- the maxCommsSize variable is used to 'chunk' large data transfers
(eg, with PstreamBuffers) into a multi-pass send/recv sequence.
The send/recv windows for chunk-wise transfers:
iter data window
---- -----------
0 [0, 1*chunk]
1 [1*chunk, 2*chunk]
2 [2*chunk, 3*chunk]
...
Since we mostly send/recv in bytes, the current internal limit
for MPI counts (INT_MAX) can be hit rather quickly.
The chunking limit should thus also be INT_MAX, but since it is
rather tedious to specify such large numbers, can instead use
maxCommsSize = -1
to specify (INT_MAX-1) as the limit.
The default value of maxCommsSize = 0 (ie, no chunking).
Note
~~~~
In previous versions, the number of chunks was determined by the
sender sizes. This required an additional MPI_Allreduce to establish
an overall consistent number of chunks to walk. This additional
overhead each time meant that maxCommsSize was rarely actually
enabled.
We can, however, instead rely on the send/recv buffers having been
consistently sized and simply walk through the local send/recvs until
no further chunks need to be exchanged. As an additional enhancement,
the message tags are connected to chunking iteration, which allows
the setup of all send/recvs without an intermediate Allwait.
ENH: extend UPstream::probeMessage to use int64 instead of int for sizes
- the timeSelector is often used to select single or multiple times
(eg, for post-processing). However, there are a few applications
where only a *single* time should be selected and set.
These are now covered by this type of use:
timeSelector::addOptions_singleTime(); // Single-time options
...
// Allow override of time from specified time options, or no-op
timeSelector::setTimeIfPresent(runTime, args);
In some cases, if can be desirable to force starting from the
initial Time=0 when no time options have been specified:
// Set time from specified time options, or force start from Time=0
timeSelector::setTimeIfPresent(runTime, args, true);
These changes make a number of includes redundant:
* addTimeOptions.H
* checkConstantOption.H
* checkTimeOption.H
* checkTimeOptions.H
* checkTimeOptionsNoConstant.H
ENH: add time handling to setFields, setAlphaField (#3143)
Co-authored-by: Johan Roenby <>
STYLE: replace instant("constant") with instant(0, "constant")
- avoids relying on atof parse behaviour returning zero
- for example,
string buffer = ...;
SubStrings<string> split;
{
auto colon = buffer.find(':');
if (colon != std::string::npos)
{
split = stringOps::splitSpace(buffer, colon+1);
}
}
Not really possible with a substr() since that would create a new
temporary which then disappears. Similarly awkward to split and
then scan for the ':' to decide how many to discard.
ENH: add pop_front() and pop_back() methods to SubStrings
- the content is trivial enough (a pair of iterators) and the total
number of elements is usually reasonable short so that removal of
elements is inexpensive
For example,
string buffer = ...;
auto split = stringOps::splitSpace(buffer);
if (!split.empty() && split[0].str() == "face")
{
split.pop_front();
}
- ensures more accurate values for message sizes than using
MPI Get_count(), which trucates at INT_MAX
- add more/better error messages when trying to receive messages
that exceed INT_MAX or the char buffer lengths
- "buffered" corresponds to MPI_Bsend (buffered send),
whereas the old name "blocking" is misleading since the
regular MPI_Send also blocks until completion
(ie, buffer can be reused).
ENH: IPstream::read() returns std::streamsize instead of label (#3152)
- previously returned a 'label' but std::streamsize is consistent with
the input parameter and will help with later adjustments.
- use <label> instead of <int> for internal accounting of the message
size, for consistency with the underyling List<char> buffers used.
- improve handling for corner case of IPstream receive with
non-blocking, although this combination is not used anywhere
- robuster and more reliable determination of inserted objects
(previous code could produce false positives).
Now also determine the number of inserted objects within the
constructor (instead of simply storing a bool). This allows reuse
in the address calculations to reduce overheads there.
BUG: dodgy short-circuit logic for insertedObjectLabels()
- as a quick short-circuit it previously created as demand-driven
pointer with a zero elements. However, this meant that if this code
was called first (before any other addressing), subsequent calls to
the addressing would fail.
BUG: bad logic and lookup for faAreaMapper (#3147)
- was using labelHashSet but returning a bool and set using the
addressing using the unfiltered objects!
This is a latent bug since interpolated/inserted faces not
currently supported anyhow.
ENH: use std::unique_ptr for demand-driven data
- manual revert for 44d0fbd594.
Unless required for post-processing the "value" entry should not
written if it is not mandatory for reading.
This is especially crucial with an 'empty' patch field where the
field (size 0) has a different size from the patch.
- the changes made align fvsPatchField behaviour with fvPatchField
- return autoPtr<token::compound> instead of the derived type,
otherwise cannot easily construct a token from it
ENH: additional typed version of refCompoundToken()
- symmetric with typed version of transferCompoundToken()
and isCompound()
- add ITstream::findCompound<Type>() method.
Useful for searching within token streams
- previously automatically skipped the first communicator (which was
assumed to be MPI_COMM_WORLD), but now simply rely on the
internal pendingMPIFree_ to track which communicators have actually
been allocated.
- UPstream::Communicator is similar to UPstream::Request to
wrap/unwrap MPI_Comm. Provides a 'lookup' method to transcribe
the internal OpenFOAM communicator tracking to the opaque wrapped
version.
- provide an 'openfoam_mpi.H' interfacing file, which includes
the <mpi.h> as well as casting routines.
Example (caution: ugly!)
MPI_Comm myComm =
PstreamUtils::Cast::to_mpi
(
UPstream::Communicator::lookup(UPstream::worldComm)
);
- replace point-to-point transmission of the argList args/options with
a broadcast. This is sufficient for most cases (without distributed
roots).
For "normal" cases (non-distributed roots) this will replace the
nProcs-1 messages with a single broadcast.
- for cases with distributed roots, distinguish between a single,
identical root and different roots. An identical root can also be
subsequently handled with a broadcast. Different roots will still
require individual point-to-point communication.
For cases with distributed roots, it will add the overhead of an
additional broadcast.
- adds consistency with regular point-to-point parallel streams.
ENH: add ITstream::tokens() methods
- useful, for example, to disambiguate constructing tokenList from
a ITstream.
ITstream& is = otherDict.lookup("original");
tokenList deepCopy(is); // Error: from Istream or tokenList??
tokenList deepCopy(is.tokens()); // OK: from tokenList
- The internal storage location of finite-area changes from being
piggybacked on the polyMesh registry to a having its own dedicated
registry:
* allows a clearer separation of field types without name clashes.
* prerequisite for supporting multiple finite-area regions (future)
Old Locations:
```
0/Us
constant/faMesh
system/faMeshDefinition
system/faSchemes
system/faSolution
```
New Locations:
```
0/finite-area/Us
constant/finite-area/faMesh
system/finite-area/faMeshDefinition (or system/faMeshDefinition)
system/finite-area/faSchemes
system/finite-area/faSolution
```
NOTES:
The new locations represent a hard change (breaking change) that
is normally to be avoided, but seamless compatibility handling
within the code was found to be unworkable.
The `foamUpgradeFiniteArea` script provides assistance with migration.
As a convenience, the system/faMeshDefinition location continues
to be supported (may be deprecated in the future).
- Delete() will perform a 'checkOut()' which does the following:
* remove the object from the registry
* delete the pointer (if owned by the registry)
- Release() does the following:
* transfer ownership of the pointer (if owned by the registry)
- Store() does the following:
* transfer ownership of the pointer to the registry
ENH: use UPtrList of sorted objects for MeshObject updates
- few allocations and lower overhead than using a HashTable,
ensures the same walk order over the objects (in parallel)
STYLE: adjust meshObject debug statements
STYLE: update code style for phi modification (engine motion)
ENH: pass isMeshUpdate param in fvMesh/polyMesh clearOut() methods
- top-level use of isMeshUpdate parameter to clearOut and
clearAddressing was being inadvertently filtered out
- after the modification of d578d48a4f, the parent was now actually
searched. However, should be returning "constant" and not trigger a
FatalError if the file/directory is not found.
- findStrings, findMatchingStrings now mostly covered by matching
intrinsics in wordRe and wordRes.
Add static wordRes match() and matching() variants
COMP: remove stringListOps include from objectRegistry.H
- was already noted for removal (NOV-2018)
- NewIFstream would read complete remote file to decide if
was collated.
- This limits files to 31bit size
- Instead now have master-only opening of file.
- Still has problem with refinement history/cellLevel etc.
