Well, at this point the only thing that's entirely clear is that none
of the ideas I had work. I think we are going to be forced to pursue
Noah's idea of doing an end-to-end retry. Somebody else will need to
take point on that; I lack a Windows environment and have already done
a lot more blind patch-pushing than I like in this effort.
I'll revert the debugging code I added to win32_shmem.c, unless
someone sees a reason to leave it there awhile longer.
regards, tom lane