Suggested fix for JDK-4724038 (Add unmap method to MappedByteBuffer)

[Andrew Haley]

On 09/10/2015 03:35 PM, Vitaly Davidovich wrote:

> Well, you'd probably want something other than NPE here -- perhaps a
> new dedicated exception to signal this condition. 

Sure, if you like, but that's a detail.  We are arguing about what
colour to paint the bike shed.  :)

> And this means the segfault handling now needs to know about this
> type of situation as well, rather than just NPEs.

Maybe, but perhaps not.  The access to the guard page might just
trigger the usual segfault path, which (given an oop map) looks just
like a null pointer exception.

Andrew.