- "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
- previously had an additional stack for freedRequests_,
which were used to 'remember' locations into the list of
outstandingRequests_ that were handled by 'waitRequest()'.
This was principally done for sanity checks on shutdown,
but we now just test for any outstanding requests that
are *not* MPI_REQUEST_NULL instead (much simpler).
The framework with freedRequests_ also had a provision to 'recycle'
them by popping from that stack, but this is rather fragile since it
would only triggered by some collectives
(MPI_Iallreduce, MPI_Ialltoall, MPI_Igather, MPI_Iscatter)
with no guarantee that these will all be properly removed again.
There was also no pruning of extraneous indices.
ENH: consolidate internal reset/push of requests
- replace duplicate code with inline functions
reset_request(), push_request()
ENH: null out trailing requests
- extra safety (paranoia) for the UPstream::Request versions
of finishedRequests(), waitAnyRequest()
CONFIG: document nPollProcInterfaces in etc/controlDict
- still experimental, but at least make the keyword known
- separate broadcast times from reduce/gather/scatter time
- separate wait times from all-to-all time
- support invocation counts, split off requests time/count
from others to avoid flooding the counts
- support 'detail' switch to increase the output information.
Format may change in the future
- 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::Request wrapping class provides an opaque wrapper for
vendor MPI_Request values, independent of global lists.
ENH: support for MPI barrier (blocking or non-blocking)
ENH: support for MPI sync-send variants
STYLE: deprecate waitRequests() without a position parameter
- in many cases this can indicate a problem in the program logic since
normally the startOfRequests should be tracked locally.
- the internal data are contiguous so can broadcast size and internals
directly without an intermediate stream.
ENH: split out broadcast time for profilingPstream information
STYLE: minor Pstream cleanup
- UPstream::commsType_ from protected to private, since it already has
inlined noexcept getters/setters that should be used.
- don't pass unused/unneed tag into low-level MPI reduction templates.
Document where tags are not needed
- had Pstream::broadcast instead of UPstream::broadcast in internals
- refactor as an MPI-independent base class.
Add bufferIPC{send,recv} private methods for construct/destruct.
Eliminates code duplication from two constructor forms and reduces
additional constructor definitions in dummy library.
- add PstreamBuffers access methods, refactor common finish sends
code, tweak member packing
ENH: resize_nocopy for processorLduInterface buffers
- content is immediately overwritten
STYLE: cull unneeded includes in processorFa*
- handled by processorLduInterface
