On 08/08/14 09:01, Jaroslav Tulach wrote: > Given the fact that WeakReference & co. has been introduced in JDK > 1.2 and that version was released at the end of 1998, I bet it was > just a communication problem, as Andrew must have been talking about > something else than WeakReference + ReferenceQueue behavior.
You don't have to believe me, read this: http://thevirtualmachinist.blogspot.co.uk/2011/07/subtle-issue-of-reachability.html http://thevirtualmachinist.blogspot.co.uk/2011/07/reachability-follow-up.html The problem is not to do with WeakReferences or ReferenceQueues, but with the notion of reachability in the VM. The language which permits this behaviour is: "Optimizing transformations of a program can be designed that reduce the number of objects that are reachable to be less than those which would naively be considered reachable. For example, a Java compiler or code generator may choose to set a variable or parameter that will no longer be used to null to cause the storage for such an object to be potentially reclaimable sooner. "Another example of this occurs if the values in an object's fields are stored in registers. The program may then access the registers instead of the object, and never access the object again. This would imply that the object is garbage." Andrew.
