RFR: 8225788: Dead code in thread and safepoint

[coleen.phillimore at oracle.com]

On 6/18/19 12:34 PM, Daniel D. Daugherty wrote:
> On 6/14/19 8:29 AM, Robbin Ehn wrote:
>> Hi all, please review.
>>
>> Removing some dead code.
>>
>> Code:
>> http://cr.openjdk.java.net/~rehn/8225788/webrev/index.html
>
> src/hotspot/share/runtime/safepoint.hpp
>     No comments.
>
> src/hotspot/share/runtime/safepoint.cpp
>     No comments.
>
> src/hotspot/share/runtime/thread.hpp
>     No comments.
>
> src/hotspot/share/runtime/thread.cpp
>     Same question as David H. about the usefulness of calling
>     JavaThread::trace_oops() from the debugger. I think that Coleen
>     and Lois do the most bad oop hunting on the Runtime team

I've never used this function to find a bad oop on the stack from the 
debugger.  I'm trying to think of a scenario where I would use this 
function.  Generally things croak in GC when there's a bad oop and you 
see where it is in the frame from that information.  It looks like this 
code was added in 2011 as part of a bug hunt for an SA bug.   Also, 
PrintAndVerifyOopClosure can be removed.

Coleen


>
> src/hotspot/share/runtime/vmOperations.hpp
>     Hmmm... I wonder if the calling thread's priority is useful
>     for debugging safepoint starvation issues. David H. has been
>     in the thread priority code previously...
>
> src/hotspot/share/runtime/vmOperations.cpp
>     No comments.
>
> src/hotspot/share/compiler/compileBroker.cpp
>     Ummmm... So you're deleting the code that is recording when
>     a JavaThread is blocked on compilation. Of course, that
>     makes the setter and the field dead, but you made it that
>     way. I don't see any explanation in the bug report or in
>     the code review request explaining why it is no longer
>     useful to record this info.
>
>     This might be useful state information when debugging.
>
> src/hotspot/share/runtime/vframe_hp.cpp
>     No comments.
>
> src/hotspot/share/runtime/vmThread.cpp
>     No comments.
>
> Thumbs up! However, other folks might have different opinions
> about some of the stuff you are deleting.
>
> Dan
>
>
>> Issue:
>> https://bugs.openjdk.java.net/browse/JDK-8225788
>>
>> Thanks, Robbin
>