RFR: JDK-8187597: WrongTypeException is occurred at CLHSDB jstack after JDK-8186837
Yasumasa Suenaga
yasuenag at gmail.com
Wed Sep 20 23:57:57 UTC 2017
2017/09/21 午前8:35 "David Holmes" <david.holmes at oracle.com>:
The opening announcement was somewhat premature. They created jdk10/hs but
we're not quite ready to start accepting changes yet.
Where can I get the opening announcement for jdk10/hs?
I will send review request after that.
Thanks,
Yasumasa
David
On 21/09/2017 8:44 AM, Yasumasa Suenaga wrote:
> Hi David,
>
> jdk10/hs has been opened [1].
> Could you push this change?
>
>
> Thanks,
>
> Yasumasa
>
>
> [1] http://mail.openjdk.java.net/pipermail/jdk10-dev/2017-Septem
> ber/000499.html
>
>
> On 2017/09/19 12:31, David Holmes wrote:
>
>> On 19/09/2017 1:19 PM, Yasumasa Suenaga wrote:
>>
>>> Thanks David,
>>>
>>> BTW, can I push this change after jdk10/master is opened?
>>> I cannot access JPRT.
>>>
>>
>> I think we'd probably prefer this to go into jdk10/hs - once it is open -
>> and for that you need a sponsor.
>>
>> Thanks,
>> David
>>
>>
>>> Yasumasa
>>>
>>>
>>> 2017/09/19 午後0:08 "David Holmes" <david.holmes at oracle.com <mailto:
>>> david.holmes at oracle.com>>:
>>>
>>> Hi Yasumasa,
>>>
>>> On 19/09/2017 12:55 PM, Yasumasa Suenaga wrote:
>>>
>>> Thanks Chris, Robbin,
>>>
>>> I'm waiting reviewer(s) for this change.
>>>
>>>
>>> Reviewed.
>>>
>>> This simply reverts the change of 8185102.
>>>
>>> Thanks,
>>> David
>>> -----
>>>
>>>
>>> Yasumasa
>>>
>>>
>>> 2017/09/19 午前7:14 "Chris Plummer" <chris.plummer at oracle.com
>>> <mailto:chris.plummer at oracle.com>
>>> <mailto:chris.plummer at oracle.com
>>> <mailto:chris.plummer at oracle.com>>>:
>>>
>>> Hi Yasumasa,
>>>
>>> Ok, I see now that CIntegerField is just an interface, so
>>> it's up to
>>> a class to implement getValue() to fetch the field. I'm a
>>> bit
>>> unclear on how that part works, but from responses by
>>> others, it
>>> seems this is ok.
>>>
>>> I've run all the tests I can find that use jstack or jhsdb,
>>> and the
>>> assert was not triggered. Probably need to have a NMethod
>>> on the
>>> stack to trigger the code you are fixing.
>>>
>>> thanks,
>>>
>>> Chris
>>>
>>>
>>> On 9/17/17 1:13 AM, Yasumasa Suenaga wrote:
>>>
>>> Hi Chris,
>>>
>>> I've tested this issue on Fedora 26 x86_64.
>>> I think we can sue CIntegerField at this point because
>>> CIntegerField is not specialized for various int size
>>> [1].
>>> In fact, CIntegerField had been used at this point [2],
>>> and HSDB
>>> worked fine.
>>>
>>>
>>> Thanks,
>>>
>>> Yasumasa
>>>
>>>
>>> [1]
>>> http://hg.openjdk.java.net/jdk10/master/file/fd36993f7bf5/
>>> src/jdk.hotspot.agent/share/classes/sun/jvm/hotspot/types/
>>> CIntegerField.java#l29
>>> <http://hg.openjdk.java.net/jdk10/master/file/fd36993f7bf5/
>>> src/jdk.hotspot.agent/share/classes/sun/jvm/hotspot/types/
>>> CIntegerField.java#l29>
>>> <http://hg.openjdk.java.net/jdk10/master/file/fd36993f7bf5/
>>> src/jdk.hotspot.agent/share/classes/sun/jvm/hotspot/types/
>>> CIntegerField.java#l29
>>> <http://hg.openjdk.java.net/jdk10/master/file/fd36993f7bf5/
>>> src/jdk.hotspot.agent/share/classes/sun/jvm/hotspot/types/
>>> CIntegerField.java#l29>>
>>> [2]
>>> http://hg.openjdk.java.net/jdk10/master/rev/cbfdbefc6ea3
>>> <http://hg.openjdk.java.net/jdk10/master/rev/cbfdbefc6ea3>
>>> <http://hg.openjdk.java.net/jdk10/master/rev/cbfdbefc6ea3
>>> <http://hg.openjdk.java.net/jdk10/master/rev/cbfdbefc6ea3>>
>>>
>>>
>>> On 2017/09/17 3:58, Chris Plummer wrote:
>>>
>>> Hi Yasumasa,
>>>
>>> Is this on a 32-bit system? I don't see how you
>>> could
>>> otherwise call getCIntegerField() on a long type.
>>> jlong is
>>> always 64-bit and long is (generally) 32-bit on
>>> 32-bit
>>> systems, and 64-bit on 64-bit systems, at least
>>> that seems
>>> to be the case with linux.
>>>
>>> From what I can see, _stack_traversal_mark is now
>>> the only
>>> long type in vmStructs.cpp. I don't know that we
>>> have a
>>> mechanism to safely fetch it on both 32-bit and
>>> 64-bit systems.
>>>
>>> _stack_traversal_mark seems to be a long because
>>> _traversals
>>> is also a long.
>>>
>>> static long
>>> _traversals; //
>>> Stack scan count, also sweep ID.
>>>
>>> This too might be considered a bug. I'm not sure
>>> why you
>>> would want the size of this field to vary between
>>> 32-bit and
>>> 64-bit systems (adding compiler-dev to help answer
>>> that).
>>>
>>> So, while I would agree that your fix is generally
>>> in the
>>> right direction, I think we first need to revisit
>>> the use of
>>> long for these fields. If they can be changed to an
>>> int,
>>> then your fix is correct (pending the changes to
>>> int). If
>>> not, then maybe we need getCLongField() support.
>>>
>>> And lastly, we really should have a test to detect
>>> this bug.
>>> Maybe we already do, and it is failing but is going
>>> unnoticed for some reason. I'll try to look into
>>> that some
>>> more on Monday.
>>>
>>> thanks,
>>>
>>> Chris
>>>
>>> On 9/16/17 5:20 AM, Yasumasa Suenaga wrote:
>>>
>>> Hi all,
>>>
>>> I tried to get thread dump via jstack command
>>> on CLHSDB.
>>> But it was failed as below:
>>>
>>> ```
>>> Caused by:
>>> sun.jvm.hotspot.types.WrongTypeException:
>>> field "_stack_traversal_mark" in type nmethod
>>> is not of
>>> type jlong, but instead of type long
>>> at
>>> jdk.hotspot.agent/sun.jvm.hotspot.types.basic.BasicType.getField(BasicType.java:206)
>>>
>>> at
>>> jdk.hotspot.agent/sun.jvm.hotspot.types.basic.BasicType.getField(BasicType.java:212)
>>>
>>> at
>>> jdk.hotspot.agent/sun.jvm.hotspot.types.basic.BasicType.getJLongField(BasicType.java:249)
>>>
>>> at
>>> jdk.hotspot.agent/sun.jvm.hotspot.code.NMethod.initialize(NMethod.java:108)
>>>
>>> at
>>> jdk.hotspot.agent/sun.jvm.hotspot.code.NMethod.access$000(NMethod.java:35)
>>>
>>> at
>>> jdk.hotspot.agent/sun.jvm.hotspot.code.NMethod$1.update(NMet
>>> hod.java:81)
>>>
>>> at
>>> jdk.hotspot.agent/sun.jvm.hotspot.runtime.VM.registerVMInitializedObserver(VM.java:451)
>>>
>>> at
>>> jdk.hotspot.agent/sun.jvm.hotspot.code.NMethod.<clinit>(NMet
>>> hod.java:79)
>>> ... 23 more
>>> ```
>>>
>>> I think this exception is caused by JDK-8186837.
>>> This changeset has changed the type of
>>> `nmethod::_stack_traversal_mark` to `long` from
>>> `jlong`.
>>>
>>> SA should follow this change.
>>>
>>> I uploaded a webrev for this issue. This webrev
>>> is
>>> generated from consolidated repo (jdk10/master).
>>> Could you review it?
>>>
>>> http://cr.openjdk.java.net/~ysuenaga/JDK-8187597/webrev.00/
>>> <http://cr.openjdk.java.net/~ysuenaga/JDK-8187597/webrev.00/>
>>> <http://cr.openjdk.java.net/~ysuenaga/JDK-8187597/webrev.00/
>>> <http://cr.openjdk.java.net/~ysuenaga/JDK-8187597/webrev.00/>>
>>>
>>>
>>> I cannot access JPRT. So I need reviewer.
>>>
>>>
>>> Thanks,
>>>
>>> Yasumasa
>>>
>>>
>>>
>>>
>>>
>>>
>>>
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