OpenFOAM网格分区资料整理

OpenFOAM网格分区资料整理

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Foam::distributionMap

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Foam::mapDistribute

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Foam::ProcessorTopology

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Foam::processorMeshes

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Foam::globalIndex

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Foam::globalIndexAndTransform

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Foam::globalMeshData

Detailed Description
Various mesh related information for a parallel run. Upon construction, constructs all info using parallel communication.

Requires:

all processor patches to have correct ordering.
all processorPatches to have their transforms set.
The shared point and edge addressing calculates addressing for points and edges on coupled patches. In the ‘old’ way a distinction was made between points/edges that are only on two processors and those that are on multiple processors. The problem is that those on multiple processors do not allow any transformations and require a global reduction on the master processor.

The alternative is to have an exchange schedule (through a ‘distributionMap’) which sends all point/edge data (no distinction is made between those on two and those on more than two coupled patches) to the local ‘master’. This master then does any calculation and sends the result back to the ‘slave’ points/edges. This only needs to be done on points on coupled faces. Any transformation is done using a predetermined set of transformations - since transformations have to be space filling only a certain number of transformation is supported.

The exchange needs

a field of data
a distributionMap which does all parallel exchange and transformations This appends remote data to the end of the field.
a set of indices which indicate where to get untransformed data in the field
a set of indices which indicate where to get transformed data in the field
Note:

compared to 17x nTotalFaces, nTotalPoints do not compensate for shared points since this would trigger full connectivity analysis
most calculation is demand driven and uses parallel communication so make sure to invoke on all processors at the same time
old sharedEdge calculation: currently an edge is considered shared if it uses two shared points and is used more than once. This is not correct on processor patches but it only slightly overestimates the number of shared edges. Doing full analysis of how many patches use the edge would be too complicated

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Foam::syncTools

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Foam::Map

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Foam::PstreamBuffers

Buffers for inter-processor communications streams

 PstreamBuffers pBuffers(Pstream::commsTypes::nonBlocking);

 for (label proci = 0; proci < Pstream::nProcs(); proci++)
 {
	 if (proci != Pstream::myProcNo())
	 {
		 someObject vals;

		 UOPstream str(proci, pBuffers);
		 str << vals;
	 }
 }

 pBuffers.finishedSends();   // no-op for blocking

 for (label proci = 0; proci < Pstream::nProcs(); proci++)
 {
	 if (proci != Pstream::myProcNo())
	 {
		 UIPstream str(proci, pBuffers);
		 someObject vals(str);
	 }
 }