RFR: 8135097: Unmap failure for executable memory on windows

[Jiangli Zhou]

Thanks Ioi!

Jiangli

> On Sep 8, 2015, at 12:43 PM, Ioi Lam <ioi.lam at oracle.com> 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
>> 
>