support is included because ROMIO is inherently thread-unsafe.
One possible way to have true asynchronous progress would be to use a
progress thread that wakes up and polls at some frequency when there
are non-blocking IO requests pending. This is pretty icky, though --
it should definitely have an MCA parameter to enable/disable this
functionality, as well as another to control the polling frequency.
This also strengthens the argument that we need a v2 of the io
framework -- one that is not designed to exclusively support ROMIO --
one that does something unimaginably "better" for the parallel MPI-2
IO interface. :-)
This commit was SVN r3786.
ac5f313af8