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//======================================================================================================================
//
// This file is part of waLBerla. waLBerla is free software: you can
// redistribute it and/or modify it under the terms of the GNU General Public
// License as published by the Free Software Foundation, either version 3 of
// the License, or (at your option) any later version.
//
// waLBerla is distributed in the hope that it will be useful, but WITHOUT
// ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
// FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
// for more details.
//
// You should have received a copy of the GNU General Public License along
// with waLBerla (see COPYING.txt). If not, see <http://www.gnu.org/licenses/>.
//
//! \file Initialization.cpp
//! \ingroup blockforest
//! \author Florian Schornbaum <florian.schornbaum@fau.de>
//
//======================================================================================================================
#include "BlockNeighborhoodSection.h"
#include "Initialization.h"
#include "SetupBlockForest.h"
#include "loadbalancing/Cartesian.h"
#include "core/Abort.h"
#include "core/cell/CellInterval.h"
#include "core/math/IntegerFactorization.h"
#include "core/mpi/MPIManager.h"
#include "stencil/D3Q19.h"

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namespace walberla {
namespace blockforest {
//**********************************************************************************************************************
/*!
* Parses config block called 'DomainSetup' and creates a StructuredBlockForest
*
* For more information see function below.
*/
//**********************************************************************************************************************
shared_ptr< StructuredBlockForest > createUniformBlockGridFromConfig( const shared_ptr< Config > & config,
CellInterval * requestedDomainSize,
const bool keepGlobalBlockInformation )
{
if( !!config )
{
auto block = config->getGlobalBlock();
if( block ) {
auto subBlock = block.getBlock( "DomainSetup" );
if ( ! subBlock ) {
WALBERLA_ABORT_NO_DEBUG_INFO( "Unable to create uniform block grid from configuration file."
"\nDid you forget to specify a \"DomainSetup\" block in the configuration file?" );
}
return createUniformBlockGridFromConfig( subBlock, requestedDomainSize, keepGlobalBlockInformation );
}
}
WALBERLA_ABORT_NO_DEBUG_INFO( "No Configuration specified" );
return shared_ptr<StructuredBlockForest>();
}
//**********************************************************************************************************************
/*!
* \brief Parses config block and creates a StructuredBlockForest
*
* Two possibilities:
* 1) Using the cells per block and number of blocks for each direction
\verbatim
{
cellsPerBlock < 10, 20, 30 > ; // required
blocks < 1, 2, 3 > ; // required
periodic < 0, 0, 1 >; // not required, defaults to no periodicity
dx 0.01; // defaults to 1.0
}
\endverbatim
* An optional config parameter 'cartesianSetup' is available. Its default, true, causes one block to be
* assigned to each process. Setting it to false allows multiple blocks to be assigned to each process.
* If the number of blocks is not divisble by the number of processes, the loadbalancer tries to assign
* the blocks to processes as evenly as possible.

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* 2) Using the number of global cells, #blocks = #processes, if this does not fit, extend the domain
\verbatim
{
cells < 10,40,90>; // required
periodic < 0, 0, 1 >; // not required, defaults to no periodicity
dx 0.01; // defaults to 1.0
}
\endverbatim
* An optional config parameter 'oneBlockPerProcess' is available. Setting it to false forces all
* blocks to be assigned to a single process, which may be useful for debugging purposes. Otherwise,
* one block is assigned to each process.

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* Example: cells < 31,31,31> started using 8 processors <BR>
* calculated processor distribution <2,2,2> <BR>
* real domain is then extended to <32,32,32> and every processor gets a block of <16,16,16>
*
* When this setup is used and requestedDomainSize is not the null pointer, it is set to <BR>
* the requested domain size ( in the example <31,31,31> )
*
*/
//**********************************************************************************************************************
shared_ptr< StructuredBlockForest > createUniformBlockGridFromConfig( const Config::BlockHandle & configBlock,
CellInterval * requestedDomainSize,
const bool keepGlobalBlockInformation )
{
const Vector3<bool> periodic = configBlock.getParameter<Vector3<bool> >( "periodic", Vector3<bool> (false) );
const real_t dx = configBlock.getParameter<real_t >( "dx", real_t(1) );
Vector3<uint_t> cellsPerBlock;
Vector3<uint_t> blocks;
if ( configBlock.isDefined("cells") )
{
if ( configBlock.isDefined("cellsPerBlock") || configBlock.isDefined("blocks") )
WALBERLA_ABORT_NO_DEBUG_INFO("Config Error: Use either ('cellsPerBlock' and 'blocks') or 'cells', not both!");
Vector3<uint_t> cells = configBlock.getParameter<Vector3<uint_t> >( "cells" );
if ( requestedDomainSize )
*requestedDomainSize = CellInterval( 0,0,0,
cell_idx_c(cells[0])-1,
cell_idx_c(cells[1])-1,
cell_idx_c(cells[2])-1 );
uint_t nrOfProcesses = uint_c( MPIManager::instance()->numProcesses() );
calculateCellDistribution( cells, nrOfProcesses, blocks, cellsPerBlock );
}
else
{
cellsPerBlock = configBlock.getParameter<Vector3<uint_t> >( "cellsPerBlock" );
blocks = configBlock.getParameter<Vector3<uint_t> >( "blocks" );
if ( requestedDomainSize )
*requestedDomainSize = CellInterval( 0, 0, 0, cell_idx_c( cellsPerBlock[0] * blocks[0] ),
cell_idx_c( cellsPerBlock[1] * blocks[1] ),
cell_idx_c( cellsPerBlock[2] * blocks[2] ) );
}
const bool oneBlockPerProcess = configBlock.getParameter<bool> ( "oneBlockPerProcess", true );
const bool cartesian = configBlock.getParameter<bool> ( "cartesianSetup", true );
if ( !cartesian )
{
if ( configBlock.isDefined("oneBlockPerProcess") )
WALBERLA_ABORT_NO_DEBUG_INFO("Config Error: Set either 'oneBlockPerProcess' or set 'cartesianSetup' to false, not both!");
return createUniformBlockGrid(
blocks[0], blocks[1], blocks[2], // blocks in x/y/z direction
cellsPerBlock[0], cellsPerBlock[1], cellsPerBlock[2], // cells per block in x/y/z direction
dx, // cell size
uint_t(0), // maximum number of blocks per process
true, false, // include but don't force Metis
periodic[0], periodic[1], periodic[2], // periodicity
keepGlobalBlockInformation // keep global block information
);
}

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return createUniformBlockGrid(
blocks[0], blocks[1], blocks[2], // blocks/processes in x/y/z direction
cellsPerBlock[0], cellsPerBlock[1], cellsPerBlock[2], // cells per block in x/y/z direction
dx, // cell size
oneBlockPerProcess, // one block per process
periodic[0], periodic[1], periodic[2], // periodicity
keepGlobalBlockInformation // keep global block information
);
}
//**********************************************************************************************************************
/*!
* \brief Function for creating a block forest that represents a uniform block grid.
*
* Uniform block grid: Cartesian domain decomposition into blocks, each block has the same size.
* The distribution of blocks to processes also follows a Cartesian decomposition.
*
* \param domainAABB An axis-aligned bounding box that spans the entire simulation space/domain
* \param numberOfXBlocks Number of blocks in x direction
* \param numberOfYBlocks Number of blocks in y direction
* \param numberOfZBlocks Number of blocks in z direction
* \param numberOfXProcesses Number of processes the blocks are distributed to in x direction
* \param numberOfYProcesses Number of processes the blocks are distributed to in y direction
* \param numberOfZProcesses Number of processes the blocks are distributed to in z direction
* \param xPeriodic If true, the block structure is periodic in x direction [false by default]
* \param yPeriodic If true, the block structure is periodic in y direction [false by default]
* \param zPeriodic If true, the block structure is periodic in z direction [false by default]
* \param keepGlobalBlockInformation If true, each process keeps information about remote blocks (blocks that reside
* on other processes). This information includes the process rank, the state, and
* the axis-aligned bounding box of any block (local or remote). [false by default]
*/
//**********************************************************************************************************************
shared_ptr< BlockForest >
createBlockForest( const AABB& domainAABB,
const uint_t numberOfXBlocks, const uint_t numberOfYBlocks, const uint_t numberOfZBlocks,
const uint_t numberOfXProcesses, const uint_t numberOfYProcesses, const uint_t numberOfZProcesses,
const bool xPeriodic /* = false */, const bool yPeriodic /* = false */, const bool zPeriodic /* = false */,
const bool keepGlobalBlockInformation /* = false */ ) {
const uint_t numberOfProcesses = numberOfXProcesses * numberOfYProcesses * numberOfZProcesses;
if( numeric_cast< int >( numberOfProcesses ) != MPIManager::instance()->numProcesses() )
WALBERLA_ABORT( "The number of requested processes (" << numberOfProcesses << ") doesn't match the number "
"of active MPI processes (" << MPIManager::instance()->numProcesses() << ")!" );
// initialize SetupBlockForest = determine domain decomposition
SetupBlockForest sforest;
sforest.addWorkloadMemorySUIDAssignmentFunction( uniformWorkloadAndMemoryAssignment );
sforest.init( domainAABB, numberOfXBlocks, numberOfYBlocks, numberOfZBlocks, xPeriodic, yPeriodic, zPeriodic );
// if possible, create Cartesian MPI communicator
std::vector< uint_t >* processIdMap = nullptr;

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WALBERLA_MPI_SECTION()
{
auto mpiManager = MPIManager::instance();
//create cartesian communicator only if not yet a cartesian communicator (or other communicator was created)
if ( ! mpiManager->rankValid() )
{
if ( mpiManager->isCartesianCommValid() ) {
mpiManager->createCartesianComm( numberOfXProcesses, numberOfYProcesses, numberOfZProcesses, xPeriodic, yPeriodic, zPeriodic );

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processIdMap = new std::vector< uint_t >( numberOfProcesses );

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for( uint_t z = 0; z != numberOfZProcesses; ++z ) {
for( uint_t y = 0; y != numberOfYProcesses; ++y ) {
for( uint_t x = 0; x != numberOfXProcesses; ++x ) {

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(*processIdMap)[ z * numberOfXProcesses * numberOfYProcesses + y * numberOfXProcesses + x ] =
uint_c( MPIManager::instance()->cartesianRank(x,y,z) );
}

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}
}
}
else {
WALBERLA_LOG_WARNING_ON_ROOT( "Your version of OpenMPI contains a bug. See waLBerla issue #73 for more "
"information. As a workaround, MPI_COMM_WORLD instead of a "
"Cartesian MPI communicator is used." );
mpiManager->useWorldComm();
}

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}
}
// calculate process distribution
sforest.balanceLoad( blockforest::CartesianDistribution( numberOfXProcesses, numberOfYProcesses, numberOfZProcesses, processIdMap ),
numberOfXProcesses * numberOfYProcesses * numberOfZProcesses );
if( processIdMap != nullptr ) delete processIdMap;

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// create StructuredBlockForest (encapsulates a newly created BlockForest)
return std::make_shared< BlockForest >( uint_c( MPIManager::instance()->rank() ), sforest, keepGlobalBlockInformation );

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}
//**********************************************************************************************************************
/*!
* \brief Function for creating a structured block forest that represents a uniform block grid.
*
* Uniform block grid: Cartesian domain decomposition into blocks of cells, each block has the same size and contains
* the same number of cells.
* The distribution of blocks to processes also follows a Cartesian decomposition.
*
* \param domainAABB An axis-aligned bounding box that spans the entire simulation space/domain
* \param numberOfXBlocks Number of blocks in x direction
* \param numberOfYBlocks Number of blocks in y direction
* \param numberOfZBlocks Number of blocks in z direction
* \param numberOfXCellsPerBlock Number of cells of each block in x direction
* \param numberOfYCellsPerBlock Number of cells of each block in y direction
* \param numberOfZCellsPerBlock Number of cells of each block in z direction
* \param numberOfXProcesses Number of processes the blocks are distributed to in x direction
* \param numberOfYProcesses Number of processes the blocks are distributed to in y direction
* \param numberOfZProcesses Number of processes the blocks are distributed to in z direction
* \param xPeriodic If true, the block structure is periodic in x direction [false by default]
* \param yPeriodic If true, the block structure is periodic in y direction [false by default]
* \param zPeriodic If true, the block structure is periodic in z direction [false by default]
* \param keepGlobalBlockInformation If true, each process keeps information about remote blocks (blocks that reside
* on other processes). This information includes the process rank, the state, and
* the axis-aligned bounding box of any block (local or remote). [false by default]
*/
//**********************************************************************************************************************
shared_ptr< StructuredBlockForest >
createUniformBlockGrid( const AABB& domainAABB,
const uint_t numberOfXBlocks, const uint_t numberOfYBlocks, const uint_t numberOfZBlocks,
const uint_t numberOfXCellsPerBlock, const uint_t numberOfYCellsPerBlock, const uint_t numberOfZCellsPerBlock,
const uint_t numberOfXProcesses, const uint_t numberOfYProcesses, const uint_t numberOfZProcesses,
const bool xPeriodic /* = false */, const bool yPeriodic /* = false */, const bool zPeriodic /* = false */,
const bool keepGlobalBlockInformation /* = false */ )
{
auto bf = createBlockForest(
domainAABB,
numberOfXBlocks,
numberOfYBlocks,
numberOfZBlocks,
numberOfXProcesses,
numberOfYProcesses,
numberOfZProcesses,
xPeriodic,
yPeriodic,
zPeriodic,
keepGlobalBlockInformation);
auto sbf = std::make_shared< StructuredBlockForest >( bf, numberOfXCellsPerBlock, numberOfYCellsPerBlock, numberOfZCellsPerBlock );

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sbf->createCellBoundingBoxes();
return sbf;
}
//**********************************************************************************************************************
/*!
* \brief Function for creating a structured block forest that represents a uniform block grid.
*
* Uniform block grid: Cartesian domain decomposition into blocks of cells, each block has the same size and contains
* the same number of cells.
* The distribution of blocks to processes also follows a Cartesian decomposition.
*
* \param numberOfXBlocks Number of blocks in x direction
* \param numberOfYBlocks Number of blocks in y direction
* \param numberOfZBlocks Number of blocks in z direction
* \param numberOfXCellsPerBlock Number of cells of each block in x direction
* \param numberOfYCellsPerBlock Number of cells of each block in y direction
* \param numberOfZCellsPerBlock Number of cells of each block in z direction
* \param dx Edge length of each cell (cells are assumed to be cubes)
* \param numberOfXProcesses Number of processes the blocks are distributed to in x direction
* \param numberOfYProcesses Number of processes the blocks are distributed to in y direction
* \param numberOfZProcesses Number of processes the blocks are distributed to in z direction
* \param xPeriodic If true, the block structure is periodic in x direction [false by default]
* \param yPeriodic If true, the block structure is periodic in y direction [false by default]
* \param zPeriodic If true, the block structure is periodic in z direction [false by default]
* \param keepGlobalBlockInformation If true, each process keeps information about remote blocks (blocks that reside
* on other processes). This information includes the process rank, the state, and
* the axis-aligned bounding box of any block (local or remote). [false by default]
*/
//**********************************************************************************************************************
shared_ptr< StructuredBlockForest >
createUniformBlockGrid( const uint_t numberOfXBlocks, const uint_t numberOfYBlocks, const uint_t numberOfZBlocks,
const uint_t numberOfXCellsPerBlock, const uint_t numberOfYCellsPerBlock, const uint_t numberOfZCellsPerBlock,
const real_t dx,
const uint_t numberOfXProcesses, const uint_t numberOfYProcesses, const uint_t numberOfZProcesses,
const bool xPeriodic /* = false */, const bool yPeriodic /* = false */, const bool zPeriodic /* = false */,
const bool keepGlobalBlockInformation /* = false */ ) {
return createUniformBlockGrid( AABB( real_c(0), real_c(0), real_c(0), dx * real_c( numberOfXBlocks * numberOfXCellsPerBlock ),
dx * real_c( numberOfYBlocks * numberOfYCellsPerBlock ),
dx * real_c( numberOfZBlocks * numberOfZCellsPerBlock ) ),
numberOfXBlocks, numberOfYBlocks, numberOfZBlocks,
numberOfXCellsPerBlock, numberOfYCellsPerBlock, numberOfZCellsPerBlock,
numberOfXProcesses, numberOfYProcesses, numberOfZProcesses,
xPeriodic, yPeriodic, zPeriodic, keepGlobalBlockInformation );
}
//**********************************************************************************************************************
/*!
* \brief Function for creating a structured block forest that represents a uniform block grid.
*
* Uniform block grid: Cartesian domain decomposition into blocks of cells, each block has the same size and contains
* the same number of cells.
* Either all blocks are assigned to the same process (useful for non-parallel simulations) or each blocks is assigned
* to a different process (useful if only one block shall be assigned to each process).
*
* \param domainAABB An axis-aligned bounding box that spans the entire simulation space/domain
* \param numberOfXBlocks Number of blocks in x direction
* \param numberOfYBlocks Number of blocks in y direction
* \param numberOfZBlocks Number of blocks in z direction
* \param numberOfXCellsPerBlock Number of cells of each block in x direction
* \param numberOfYCellsPerBlock Number of cells of each block in y direction
* \param numberOfZCellsPerBlock Number of cells of each block in z direction
* \param oneBlockPerProcess If true, each block is assigned to a different process. If false, all blocks are
* assigned to the same process (process 0).
* \param xPeriodic If true, the block structure is periodic in x direction [false by default]
* \param yPeriodic If true, the block structure is periodic in y direction [false by default]
* \param zPeriodic If true, the block structure is periodic in z direction [false by default]
* \param keepGlobalBlockInformation If true, each process keeps information about remote blocks (blocks that reside
* on other processes). This information includes the process rank, the state, and
* the axis-aligned bounding box of any block (local or remote). [false by default]
*/
//**********************************************************************************************************************
shared_ptr< StructuredBlockForest >
createUniformBlockGrid( const AABB& domainAABB,
const uint_t numberOfXBlocks, const uint_t numberOfYBlocks, const uint_t numberOfZBlocks,
const uint_t numberOfXCellsPerBlock, const uint_t numberOfYCellsPerBlock, const uint_t numberOfZCellsPerBlock,
const bool oneBlockPerProcess,
const bool xPeriodic /* = false */, const bool yPeriodic /* = false */, const bool zPeriodic /* = false */,
const bool keepGlobalBlockInformation /* = false */ ) {
if( oneBlockPerProcess )
return createUniformBlockGrid( domainAABB, numberOfXBlocks, numberOfYBlocks, numberOfZBlocks,
numberOfXCellsPerBlock, numberOfYCellsPerBlock, numberOfZCellsPerBlock,
numberOfXBlocks, numberOfYBlocks, numberOfZBlocks, xPeriodic, yPeriodic, zPeriodic, keepGlobalBlockInformation );
// all blocks on the same process
return createUniformBlockGrid( domainAABB, numberOfXBlocks, numberOfYBlocks, numberOfZBlocks,
numberOfXCellsPerBlock, numberOfYCellsPerBlock, numberOfZCellsPerBlock, uint_c(1), uint_c(1), uint_c(1),
xPeriodic, yPeriodic, zPeriodic, keepGlobalBlockInformation );
}
//**********************************************************************************************************************
/*!
* \brief Function for creating a structured block forest that represents a uniform block grid.
*
* Uniform block grid: Cartesian domain decomposition into blocks of cells, each block has the same size and contains
* the same number of cells.
* Either all blocks are assigned to the same process (useful for non-parallel simulations) or each blocks is assigned
* to a different process (useful if only one block shall be assigned to each process).
*
* \param numberOfXBlocks Number of blocks in x direction
* \param numberOfYBlocks Number of blocks in y direction
* \param numberOfZBlocks Number of blocks in z direction
* \param numberOfXCellsPerBlock Number of cells of each block in x direction
* \param numberOfYCellsPerBlock Number of cells of each block in y direction
* \param numberOfZCellsPerBlock Number of cells of each block in z direction
* \param dx Edge length of each cell (cells are assumed to be cubes)
* \param oneBlockPerProcess If true, each block is assigned to a different process. If false, all blocks are
* assigned to the same process (process 0).
* \param xPeriodic If true, the block structure is periodic in x direction [false by default]
* \param yPeriodic If true, the block structure is periodic in y direction [false by default]
* \param zPeriodic If true, the block structure is periodic in z direction [false by default]
* \param keepGlobalBlockInformation If true, each process keeps information about remote blocks (blocks that reside
* on other processes). This information includes the process rank, the state, and
* the axis-aligned bounding box of any block (local or remote). [false by default]
*/
//**********************************************************************************************************************
shared_ptr< StructuredBlockForest >
createUniformBlockGrid( const uint_t numberOfXBlocks, const uint_t numberOfYBlocks, const uint_t numberOfZBlocks,
const uint_t numberOfXCellsPerBlock, const uint_t numberOfYCellsPerBlock, const uint_t numberOfZCellsPerBlock,
const real_t dx,
const bool oneBlockPerProcess,
const bool xPeriodic /* = false */, const bool yPeriodic /* = false */, const bool zPeriodic /* = false */,
const bool keepGlobalBlockInformation /* = false */ ) {
return createUniformBlockGrid( AABB( real_c(0), real_c(0), real_c(0), dx * real_c( numberOfXBlocks * numberOfXCellsPerBlock ),
dx * real_c( numberOfYBlocks * numberOfYCellsPerBlock ),
dx * real_c( numberOfZBlocks * numberOfZCellsPerBlock ) ),
numberOfXBlocks, numberOfYBlocks, numberOfZBlocks,
numberOfXCellsPerBlock, numberOfYCellsPerBlock, numberOfZCellsPerBlock,
oneBlockPerProcess, xPeriodic, yPeriodic, zPeriodic, keepGlobalBlockInformation );
}
//**********************************************************************************************************************
/*!
* \brief Function for creating a structured block forest that represents a uniform block grid.
*
* Uniform block grid: Cartesian domain decomposition into blocks of cells, each block has the same size and contains
* the same number of cells.
* The number of active MPI processes is used in order to determine the process distribution = in order to perform the
* initial, static load balancing. Each block is assumed to generate the same amount of work and to require the same
* amount of memory.
*
* \param domainAABB An axis-aligned bounding box that spans the entire simulation space/domain
* \param numberOfXBlocks Number of blocks in x direction
* \param numberOfYBlocks Number of blocks in y direction
* \param numberOfZBlocks Number of blocks in z direction
* \param numberOfXCellsPerBlock Number of cells of each block in x direction
* \param numberOfYCellsPerBlock Number of cells of each block in y direction
* \param numberOfZCellsPerBlock Number of cells of each block in z direction
* \param maxBlocksPerProcess Maximum number of blocks that are allowed to be assigned to one process. If a
* value of '0' is provided, any number of blocks are allowed to be located on one
* process - meaning static load balancing doesn't try to obey any memory limit. ['0' by default]
* \param includeMetis If true (and if available!), METIS is also used during load balancing. [true by default]
* \param forceMetis If true, METIS is always preferred over space filling curves [false by default]
* \param xPeriodic If true, the block structure is periodic in x direction [false by default]
* \param yPeriodic If true, the block structure is periodic in y direction [false by default]
* \param zPeriodic If true, the block structure is periodic in z direction [false by default]
* \param keepGlobalBlockInformation If true, each process keeps information about remote blocks (blocks that reside
* on other processes). This information includes the process rank, the state, and
* the axis-aligned bounding box of any block (local or remote). [false by default]
*/
//**********************************************************************************************************************
shared_ptr< StructuredBlockForest >
createUniformBlockGrid( const AABB& domainAABB,
const uint_t numberOfXBlocks, const uint_t numberOfYBlocks, const uint_t numberOfZBlocks,
const uint_t numberOfXCellsPerBlock, const uint_t numberOfYCellsPerBlock, const uint_t numberOfZCellsPerBlock,
const uint_t maxBlocksPerProcess /*= 0*/, const bool includeMetis /*= true*/, const bool forceMetis /*= false*/,
const bool xPeriodic /*= false*/, const bool yPeriodic /*= false*/, const bool zPeriodic /*= false*/,
const bool keepGlobalBlockInformation /*= false*/ ) {
// initialize SetupBlockForest = determine domain decomposition
SetupBlockForest sforest;
sforest.addWorkloadMemorySUIDAssignmentFunction( uniformWorkloadAndMemoryAssignment );
sforest.init( domainAABB, numberOfXBlocks, numberOfYBlocks, numberOfZBlocks, xPeriodic, yPeriodic, zPeriodic );
// calculate process distribution
const memory_t memoryLimit = ( maxBlocksPerProcess == 0 ) ? numeric_cast< memory_t >( sforest.getNumberOfBlocks() ) :
numeric_cast< memory_t >( maxBlocksPerProcess );
GlobalLoadBalancing::MetisConfiguration< SetupBlock > metisConfig( includeMetis, forceMetis,
std::bind( cellWeightedCommunicationCost, std::placeholders::_1, std::placeholders::_2,

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numberOfXCellsPerBlock,
numberOfYCellsPerBlock,
numberOfZCellsPerBlock ) );
sforest.calculateProcessDistribution_Default( uint_c( MPIManager::instance()->numProcesses() ), memoryLimit, "hilbert", 10, false, metisConfig );
if( !MPIManager::instance()->rankValid() )
MPIManager::instance()->useWorldComm();
// create StructuredBlockForest (encapsulates a newly created BlockForest)
auto bf = std::make_shared< BlockForest >( uint_c( MPIManager::instance()->rank() ), sforest, keepGlobalBlockInformation );

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auto sbf = std::make_shared< StructuredBlockForest >( bf, numberOfXCellsPerBlock, numberOfYCellsPerBlock, numberOfZCellsPerBlock );

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sbf->createCellBoundingBoxes();
return sbf;
}
//**********************************************************************************************************************
/*!
* \brief Function for creating a structured block forest that represents a uniform block grid.
*
* Uniform block grid: Cartesian domain decomposition into blocks of cells, each block has the same size and contains
* the same number of cells.
* The number of active MPI processes is used in order to determine the process distribution = in order to perform the
* initial, static load balancing. Each block is assumed to generate the same amount of work and to require the same
* amount of memory.
*
* \param numberOfXBlocks Number of blocks in x direction
* \param numberOfYBlocks Number of blocks in y direction
* \param numberOfZBlocks Number of blocks in z direction
* \param numberOfXCellsPerBlock Number of cells of each block in x direction
* \param numberOfYCellsPerBlock Number of cells of each block in y direction
* \param numberOfZCellsPerBlock Number of cells of each block in z direction
* \param dx Edge length of each cell (cells are assumed to be cubes)
* \param maxBlocksPerProcess Maximum number of blocks that are allowed to be assigned to one process. If a
* value of '0' is provided, any number of blocks are allowed to be located on one
* process - meaning static load balancing doesn't try to obey any memory limit. ['0' by default]
* \param includeMetis If true (and if available!), METIS is also used during load balancing. [true by default]
* \param forceMetis If true, METIS is always preferred over space filling curves [false by default]
* \param xPeriodic If true, the block structure is periodic in x direction [false by default]
* \param yPeriodic If true, the block structure is periodic in y direction [false by default]
* \param zPeriodic If true, the block structure is periodic in z direction [false by default]
* \param keepGlobalBlockInformation If true, each process keeps information about remote blocks (blocks that reside
* on other processes). This information includes the process rank, the state, and
* the axis-aligned bounding box of any block (local or remote). [false by default]
*/
//**********************************************************************************************************************
shared_ptr< StructuredBlockForest >
createUniformBlockGrid( const uint_t numberOfXBlocks, const uint_t numberOfYBlocks, const uint_t numberOfZBlocks,
const uint_t numberOfXCellsPerBlock, const uint_t numberOfYCellsPerBlock, const uint_t numberOfZCellsPerBlock,
const real_t dx,
const uint_t maxBlocksPerProcess /*= 0*/, const bool includeMetis /*= true*/, const bool forceMetis /*= false*/,
const bool xPeriodic /*= false*/, const bool yPeriodic /*= false*/, const bool zPeriodic /*= false*/,
const bool keepGlobalBlockInformation /*= false*/ ) {
return createUniformBlockGrid( AABB( real_c(0), real_c(0), real_c(0), dx * real_c( numberOfXBlocks * numberOfXCellsPerBlock ),
dx * real_c( numberOfYBlocks * numberOfYCellsPerBlock ),
dx * real_c( numberOfZBlocks * numberOfZCellsPerBlock ) ),
numberOfXBlocks, numberOfYBlocks, numberOfZBlocks,
numberOfXCellsPerBlock, numberOfYCellsPerBlock, numberOfZCellsPerBlock,
maxBlocksPerProcess, includeMetis, forceMetis, xPeriodic, yPeriodic, zPeriodic, keepGlobalBlockInformation );
}
//**********************************************************************************************************************
/*!
* \brief Function for creating a structured block forest that represents a uniform block grid.
*
* Uniform block grid: Cartesian domain decomposition into blocks of cells, each block has the same size and contains
* the same number of cells.
* The entire block structure and its corresponding process distribution are loaded from file.
*
* \param filename A file that stores a block structure and its corresponding process distribution
* \param numberOfXCellsPerBlock Number of cells of each block in x direction
* \param numberOfYCellsPerBlock Number of cells of each block in y direction
* \param numberOfZCellsPerBlock Number of cells of each block in z direction
* \param keepGlobalBlockInformation If true, each process keeps information about remote blocks (blocks that reside
* on other processes). This information includes the process rank, the state, and
* the axis-aligned bounding box of any block (local or remote). [false by default]
*/
//**********************************************************************************************************************
shared_ptr< StructuredBlockForest >
createUniformBlockGrid( const std::string& filename,
const uint_t numberOfXCellsPerBlock, const uint_t numberOfYCellsPerBlock, const uint_t numberOfZCellsPerBlock,
const bool keepGlobalBlockInformation /*= false*/ )
{
if( !MPIManager::instance()->rankValid() )
MPIManager::instance()->useWorldComm();
auto bf = std::make_shared< BlockForest >( uint_c( MPIManager::instance()->rank() ), filename.c_str(), true, keepGlobalBlockInformation );

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if( !bf->storesUniformBlockGrid() )
WALBERLA_ABORT( "The block forest loaded from file \'" << filename << "\' does not contain a uniform block grid!" );
auto sbf = std::make_shared< StructuredBlockForest >( bf, numberOfXCellsPerBlock, numberOfYCellsPerBlock, numberOfZCellsPerBlock );

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sbf->createCellBoundingBoxes();
return sbf;
}
///////////////////////////////////////////
// HELPER FUNCTIONS //
///////////////////////////////////////////
//*******************************************************************************************************************
/*! Tries to distribute a given amount of total cells to a given amount of blocks
*
* It may happen that divisibility of the nr of cells requested prevents a distribution
* in this case the number of cells is chosen bigger than requested
*
*
* \param cells: total number of cells requested
* \param nrOfBlocks: total number of blocks to distribute the cells to
* \param[out] blocks: calculated number of blocks in x/y/z
* \param[out] cellsPerBlock: how many cells to put on each block
it may happen that divisibility of the number of cells requested prevents a distribution
* in this case the number of cells is chosen (slightly) bigger than requested
*
* Example: in: cells = (10,15,16)
* in: blocks = 8
* out: blocks = (2,2,2)
* out: cellsPerBlock = (5,8,8)
* out: newCells = (10,16,16)
*/
//*******************************************************************************************************************
void calculateCellDistribution( const Vector3<uint_t> & cells, uint_t nrOfBlocks,
Vector3<uint_t> & blocksOut, Vector3<uint_t> & cellsPerBlock)
{
std::vector< real_t > weighting;
weighting.push_back( real_c( cells[0]) );
weighting.push_back( real_c( cells[1]) );
weighting.push_back( real_c( cells[2]) );
std::vector<uint_t> blocks = math::getFactors( nrOfBlocks, 3, weighting );
for( uint_t i = 0; i < 3; ++i )
{
if ( uint_c( cells[i] ) % blocks[i] == 0 )
cellsPerBlock[i] = cells[i] / blocks[i];
else // extend the domain if processesCount does not divide the cell count in this direction
cellsPerBlock[i] = ( cells[i] + blocks[i] ) / blocks[i];
}
for( uint_t i = 0; i < 3; ++i )
blocksOut[i] = blocks[i];
}
void uniformWorkloadAndMemoryAssignment( SetupBlockForest& forest ) {
std::vector< SetupBlock* > blocks;
forest.getBlocks( blocks );
for( uint_t i = 0; i != blocks.size(); ++i ) {
blocks[i]->setWorkload( numeric_cast< workload_t >(1) );
blocks[i]->setMemory( numeric_cast< memory_t >(1) );
}
}
memory_t cellWeightedCommunicationCost( const SetupBlock* const a, const SetupBlock* const b,
uint_t xCellsPerBlock, uint_t yCellsPerBlock, uint_t zCellsPerBlock )
{
for ( auto dIter = stencil::D3Q19::beginNoCenter(); dIter != stencil::D3Q19::end(); ++dIter )
{
auto neighborHoodIdxA = getBlockNeighborhoodSectionIndex( *dIter );
for ( uint_t j = 0; j != a->getNeighborhoodSectionSize( neighborHoodIdxA ); ++j )
{
if( a->getNeighbor(neighborHoodIdxA,j) == b )
{
switch ( *dIter )
{
//faces
case stencil::W: return memory_c( yCellsPerBlock * zCellsPerBlock );
case stencil::E: return memory_c( yCellsPerBlock * zCellsPerBlock );
case stencil::N: return memory_c( xCellsPerBlock * zCellsPerBlock );
case stencil::S: return memory_c( xCellsPerBlock * zCellsPerBlock );
case stencil::T: return memory_c( xCellsPerBlock * yCellsPerBlock );
case stencil::B: return memory_c( xCellsPerBlock * yCellsPerBlock );
//edges
case stencil::NW: return memory_c( zCellsPerBlock );
case stencil::NE: return memory_c( zCellsPerBlock );
case stencil::SW: return memory_c( zCellsPerBlock );
case stencil::SE: return memory_c( zCellsPerBlock );
case stencil::TN: return memory_c( xCellsPerBlock );
case stencil::TS: return memory_c( xCellsPerBlock );
case stencil::TW: return memory_c( yCellsPerBlock );
case stencil::TE: return memory_c( yCellsPerBlock );
case stencil::BN: return memory_c( xCellsPerBlock );
case stencil::BS: return memory_c( xCellsPerBlock );
case stencil::BW: return memory_c( yCellsPerBlock );
case stencil::BE: return memory_c( yCellsPerBlock );
default:
WALBERLA_ABORT( "Unknown direction. Should not happen!" )
}
}
}
}
// Return 1 for corners
return numeric_cast< memory_t >(1);
}
memory_t uniformFacesDominantCommunication( const SetupBlock* const a, const SetupBlock* const b ) {
uint_t faces[] = { 4, 10, 12, 13, 15, 21 };
for( uint_t i = 0; i != 6; ++i ) {
for( uint_t j = 0; j != a->getNeighborhoodSectionSize(faces[i]); ++j )
if( a->getNeighbor(faces[i],j) == b )
return numeric_cast< memory_t >(1000);
}
return numeric_cast< memory_t >(1);
}
} // namespace blockforest
} // namespace walberla