RFR (S) 8230003: Make Monitor inherit from Mutex

[coleen.phillimore at oracle.com]

Thanks David!
Coleen

On 8/22/19 9:26 AM, David Holmes wrote:
> Hi Coleen,
>
> Thanks for making the changes. Incremental webrev looks good!
>
> David
>
> On 22/08/2019 10:44 pm, coleen.phillimore at oracle.com wrote:
>>
>>
>> On 8/22/19 2:45 AM, David Holmes wrote:
>>> Hi Coleen,
>>>
>>> On 22/08/2019 12:52 pm, coleen.phillimore at oracle.com wrote:
>>>> Summary: Reverse inheritance that makes more sense.
>>>>
>>>> See bug for more description.  Tested with hs-tier1-3 with 
>>>> linux-x64-debug and hs-tier1 on Oracle platforms.
>>>>
>>>> open webrev at 
>>>> http://cr.openjdk.java.net/~coleenp/2019/8230003.01/webrev
>>>> bug link https://bugs.openjdk.java.net/browse/JDK-8230003
>>>
>>> src/hotspot/share/runtime/interfaceSupport.inline.hpp
>>>
>>> !   Mutex** _in_flight_monitor_adr;
>>>
>>> It looks a little odd to still have "monitor" in the local variable 
>>> and thread field name. That's another 18 changes to make. Separate 
>>> cleanup okay.
>>>
>>
>> I fixed it, it was a easy additional change to look at.
>>> ---
>>>
>>> src/hotspot/share/runtime/mutex.hpp
>>>
>>> // The default length of monitor name was originally chosen to be 64 
>>> to avoid
>>> // false sharing. Now, PaddedMonitor is available for this purpose.
>>> // TODO: Check if _name[MONITOR_NAME_LEN] should better get replaced 
>>> by const char*.
>>> static const int MONITOR_NAME_LEN = 64;
>>>
>>> s/monitor/mutex throughout?
>> I fixed this too.
>>
>> We should have an RFE for this.
>>
>>>
>>> ---
>>>
>>> src/hotspot/share/runtime/mutex.cpp
>>>
>>>       log_trace(vmmonitor)("JavaThread " INTPTR_FORMAT " on %d 
>>> attempt trying to acquire vmmonitor %s", p2i(self), retry_cnt, _name);
>>>
>>> There's only a single logging line in all the mutex/monitor code. Is 
>>> it worth changing vmmonitor to vmmutex ?
>>
>> I did this too.
>>
>> And removed the comment that Robbin pointed out.
>>
>> Rebuilt, will run tier1 sanity.
>>
>> incremental: 
>> http://cr.openjdk.java.net/~coleenp/2019/8230003.02.incr/webrev
>> full: http://cr.openjdk.java.net/~coleenp/2019/8230003.02/webrev
>>
>> Thanks,
>> Coleen
>>>
>>> Thanks,
>>> David
>>> -----
>>>
>>>> Thanks,
>>>> Coleen
>>>>
>>>>
>>>> *
>>>> *
>>