On 14/09/2015 22:36, Phil Clayton wrote:
I am trying to create an SML binding to a C function that returns an
array that the caller must free. Usually, there is a free function that
takes just the array (as a pointer) which can be attached as a finalizer
with CInterface.setFinal. I have encountered a case [1] where the
caller must also pass the size of the array, returned when the array is
created, to the free function.
Phil,
I wonder if this is a case for the use of a weak reference (
http://www.polyml.org/documentation/Reference/Weak.html ) ? Have a look
at this link and see whether it would work for you.
Essentially, what weak references do is allow you to run finalisers in
"ML space". CInterface.setFinal sets up a C function to be run as a
finaliser and the GC runs these immediately when it detects an
unreferenced "vol". It can't run an ML function at that point because
the ML heap is still being collected. Changes to weak references are
notified at some point after ML is resumed after the GC.
If you've got any questions please ask. I'd also be interested to know
if it solves your problem.
Regards,
David
_______________________________________________
polyml mailing list
polyml@inf.ed.ac.uk
http://lists.inf.ed.ac.uk/mailman/listinfo/polyml
