RFR (S): 8228857: Refactor PlatformMonitor into PlatformMutex and PlatformMonitor

[David Holmes]

Thanks Dean!

David

On 6/08/2019 12:32 pm, dean.long at oracle.com wrote:
> Looks good to me.
> 
> dl
> 
> On 8/5/19 6:49 PM, David Holmes wrote:
>> Ping!
>>
>> On 2/08/2019 9:03 am, David Holmes wrote:
>>> Bug: https://bugs.openjdk.java.net/browse/JDK-8228857
>>> webrev: http://cr.openjdk.java.net/~dholmes/8228857/webrev/
>>>
>>> As suggested by Per Liden when PlatformMonitor was introduced by 
>>> JDK-8210832 we should refactor PlatformMonitor into a simpler 
>>> PlatformMutex extended by PlatformMonitor. That would potentially 
>>> allow other synchronization objects e.g. Zlocks, to be replaced by a 
>>> suitable PlatformX class, and allows us to redefine JVM_RawMonitor 
>>> support to use it (forthcoming change).
>>>
>>> The refactoring would be obvious and simple if not for the macOS 
>>> PThread allocation bug workaround. I had to change the Posix variant 
>>> so that we only use the Impl helper class on macOS, so that we can 
>>> separate the allocation of the pthread_mutex_t and pthread_cond_t. 
>>> For macOS both get allocated in the PlatformMutex.
>>>
>>> There are not actual usage changes in this RFE.
>>>
>>> Testing: mach5 tiers 1-3
>>>
>>> Thanks,
>>> David
>>> -----
>