Specific to the VOF-to-lagrangian FO is to generate particles
which potentially do not relate to the mesh. So here they
are preserved instead of trying to locate them on the
reconstructed mesh. Note: this has the same effect
of actually copying the file...
- simplify procAddressing read/write
- avoid accessing points in faMeshReconstructor.
Can rely on the patch meshPoints (labelList), which does not need
access to a pointField
- report number of points on decomposed mesh.
Can be useful additional information.
Additional statistics for finite area decomposition
- provide bundled reconstructAllFields for various reconstructors
- remove reconstructPar checks for very old face addressing
(from foam2.0 - ie, older than OpenFOAM itself)
- bundle all reading into fieldsDistributor tools,
where it can be reused by various utilities as required.
- combine decomposition fields as respective fieldsCache
which eliminates most of the clutter from decomposePar
and similfies reuse in the future.
STYLE: remove old wordHashSet selection (deprecated in 2018)
BUG: incorrect face flip handling for faMeshReconstructor
- a latent bug which is not yet triggered since the faMesh faces are
currently only definable on boundary faces (which never flip)
- bundles frequently used 'gather/scatter' patterns more consistently.
- combineAllGather -> combineGather + broadcast
- listCombineAllGather -> listCombineGather + broadcast
- mapCombineAllGather -> mapCombineGather + broadcast
- allGatherList -> gatherList + scatterList
- reduce -> gather + broadcast (ie, allreduce)
- The allGatherList currently wraps gatherList/scatterList, but may be
replaced with a different algorithm in the future.
STYLE: PstreamCombineReduceOps.H is mostly unneeded now
STYLE: LduInterfaceFieldPtrsList as alias instead of a class
STYLE: define patch lists typedefs when defining the base patch
- eg, polyPatchList typedef within polyPatch.H
INT: relocate GeometricField::Boundary -> GeometricBoundaryField
- was internal to GeometricField but moving it outside simplifies
forward declarations etc. Code adapted from openfoam.org
- gather/scatter types of operations can avoid AllToAll communication
and use simple MPI gather (or scatter) to establish the receive sizes.
New methods: finishedGathers() / finishedScatters()
- PstreamBuffers nProcs() and allProcs() methods to recover the rank
information consistent with the communicator used for construction
- allowClearRecv() methods for more control over buffer reuse
For example,
pBufs.allowClearRecv(false);
forAll(particles, particlei)
{
pBufs.clear();
fill...
read via IPstream(..., pBufs);
}
This preserves the receive buffers memory allocation between calls.
- finishedNeighbourSends() method as compact wrapper for
finishedSends() when send/recv ranks are identically
(eg, neighbours)
- hasSendData()/hasRecvData() methods for PstreamBuffers.
Can be useful for some situations to skip reading entirely.
For example,
pBufs.finishedNeighbourSends(neighProcs);
if (!returnReduce(pBufs.hasRecvData(), orOp<bool>()))
{
// Nothing to do
continue;
}
...
On an individual basis:
for (const int proci : pBufs.allProcs())
{
if (pBufs.hasRecvData(proci))
{
...
}
}
Also conceivable to do the following instead (nonBlocking only):
if (!returnReduce(pBufs.hasSendData(), orOp<bool>()))
{
// Nothing to do
pBufs.clear();
continue;
}
pBufs.finishedNeighbourSends(neighProcs);
...
- the patch remapping in faFieldDecomposer calls weights
internalField() which can trigger parallel communication on the
complete mesh for some processors only (ie, blocks).
Force a priori creation of weights instead.
- ensure that the complete mesh (reconstruction helper)
is serial when adding patches.
- when creating a finite-area mesh in parallel, need to determine
the equivalent ProcAddressing for the faMesh.
In the faceProcAddressing the collected and sorted order was being
scattered directly back to the individual processors instead of only
the sections relevant to each particular processor.
This caused the observed jumbled order for reconstructed fields.
- A bare-bones reconstructor for finiteArea meshes when processor
meshes are available (in parallel) but an equivalent serial faMesh
is needed for reconstruction or decomposition.
In these situations, a serial version of the faMesh is needed,
but preferably without reconstructing the entire volume mesh.
It uses the finiteVolume faceProcAddressing in addition to
the geometric information available from the underlying polyMesh.
The resulting equivalent faMesh can be used for basic operations,
but caution should be exercised before attempting large operations.
- simplifies usage.
Support syncPar check on names() to detect inconsistencies.
- simplify readFields, ReadFields and other routines by using these
new methods.
- generalize some of the library extensions (.so vs .dylib).
Provide as wmake 'sysFunctions'
- added note about unsupported/incomplete system support
- centralize detection of ThirdParty packages into wmake/ subdirectory
by providing a series of scripts in the spirit of GNU autoconfig.
For example,
have_boost, have_readline, have_scotch, ...
Each of the `have_<package>` scripts will generally provide the
following type of functions:
have_<package> # detection
no_<package> # reset
echo_<package> # echoing
and the following type of variables:
HAVE_<package> # unset or 'true'
<package>_ARCH_PATH # root for <package>
<package>_INC_DIR # include directory for <package>
<package>_LIB_DIR # library directory for <package>
This simplifies the calling scripts:
if have_metis
then
wmake metisDecomp
fi
As well as reducing clutter in the corresponding Make/options:
EXE_INC = \
-I$(METIS_INC_DIR) \
-I../decompositionMethods/lnInclude
LIB_LIBS = \
-L$(METIS_LIB_DIR) -lmetis
Any additional modifications (platform-specific or for an external build
system) can now be made centrally.
- The central InfoSwitch "writeLagrangianPositions" allows writing an
additional Lagrangian "positions" file, but these were not being
written by reconstructPar. These are now also written in reconstructPar
if the central writeLagrangianPositions InfoSwitch is enabled.
NOTES
- "positions" are reconstructed from the processors "coordinates" file
- decomposePar will not attempt to create or redistribute any
"positions" files
Original commit message:
------------------------
Parallel IO: New collated file format
When an OpenFOAM simulation runs in parallel, the data for decomposed fields and
mesh(es) has historically been stored in multiple files within separate
directories for each processor. Processor directories are named 'processorN',
where N is the processor number.
This commit introduces an alternative "collated" file format where the data for
each decomposed field (and mesh) is collated into a single file, which is
written and read on the master processor. The files are stored in a single
directory named 'processors'.
The new format produces significantly fewer files - one per field, instead of N
per field. For large parallel cases, this avoids the restriction on the number
of open files imposed by the operating system limits.
The file writing can be threaded allowing the simulation to continue running
while the data is being written to file. NFS (Network File System) is not
needed when using the the collated format and additionally, there is an option
to run without NFS with the original uncollated approach, known as
"masterUncollated".
The controls for the file handling are in the OptimisationSwitches of
etc/controlDict:
OptimisationSwitches
{
...
//- Parallel IO file handler
// uncollated (default), collated or masterUncollated
fileHandler uncollated;
//- collated: thread buffer size for queued file writes.
// If set to 0 or not sufficient for the file size threading is not used.
// Default: 2e9
maxThreadFileBufferSize 2e9;
//- masterUncollated: non-blocking buffer size.
// If the file exceeds this buffer size scheduled transfer is used.
// Default: 2e9
maxMasterFileBufferSize 2e9;
}
When using the collated file handling, memory is allocated for the data in the
thread. maxThreadFileBufferSize sets the maximum size of memory in bytes that
is allocated. If the data exceeds this size, the write does not use threading.
When using the masterUncollated file handling, non-blocking MPI communication
requires a sufficiently large memory buffer on the master node.
maxMasterFileBufferSize sets the maximum size in bytes of the buffer. If the
data exceeds this size, the system uses scheduled communication.
The installation defaults for the fileHandler choice, maxThreadFileBufferSize
and maxMasterFileBufferSize (set in etc/controlDict) can be over-ridden within
the case controlDict file, like other parameters. Additionally the fileHandler
can be set by:
- the "-fileHandler" command line argument;
- a FOAM_FILEHANDLER environment variable.
A foamFormatConvert utility allows users to convert files between the collated
and uncollated formats, e.g.
mpirun -np 2 foamFormatConvert -parallel -fileHandler uncollated
An example case demonstrating the file handling methods is provided in:
$FOAM_TUTORIALS/IO/fileHandling
The work was undertaken by Mattijs Janssens, in collaboration with Henry Weller.
terms of the local barycentric coordinates of the current tetrahedron,
rather than the global coordinate system.
Barycentric tracking works on any mesh, irrespective of mesh quality.
Particles do not get "lost", and tracking does not require ad-hoc
"corrections" or "rescues" to function robustly, because the calculation
of particle-face intersections is unambiguous and reproducible, even at
small angles of incidence.
Each particle position is defined by topology (i.e. the decomposed tet
cell it is in) and geometry (i.e. where it is in the cell). No search
operations are needed on restart or reconstruct, unlike when particle
positions are stored in the global coordinate system.
The particle positions file now contains particles' local coordinates
and topology, rather than the global coordinates and cell. This change
to the output format is not backwards compatible. Existing cases with
Lagrangian data will not restart, but they will still run from time
zero without any modification. This change was necessary in order to
guarantee that the loaded particle is valid, and therefore
fundamentally prevent "loss" and "search-failure" type bugs (e.g.,
2517, 2442, 2286, 1836, 1461, 1341, 1097).
The tracking functions have also been converted to function in terms
of displacement, rather than end position. This helps remove floating
point error issues, particularly towards the end of a tracking step.
Wall bounded streamlines have been removed. The implementation proved
incompatible with the new tracking algorithm. ParaView has a surface
LIC plugin which provides equivalent, or better, functionality.
Additionally, bug report <https://bugs.openfoam.org/view.php?id=2517>
is resolved by this change.
These new names are more consistent and logical because:
primitiveField():
primitiveFieldRef():
Provides low-level access to the Field<Type> (primitive field)
without dimension or mesh-consistency checking. This should only be
used in the low-level functions where dimensional consistency is
ensured by careful programming and computational efficiency is
paramount.
internalField():
internalFieldRef():
Provides access to the DimensionedField<Type, GeoMesh> of values on
the internal mesh-type for which the GeometricField is defined and
supports dimension and checking and mesh-consistency checking.
The deprecated non-const tmp functionality is now on the compiler switch
NON_CONST_TMP which can be enabled by adding -DNON_CONST_TMP to EXE_INC
in the Make/options file. However, it is recommended to upgrade all
code to the new safer tmp by using the '.ref()' member function rather
than the non-const '()' dereference operator when non-const access to
the temporary object is required.
Please report any problems on Mantis.
Henry G. Weller
CFD Direct.
Moved file path handling to regIOobject and made it type specific so
now every object can have its own rules. Examples:
- faceZones are now processor local (and don't search up anymore)
- timeStampMaster is now no longer hardcoded inside IOdictionary
(e.g. uniformDimensionedFields support it as well)
- the distributedTriSurfaceMesh is properly processor-local; no need
for fileModificationChecking manipulation.
