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

[Andrew Haley]

On 09/08/2015 08:15 PM, Remi Forax wrote:
> On 09/08/2015 03:29 PM, Andrew Haley wrote:
>> On 09/08/2015 02:05 PM, Andrew Haley wrote:
>>> I don't think you'd actually need to unmap anything until a safepoint.
>>> I don't think that the speed of unmapping is critical as long as it
>>> happens "soon".
>>
>> Although given the desire to do
>>
>>   buffer.unmap();
>>   file.delete();
>>
>> that belief may be misplaced.  We could just block for a safepoint;
>> we already do that in other cases, and there's no guarantee about how
>> long unmap() would take to execute.
> 
> I think a simple way to solve that is to ask for a safepoint explicitly,
> 
>   buffer.unmap();
>   waitUntilUnmapped();
>   file.delete();

Umm, why?  Java methods usually don't return until they've finished.  I
can't think of any application requirement for asynchronous operation in
this particular case.

Andrew.