2015/11/25 3:42 -0800, a...@redhat.com: > On 11/24/2015 05:47 PM, Roger Riggs wrote: >> Memory is an increasingly critical resource, we should be giving >> developers more tools to manage their use of memory. The Weak and >> Soft reference forms of the cleaner make it easier to be aware of >> and respond to increased memory pressure. >> >> ... > > By "memory" here, do you mean native memory for buffers, etc? I'm > guessing so. If so, I'm not sure that it makes sense to think of this > as a cure for flaky finalization. We've got a cure for early > finalization now with keepAlive() (or whatever it gets called) but > late (or never) finalization is as far as I can see unfixable. IMVHO > it makes more sense to encourage developers to get away from lifecycle > maintenance based on reachability.
I could not agree more strongly! > Unfortunately the current design for ByteBuffers does not allow > unmap(), so large mapped buffers may hang around for a long time. > 4724038 says > > "We ... have given this problem a lot of thought ... We have yet to > come up with a way to implement an unmap() method that's safe, > efficient, and plausibly portable across operating systems. We've > explored several other alternatives aside from the two described > above, but all of them were even more problematic. We'd be thrilled > if someone could come up with a workable solution, so we'll leave > this bug open in the hope that it will attract attention from someone > more clever than we are." > > I'm very tempted to take a bite at this, but the above text is rather > forbidding. I think I know how to do it. (Famous last words?) As the author of the above-quoted paragraph, I wish you luck. It's a tough problem. Random musing: I wrote those words in 2005. At this point in time I suspect that an unmap method that works on some operating system but not others might be more acceptable than it would have been back then. - Mark
