- can be used, for example, to track global states:
// Encode as 0:empty, 1:uniform, 2:nonuniform, 3:mixed
PackedList<2> uniformity(fields.size());
forAll(fields, i)
{
uniformity.set(i, fields[i].whichUniformity());
}
reduce
(
uniformity.data(),
uniformity.size_data(),
bitOrOp<unsigned>()
);
- MPI_THREAD_MULTIPLE is usually undesirable for performance reasons,
but in some cases may be necessary if a linked library expects it.
Provide a '-mpi-threads' option to explicitly request it.
ENH: consolidate some looping logic within argList
- similar to UPstream::parRun(), the setter returns the previous value.
The accessors are prefixed with 'comm':
Eg, commGlobal(), commWarn(), commWorld(), commSelf().
This distinguishes them from any existing variables (eg, worldComm)
and arguably more similar to MPI_COMM_WORLD etc...
If demand-driven communicators are added in the future, the function
call syntax can help encapsulate that.
Previously:
const label oldWarnComm = UPstream::warnComm;
const label oldWorldComm = UPstream::worldComm;
UPstream::warnComm = myComm;
UPstream::worldComm = myComm;
...
UPstream::warnComm = oldWarnComm;
UPstream::worldComm = oldWorldComm;
Now:
const label oldWarnComm = UPstream::commWarn(myComm);
const label oldWorldComm = UPstream::commWorld(myComm);
...
UPstream::commWarn(oldWarnComm);
UPstream::commWorld(oldWorldComm);
STYLE: check (warnComm >= 0) instead of (warnComm != -1)
- UPstream::globalComm constant always refers to MPI_COMM_WORLD but
UPstream::worldComm could be MPI_COMM_WORLD (single world)
or a dedicated local communicator (for multi-world).
- provide a Pstream wrapped version of MPI_COMM_SELF,
references as UPstream::selfComm
- UPstream::isUserComm(label)
test for additional user-defined communicators
