RFR: 8218169 - [AOT] Segmentation fault when running java with AOTed Graal in -Xcomp mode on windows

[Bob Vandette]

> On Feb 7, 2019, at 3:31 PM, Ekaterina Pavlova <ekaterina.pavlova at oracle.com> wrote:
> 
> I think hs-tier1 is not enough to verify this particular issue because the issue was not discovered by tier1 tests.
> Bob, in addition to standard testing please follow mach5 instructions provided in the bug report to test on windows.

I extracted the test from the bug report and ran it successfully on my local machine but I’ll submit the mach5
job just to be sure.  I wanted to know which tier would run the other AOT jtreg test on Windows just to
verify that I haven’t broken anything else.

Bob.


> 
> thanks,
> -katya
> 
> 
> On 2/7/19 12:22 PM, Vladimir Kozlov wrote:
>> hs-tier1 runs AOT tests (tier1_compiler_not_xcomp) on all x64 platforms.
>> Vladimir
>> On 2/7/19 9:53 AM, Bob Vandette wrote:
>>> Thanks, I’ll make the change.
>>> 
>>> Do you know which mach5 tier, if any, performs AOT testing on Windows?
>>> 
>>> Bob.
>>> 
>>> 
>>>> On Feb 7, 2019, at 12:31 PM, Vladimir Kozlov <vladimir.kozlov at oracle.com> wrote:
>>>> 
>>>> Hi Bob,
>>>> 
>>>> Very nice fix. Can you use #if INCLUDE_AOT instead of _WIN64 based on your description?
>>>> 
>>>> Thanks,
>>>> Vladimir
>>>> 
>>>> On 2/7/19 7:15 AM, Bob Vandette wrote:
>>>>> Please review this fix for a SEGV occurring when AOT is used on Windows.
>>>>> PROBLEM:
>>>>> The problem is caused by the fact that we're getting an implicit exception from the .text
>>>>> segment of an AOT generated library but the generated code in the DLL does not have
>>>>> any structured exception sections or unwind tables. The normal hotspot CodeCache works
>>>>> around this limitation by registering the entire code cache with RtlAddFunctionTable. In order
>>>>> to do this for AOT generated code, a DynamicCodeData structure would need to be generated
>>>>> in the text segment of the AOT library.
>>>>> BUG:
>>>>> https://bugs.openjdk.java.net/browse/JDK-8218169
>>>>> WEBREV:
>>>>> http://cr.openjdk.java.net/~bobv/8218169
>>>>> SOLUTION:
>>>>> Rather than modify the AOT implementation to generate a Windows specific data structure that
>>>>> requires a jmp out of the DLL code and into Hotspots exception handler, I chose a simpler solution
>>>>> that installs a VectoredException handler. This VectoredException handler is only installed if AOT
>>>>> is enabled.
>>>>> This handler examines the pc of the exception. If this pc is determined to be in either the
>>>>> codeCache or in AOT generated code, we pass control to the existing exception handler otherwise
>>>>> we allow the system to continue searching for other exception handlers.
>>>>> There were problems in the past with the use of VEH but at that time we made exclusive use of
>>>>> VEH and did not use them in conjunction with SEH.  Since I am only passing control to our
>>>>> existing handler when the pc is from one of our code sections, other code in the system can
>>>>> continue to use SEH.
>>>>> For more details, please see the bug comments.
>>>>> Bob.
>>> 
>