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ForeignFunctions :: registerFinalizer(ForeignObject,Function)

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 0x7ffcf804f8a0
freeing memory at 0x7ffcf8048a70
freeing memory at 0x7ffcf8048a50
freeing memory at 0x7ffcf804f8c0
freeing memory at 0x7ffcf804f650
freeing memory at 0x7ffcf804f670
freeing memory at 0x7ffcf804f610
freeing memory at 0x7ffcf804fea0
freeing memory at 0x7ffcf804f630
freeing memory at 0x7ffcf804ff60

Ways to use this method: