It seems to me that an application can usually keep track of whether or not it
called MPI_Cancel. Adding such a feature into MPI seems unneccessary, and
potentially opens a pandora's box of other such features.
Note: the generalized caching proposal would solve such user requests - it
still seems like a good idea, even if it is "yet another if statement".
Lloyd Lewins
Hughes Aircraft Co.,
llewins@msmail4.hac.com