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Subject: [OMPI devel] RFC: opal_value_array
From: Ralph Castain (rhc_at_[hidden])
Date: 2010-01-15 19:47:35

Hi folks

I don't think this actually impacts much other than ORTE, and mostly my efforts. But since it involves a change to an opal class function, I thought I would at least send out a "heads up".

WHAT: modify opal_value_array class to allow developers to identify an "invalid" value that will be used to pre-load the array so subsequent calls can tell if valid values were entered into an array position

WHY: thread safety, for one. Currently, there is no way for one thread to determine that another thread has actually entered a value in an array position

IMPACT: (a) will modify the opal_value_array_init function to add a parameter that points to the "invalid" value for that array (NULL => no invalid value provided); (b) will modify the internal function that grows an array to pre-load it with that value if it was provided

WHERE: almost exclusively in a handful of places in ORTE. Only exception are a few calls to carto graph distance function, one of which is in the sm btl.

WHEN: Jan 22, 2010

Let me know if you care about this - it is pretty trivial, but required for thread safety.