JEP 132: More-prompt finalization

[Tony Printezis]

Kirk,

Consider the case where B becomes garbage in Host 2 but Host 2 is not 
doing much so the next Full GC in Host 2 happens 2 days later. During 
that time A cannot be collected as Host 1 still thinks there's a remote 
reference to A and Host 2 knows that it holds a remote reference from B 
to A but does not know that B is dead.

Tony

On 01/05/2012 11:29 AM, Kirk Pepperdine wrote:
>
>> Host 1: has object A
>> Host 2: has object B that has a remote reference to A
>>
>> Host 1 does not know anything about what's happening in Host 2. The 
>> only thing it has been told is that there's a remote reference to 
>> object A. When Host 2 discovers that B is dead it has to somehow tell 
>> Host 1 that the remote reference to A does not exist any more. This 
>> will allow Host 1 to collect A as long as it's not otherwise 
>> unreachable. If Host 2 crashes, that message will never be sent. Not 
>> sure what happens in that case, I assume hosts have to frequently 
>> refresh the remote references so the ref to A will not be refreshed 
>> and eventually be considered dead?
>
> If host2 dies, I would assume that the socket connection it had opened 
> with host1 would break. But that is an exceptional case. In the 
> functional case, B will dereference A which should pass a single along 
> to the B proxy running in host 1 that A should be dereferenced.  If B 
> is collected in Host2, B proxy should be released and collected in 
> Host1 via normal dereferencing. I don't see a need to call System.gc().
>
> Kirk
>
>