This commit fixes several bugs in the registration cache code:
- Fix a programming error in the grdma invalidation function that can
cause an infinite loop if more than 100 registrations are
associated with a munmapped region. This happens because the
mca_rcache_base_vma_find_all function returns the same 100
registrations on each call. This has been fixed by adding an
iterate function to the vma tree interface.
- Always obtain the vma lock when needed. This is required because
there may be other threads in the system even if
opal_using_threads() is false. Additionally, since it is safe to do
so (the vma lock is recursive) the vma interface has been made
thread safe.
- Avoid calling free() while holding a lock. This avoids race
conditions with locks held outside the Open MPI code.
Fixesopen-mpi/ompi#1654.
Signed-off-by: Nathan Hjelm <hjelmn@lanl.gov>