GC

Reference counting and garbage collector operations. More...

Functions
nix_err	nix_gc_incref (nix_c_context *context, const void *object)
	Increase the GC refcount. More...
nix_err	nix_gc_decref (nix_c_context *context, const void *object)
	Decrease the GC refcount. More...
void	nix_gc_now ()
	Trigger the garbage collector manually. More...
void	nix_gc_register_finalizer (void *obj, void *cd, void(*finalizer)(void *obj, void *cd))
	Register a callback that gets called when the object is garbage collected. More...

Detailed Description

Reference counting and garbage collector operations.

Nix's evaluator uses a garbage collector. To ease C interop, we implement a reference counting scheme, where objects will be deallocated when there are no references from the Nix side, and the reference count kept by the C API reaches 0.

Functions returning a garbage-collected object will automatically increase the refcount for you. You should make sure to call nix_gc_decref when you're done.

Function Documentation

nix_gc_decref()

nix_err nix_gc_decref	(	nix_c_context *	context,
		const void *	object
	)

Decrease the GC refcount.

Parameters

[out]	context	Optional, stores error information
[in]	object	The object to stop referencing

nix_gc_incref()

nix_err nix_gc_incref	(	nix_c_context *	context,
		const void *	object
	)

Increase the GC refcount.

The nix C api keeps alive objects by refcounting. When you're done with a refcounted pointer, call nix_gc_decref.

Parameters

[out]	context	Optional, stores error information
[in]	object	The object to keep alive

nix_gc_now()

void nix_gc_now

(

)

Trigger the garbage collector manually.

You should not need to do this, but it can be useful for debugging.

nix_gc_register_finalizer()

void nix_gc_register_finalizer	(	void *	obj,
		void *	cd,
		void(*)(void *obj, void *cd)	finalizer
	)

Register a callback that gets called when the object is garbage collected.

Note

objects can only have a single finalizer. This function overwrites silently.

Parameters

[in]	obj	the object to watch
[in]	cd	the data to pass to the finalizer
[in]	finalizer	the callback function, called with obj and cd