Monday, February 23, 2009
Bug 4724038
Today I stumbled upon the Java bug 4724038 (although Sun considers it an RFE).
The bug is related to the fact that Java memory mapping does not provide an unmap() method, due to security/efficiency issues.
It is 6 years old and it is currently ranked third in the top 25 RFEs list.
Looking at the comments its page, this bug has upset many developers along the years.
The final words in the bug evaluation section are really disarming:
[..] We at Sun have given this problem a lot of thought, both during the original development of NIO and in the time since. 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 going to try some of the proposed workarounds to the problem, and the I’ll post a comment on which one as worked best for me.