- "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
- can use UList signature since the routines do not resize the list
or attempt to broadcast it: useful for SubList handling.
ENH: add IPstream/OPstream send/recv static methods
- 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
