RFR (S): 8228858: Reimplement JVM_RawMonitors to use PlatformMutex

[David Holmes]

Thanks Dan!

David

On 15/08/2019 1:02 am, Daniel D. Daugherty wrote:
> On 8/14/19 8:32 AM, David Holmes wrote:
>> bug: https://bugs.openjdk.java.net/browse/JDK-8228858
>> webrev: http://cr.openjdk.java.net/~dholmes/8228858/webrev/
> 
> src/hotspot/share/prims/jvm.cpp
>      No comments.
> 
> src/hotspot/share/runtime/mutex.cpp
>      No comments.
> 
> src/hotspot/share/runtime/mutex.hpp
>      L55:   // The rank native was only for use in Mutex's created by 
> JVM_RawMonitorCreate,
>          nit typo: s/Mutex's/Mutexes/
>          (Not your typo, but...)
> 
> src/hotspot/share/runtime/park.cpp
>      No comments.
> 
> Thumbs up. No need to see a new webrev if you decide to fix the typo.
> 
> Dan
> 
> 
>>
>> A JVM_RawMonitor  (not to be confused with JvmtiRawMonitor) is a 
>> simple mutex (despite the name) currently implemented via two special 
>> entry points in the VM Monitor code. This fix changes that so that a 
>> JVM_RawMonitor is just a PlatformMutex, enabling us to delete the 
>> special Monitor code.
>>
>> There are two clients of JVM_RawMonitor:
>> - the native Zip library provided by the JDK and used by the JVM 
>> during classloading
>> - AWT debug code
>>
>> The first should be tested by using the VM. :) The second I don't 
>> know. But the functionality we're testing is already present so 
>> there's sufficient coverage just by testing one client.
>>
>> Testing: tiers 1 - 3 on Linux/macOS/Window x64, Solaris sparcv9
>>
>> Thanks,
>> David
>