finalizers

Likewise, finalizers are normally processed as a background task, so their cost is usually amortized across the system's idle time.

Review your finalizers carefully to ensure that even if they do not run , a critical operating system resource is not leaked .

The finalizers are called on objects that are no longer live during the same garbage collection pass .

If you see objects queued for finalization in the verbose GC logs, try to rewrite the application to eliminate the use of finalizers.

Don't rely on finalizers as the primary means of releasing resources.

There are a number of reasons, foremost of which is that finalizers are very tricky to write correctly (and very easy to write incorrectly).

Finalizers can cause a vulnerability in Java code when used to create objects.

Finalizers have a significant performance cost, and they are not guaranteed to run in a predictable amount of time (or even at all).

Methods with parameters are not class finalizers (in fact, a rule should be written to report these as invalid).

Notice that the objects that require finalizers stay in memory for extra cycles .

Instead, the GC places each object that is ready for finalization in a queue and spawns yet another thread to execute all the finalizers.

Finalizers are not executed by the same thread that collects garbage.

at this time , it cannot collect the inaccessible objects that do have finalizers.

For other objects, finalizers are generally best avoided.

Analyze the use of finalizers, including the number of finalizers executed.

The jmap tool is useful in diagnosing excessive use of finalizers, which can result in an OutOfMemoryError.

Whenever you can, avoid finalizers because of the additional performance overhead that is involved in tracking object lifetime.

Still, there are times when you need to use finalizers, and there are a number of errors you can make when doing so.