On Dec 26, 2006, at 8:30 PM, Xiao-Feng Li wrote:
On 12/27/06, Geir Magnusson Jr. <[EMAIL PROTECTED]> wrote:
On Dec 26, 2006, at 10:53 AM, Weldon Washburn wrote:
>
> 5)
> How are real java apps designed? What do they really use finalizer
> for?
I don't believe that people use them anymore. When I was writing
real things in Java, I never used them - I made sure that resource
management and such was deliberate, and not dependent upon when and
if (and even where - it can run in any thread, right?) the finalizer
ran.
Yes, it's encouraged not to use finalizer at all in Java app, or
discouraged to use it. The idea to put resource management in
finalizer then give up the control is problematic. At the same time,
the finalization subsystem takes all the responsility of resource
management and works to avoid all the app design issues is unfair. It
is ultimately impossible unless the finalization system deeply
involves with the app activity (such as what Pavel Afremov said to
identify the "good" app threads), but then the finalization subsystem
knows too much about the app internals, and virually part of the app
in semantics. If that's the only way to make the finalization
subsystem really work, I would choose to manage the resources in app
directly, not to use finalizers at the beginning.
Right - the finalizer can't actually know.
If in very rare cases some apps indeed have undesirable finalizer
behavior, we can take two actions at the same time with priority
order: 1. to tell the programmer that his design has some unexpected
finalizers and suggest to change the design, 2. if the app is
important, we can afford some time to study its behavior and think of
some solution in our VM.
Why can't we simply mimic the rational behavior of the RI and other
production VMs and leave it at that?
geir
