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Subject: [OMPI devel] opal_value_array
From: Ralph Castain (rhc_at_[hidden])
Date: 2009-02-24 21:48:03


I recently spent several days attempting to track down a bug in the
trunk, finally finding that the root cause was linked to a rather
strange behavior of the opal_value_array class.

If you call opal_value_array_get_item and request an index that is
beyond that of the current size of the array, this function will
automatically increase the size of the value array, and return
whatever garbage is sitting in the expanded memory location. There is
no warning this has happened - no error code is returned, the memory
is not zero'd, etc. What you get back may be indistinguishable from a
"real", albeit nonsensical, value.

Can someone explain why this behavior was considered desirable? It was
clearly a designed response - I simply cannot see -why- we would want
this behavior. If you request a value outside the bound of the array,
what purpose is served by returning garbage as if it were "valid"?

Ralph