Arcane::IService
virtual	~IService ()
	Releases resources.
Public Member Functions inherited from Arcane::MeshAccessor
	MeshAccessor (ISubDomain *sd)
	MeshAccessor (IMesh *mesh)
	MeshAccessor (const MeshHandle &mesh_handle)
Integer	nbCell () const
	Returns the number of cells in the mesh.
Integer	nbFace () const
	Returns the number of faces in the mesh.
Integer	nbEdge () const
	Returns the number of edges in the mesh.
Integer	nbNode () const
	Returns the number of nodes in the mesh.
VariableNodeReal3 &	nodesCoordinates () const
	Returns the coordinates of the mesh nodes.
NodeGroup	allNodes () const
	Returns the group containing all nodes.
EdgeGroup	allEdges () const
	Returns the group containing all edges.
FaceGroup	allFaces () const
	Returns the group containing all faces.
CellGroup	allCells () const
	Returns the group containing all cells.
FaceGroup	outerFaces () const
	Returns the group containing all boundary faces.
NodeGroup	ownNodes () const
	Returns the group containing all nodes specific to this domain.
CellGroup	ownCells () const
	Returns the group containing all cells specific to this domain.
FaceGroup	ownFaces () const
	Group containing all faces specific to this domain.
EdgeGroup	ownEdges () const
	Group containing all edges specific to this domain.
IMesh *	mesh () const
const MeshHandle &	meshHandle () const
Public Member Functions inherited from Arcane::CommonVariables
	CommonVariables (IModule *c)
	Constructs the references of the common variables for the module c.
	CommonVariables (IVariableMng *variable_mng)
	Constructs the references of the common variables for the manager variable_mng.
	CommonVariables (ISubDomain *sd)
	Constructs the references of the common variables for the subdomain sd.
virtual	~CommonVariables ()
	Releases resources.
Int32	globalIteration () const
	Current iteration number.
Real	globalTime () const
	Current time.
Real	globalOldTime () const
	Previous current time.
Real	globalFinalTime () const
	Final time of the simulation.
Real	globalDeltaT () const
	Current Delta T.
Real	globalCPUTime () const
	CPU time used (in seconds).
Real	globalOldCPUTime () const
	Previous CPU time used (in seconds).
Real	globalElapsedTime () const
	Clock time (elapsed) used (in seconds).
Real	globalOldElapsedTime () const
	Previous clock time (elapsed) used (in seconds).
Public Member Functions inherited from Arcane::IMeshPartitioner
virtual IPrimaryMesh *	primaryMesh () override
	Associated mesh.
virtual void	partitionMesh (bool initial_partition)=0
Public Member Functions inherited from Arcane::IMeshPartitionerBase
virtual	~IMeshPartitionerBase ()=default
	Releases resources.

Private Member Functions
Real3	_computeBarycenter (const VariableCellReal3 &cells_center, CellVectorView cells)
Real3x3	_computeInertiaTensor (Real3 center, const VariableCellReal3 &cells_center, CellVectorView cells)
Real3	_findPrincipalAxis (Real3x3 tensor)
void	_partitionMesh2 ()
void	_partitionMesh (bool initial_partition, Int32 nb_part)
bool	_partitionMeshRecursive (const VariableCellReal3 &cells_center, CellVectorView cells, Int32 partition_index, Int32 &part_id)
void	_partitionMeshRecursive2 (ConstArrayView< BinaryTree::TreeNode > tree_nodes, const VariableCellReal3 &cells_center, CellVectorView cells, Int32 partition_index)
void	_printOwners ()
Real3	_computeEigenValuesAndVectors (ITraceMng *tm, Real3x3 tensor, Real3x3 &eigen_vectors, Real3 &eigen_values)

Private Attributes
Real	m_imbalance = 0.0
Real	m_max_imbalance = 0.0
Real	m_max_computation_time = 0.0
Int32	m_nb_weight = 0
ArrayView< float >	m_cells_weight
UniqueArray< Real >	m_computation_times
Int32	m_nb_part = 0

Additional Inherited Members
Static Public Member Functions inherited from Arcane::ArcaneArcaneGeometricMeshPartitionerServiceObject
template<typename ServiceClassType>
static void	fillServiceInfo (Arcane::ServiceInfo *si)
Public Attributes inherited from Arcane::CommonVariables
VariableScalarInt32	m_global_iteration
	Current iteration.
VariableScalarReal	m_global_time
	Current time.
VariableScalarReal	m_global_deltat
	Global Delta T.
VariableScalarReal	m_global_old_time
	Time previous to the current time.
VariableScalarReal	m_global_old_deltat
	Delta T at the time previous to the global time.
VariableScalarReal	m_global_final_time
	Final time of the case.
VariableScalarReal	m_global_old_cpu_time
	Previous CPU time used (in seconds).
VariableScalarReal	m_global_cpu_time
	CPU time used (in seconds).
VariableScalarReal	m_global_old_elapsed_time
	Previous clock time used (in seconds).
VariableScalarReal	m_global_elapsed_time
	Clock time used (in seconds).
Protected Member Functions inherited from Arcane::BasicService
	BasicService (const ServiceBuildInfo &)
Protected Member Functions inherited from Arcane::AbstractService
	AbstractService (const ServiceBuildInfo &)
	Constructor from a ServiceBuildInfo.
Protected Member Functions inherited from Arcane::TraceAccessor
void	_setLocalVerboseLevel (Int32 v)
Int32	_localVerboseLevel () const
Protected Member Functions inherited from Arcane::IService
	IService ()
	Constructor.

Detailed Description

Mesh geometric partitioning service.

This service allows performing a geometric partitioning. Its primary goal is to allow parallel tests even if no specific partitioning service (like ParMetis) is available.

The algorithm is as follows:

The partitioning is recursive, and at each iteration, a partition is split into two.
To split a partition, the center of gravity of the partition, as well as the inertia tensor matrix, is calculated.
From this matrix, the eigenvector corresponding to the smallest axis (the one corresponding to the smallest eigenvalue) is taken.
The center of gravity and the eigenvector define a plane (or a line in 2D) which serves as a partition: elements on one side of the plane are in one partition and those on the other side are in another.
This mechanism is applied to cut into the desired number of partitions.

The current algorithm and implementation are very simple and have the following limitations:

Element weights are not taken into account when calculating the partitioning
It is assumed that the number of partitions is a power of 2. If not, some partitions will be larger than others. For example, if we want to split into 3, we first create two identical partitions 1 and 2, then split partition 2 into two parts. Partition 1 will therefore theoretically be twice as large as partitions 2 and 3.
The partition is done according to a plane, which is probably not optimal for limiting the boundary. Using a circle would be more sensible.
The implementation is linear in the number of partitions and all ranks participate. Normally, if we want P partitions, then the number of recursions is N=log2(P) and it would be possible to perform all partitions of rank 1 to N simultaneously.

Currently, the algorithm used applies to cells, but only coordinates are used, which would allow it to be applied without mesh elements. This could be useful for an initial partitioning such as the one used in the parallel MSH reader.

Definition at line 332 of file ArcaneGeometricMeshPartitionerService.cc.

Constructor & Destructor Documentation

◆ ArcaneGeometricMeshPartitionerService()

Arcane::ArcaneGeometricMeshPartitionerService::ArcaneGeometricMeshPartitionerService ( const ServiceBuildInfo & sbi )

explicit

Definition at line 410 of file ArcaneGeometricMeshPartitionerService.cc.

Member Function Documentation

◆ _computeBarycenter()

Real3 Arcane::ArcaneGeometricMeshPartitionerService::_computeBarycenter	(	const VariableCellReal3 &	cells_center,
		CellVectorView	cells )

private

Definition at line 420 of file ArcaneGeometricMeshPartitionerService.cc.

◆ _computeInertiaTensor()

Real3x3 Arcane::ArcaneGeometricMeshPartitionerService::_computeInertiaTensor	(	Real3	center,
		const VariableCellReal3 &	cells_center,
		CellVectorView	cells )

private

Definition at line 443 of file ArcaneGeometricMeshPartitionerService.cc.

◆ _findPrincipalAxis()

Real3 Arcane::ArcaneGeometricMeshPartitionerService::_findPrincipalAxis ( Real3x3 tensor )

private

Definition at line 479 of file ArcaneGeometricMeshPartitionerService.cc.

◆ _partitionMesh()

void Arcane::ArcaneGeometricMeshPartitionerService::_partitionMesh	(	bool	initial_partition,
		Int32	nb_part )

private

Definition at line 820 of file ArcaneGeometricMeshPartitionerService.cc.

◆ _partitionMesh2()

void Arcane::ArcaneGeometricMeshPartitionerService::_partitionMesh2 ( )

private

Definition at line 506 of file ArcaneGeometricMeshPartitionerService.cc.

◆ _partitionMeshRecursive()

bool Arcane::ArcaneGeometricMeshPartitionerService::_partitionMeshRecursive	(	const VariableCellReal3 &	cells_center,
		CellVectorView	cells,
		Int32	partition_index,
		Int32 &	part_id )

private

Definition at line 548 of file ArcaneGeometricMeshPartitionerService.cc.

◆ _partitionMeshRecursive2()

void Arcane::ArcaneGeometricMeshPartitionerService::_partitionMeshRecursive2	(	ConstArrayView< BinaryTree::TreeNode >	tree_nodes,
		const VariableCellReal3 &	cells_center,
		CellVectorView	cells,
		Int32	partition_index )

private

Definition at line 627 of file ArcaneGeometricMeshPartitionerService.cc.

◆ _printOwners()

void Arcane::ArcaneGeometricMeshPartitionerService::_printOwners ( )

private

Definition at line 849 of file ArcaneGeometricMeshPartitionerService.cc.

◆ build()

void Arcane::ArcaneGeometricMeshPartitionerService::build ( void )

inlineoverridevirtual

Build-level construction of the service.

This method is called right after the constructor.

Reimplemented from Arcane::AbstractService.

Definition at line 343 of file ArcaneGeometricMeshPartitionerService.cc.

◆ cellsWeight()

ArrayView< float > Arcane::ArcaneGeometricMeshPartitionerService::cellsWeight ( ) const

inlineoverridevirtual

Implements Arcane::IMeshPartitioner.

Definition at line 363 of file ArcaneGeometricMeshPartitionerService.cc.

◆ computationTimes()

RealConstArrayView Arcane::ArcaneGeometricMeshPartitionerService::computationTimes ( ) const

inlineoverridevirtual

Implements Arcane::IMeshPartitioner.

Definition at line 357 of file ArcaneGeometricMeshPartitionerService.cc.

◆ imbalance()

Real Arcane::ArcaneGeometricMeshPartitionerService::imbalance ( ) const

inlineoverridevirtual

Computation time imbalance.

Implements Arcane::IMeshPartitioner.

Definition at line 359 of file ArcaneGeometricMeshPartitionerService.cc.

◆ loadBalanceMng()

ILoadBalanceMng * Arcane::ArcaneGeometricMeshPartitionerService::loadBalanceMng ( ) const

inlineoverridevirtual

Implements Arcane::IMeshPartitioner.

Definition at line 376 of file ArcaneGeometricMeshPartitionerService.cc.

◆ maxImbalance()

Real Arcane::ArcaneGeometricMeshPartitionerService::maxImbalance ( ) const

inlineoverridevirtual

Maximum allowed imbalance.

Implements Arcane::IMeshPartitioner.

Definition at line 361 of file ArcaneGeometricMeshPartitionerService.cc.

◆ maximumComputationTime()

Real Arcane::ArcaneGeometricMeshPartitionerService::maximumComputationTime ( ) const

inlineoverridevirtual

Implements Arcane::IMeshPartitioner.

Definition at line 355 of file ArcaneGeometricMeshPartitionerService.cc.

◆ mesh()

IMesh * Arcane::ArcaneGeometricMeshPartitionerService::mesh ( ) const

inlineoverridevirtual

Mesh associated with the partitioner.

Implements Arcane::IMeshPartitioner.

Definition at line 342 of file ArcaneGeometricMeshPartitionerService.cc.

Referenced by partitionMesh().

Here is the caller graph for this function:

◆ notifyEndPartition()

void Arcane::ArcaneGeometricMeshPartitionerService::notifyEndPartition ( )

inlineoverridevirtual

Notification when a re-partitioning finishes (after entity exchange).

Implements Arcane::IMeshPartitionerBase.

Definition at line 350 of file ArcaneGeometricMeshPartitionerService.cc.

◆ partitionMesh() [1/2]

void Arcane::ArcaneGeometricMeshPartitionerService::partitionMesh ( bool initial_partition )

overridevirtual

Re-partitions the mesh mesh

This method changes the owners of the entities and fills the IItemFamily::itemsNewOwner() variable of each entity family of the mesh mesh with the number of the new owning subdomain.

Note: This method is reserved for Arcane developers. If a module wishes to perform a re-partitioning, it must call the method IMeshUtilities::partitionAndExchangeMeshWithReplication() which handles both the partitioning and the exchange of information and supports domain replication.

Implements Arcane::IMeshPartitionerBase.

Definition at line 867 of file ArcaneGeometricMeshPartitionerService.cc.

References mesh().

Here is the call graph for this function:

◆ partitionMesh() [2/2]

void Arcane::ArcaneGeometricMeshPartitionerService::partitionMesh	(	bool	initial_partition,
		Int32	nb_part )

inlineoverridevirtual

Implements Arcane::IMeshPartitioner.

Definition at line 345 of file ArcaneGeometricMeshPartitionerService.cc.

◆ setCellsWeight()

void Arcane::ArcaneGeometricMeshPartitionerService::setCellsWeight	(	ArrayView< float >	weights,
		Integer	nb_weight )

inlineoverridevirtual

Allows defining the weights of objects to be partitioned: ILoadBalanceMng must now be used.

Implements Arcane::IMeshPartitioner.

Definition at line 365 of file ArcaneGeometricMeshPartitionerService.cc.

◆ setComputationTimes()

void Arcane::ArcaneGeometricMeshPartitionerService::setComputationTimes ( RealConstArrayView v )

inlineoverridevirtual

Computation time of this subdomain. The first element indicates the computation time of the subdomain corresponding to calculations whose cost is proportional to the cells. The following must be associated with a variable (to be done).

Implements Arcane::IMeshPartitioner.

Definition at line 356 of file ArcaneGeometricMeshPartitionerService.cc.