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

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 0xfffef0071010
freeing memory at 0xfffef0070bc0
freeing memory at 0xfffef0071300
freeing memory at 0xfffef006f1e0
freeing memory at 0xfffef0070ff0
freeing memory at 0xfffef00712c0
freeing memory at 0xfffef00712a0
freeing memory at 0xfffef0006fa0
freeing memory at 0xfffef00718d0

See also

Ways to use this method:


The source of this document is in ForeignFunctions.m2:1806:0.