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registerFinalizer(ForeignObject,Function) -- register a finalizer for a foreign object

Synopsis

Description

If a foreign pointer object corresponds to memory that was not allocated by the GC garbage collector, then a function to properly deallocate this memory when the Pointer object that stores this pointer is garbage collected should be called. The function should take a single argument, a foreign object, typically of type voidstar, which corresponds to the memory to deallocate.

i1 : malloc = foreignFunction("malloc", voidstar, ulong)

o1 = malloc

o1 : ForeignFunction
i2 : free = foreignFunction("free", void, voidstar)

o2 = free

o2 : ForeignFunction
i3 : finalizer = x -> (print("freeing memory at " | net x); free x)

o3 = finalizer

o3 : FunctionClosure
i4 : for i to 9 do (x := malloc 8; registerFinalizer(x, finalizer))
i5 : collectGarbage()
freeing memory at 0x7bd34406a630
freeing memory at 0x7bd34406a610
freeing memory at 0x7bd344063fc0
freeing memory at 0x7bd344069580
freeing memory at 0x7bd344067050
freeing memory at 0x7bd344063dd0
freeing memory at 0x7bd344063ff0
freeing memory at 0x7bd34405f7f0
freeing memory at 0x7bd344063df0

See also

Ways to use this method: