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

[Andrew Haley]

On 09/11/2015 07:15 AM, David Holmes wrote:
> On 11/09/2015 12:56 AM, Vitaly Davidovich wrote:
>>>
>>> Sure, if you like, but that's a detail.  We are arguing about what
>>> colour to paint the bike shed.  :)
>>
>>
>> The reason it may be more than just a bikeshed is because if this requires
>> more cleverness in the segfault handler, then it's yet more work to make
>> this happen.  I agree it's an implementation detail, but I don't think it's
>> trivial (unless someone comes along and says that modifying the trap
>> handler to account for this type of scenario is trivial).  One would also
>> need to modify the safepoint code in the VM to allow skipping all the
>> housekeeping it does typically, but I suspect this part is fairly easy.
> 
> Not sure how the safepoint code is supposed to know this particular 
> safepoint is "special".

I guess I don't know what the problem is: when you request a safepoint you
also pass a code saying what you want to happen.

Andrew.