RFR (S) 8230003: Make Monitor inherit from Mutex

[coleen.phillimore at oracle.com]

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
>>
>>
>> *
>> *