Editing Tracing garbage collection (section)

== Determinism ==
* Tracing garbage collection is not [[deterministic algorithm|deterministic]] in the timing of object finalization. An object which becomes eligible for garbage collection will usually be cleaned up eventually, but there is no guarantee when (or even if) that will happen. This is an issue for program correctness when objects are tied to non-memory resources, whose release is an externally visible program behavior, such as closing a network connection, releasing a device or closing a file. One garbage collection technique which provides determinism in this regard is [[reference counting]].
* Garbage collection can have a nondeterministic impact on execution time, by potentially introducing pauses into the execution of a program which are not correlated with the algorithm being processed. Under tracing garbage collection, the request to allocate a new object can sometimes return quickly and at other times trigger a lengthy garbage collection cycle. Under reference counting, whereas allocation of objects is usually fast, decrementing a reference is nondeterministic, since a reference may reach zero, triggering recursion to decrement the reference counts of other objects which that object holds.