RFR: 8135097: Unmap failure for executable memory on windows

[Coleen Phillimore]

This looks fine to me.
Coleen

On 9/8/15 3:43 PM, Ioi Lam wrote:
> Hi Jiangli,
>
> This looks good to me. We'll need a Reviewer, preferably someone 
> familiar with Win32 APIS.
>
> Thanks
> - Ioi
>
> On 9/4/15 5:04 PM, Jiangli Zhou wrote:
>> Hi,
>>
>> Please review the following bug fix for windows 
>> os::pd_unmap_memory(). The windows os::pd_map_memory() and 
>> os::pd_unmap_memory() have incompatible implementations. The windows 
>> os::pd_map_memory() uses VirtualAlloc/VirtualProtect to create 
>> executable mapping and CreateFileMapping/MapViewOfFileEx for 
>> non-executable memory mapping, while os::pd_unmap_memory() just calls 
>> UnmapViewOfFile(). For executable mapping, UnmapViewOfFile() call 
>> fails because the memory was not mapped using 
>> CreateFileMapping/MapViewOfFileEx. The failure was observed with CDS 
>> when it tries to unmap shared executable 'mc’ region on windows-32 
>> platform.
>>
>> bug: JDK-8135097 <https://bugs.openjdk.java.net/browse/JDK-8135097>
>> webrev: http://cr.openjdk.java.net/~jiangli/8135097/webrev.00/
>>
>> Tested with JPRT, unit test.
>>
>> Thanks,
>> Jiangli
>>
>