RFR: 8288282: Zero-release build is broken after JDK-8279047 due to UseHeavyMonitors is read-only [v4]

[Aleksey Shipilev]

On Mon, 13 Jun 2022 10:41:22 GMT, Jie Fu <jiefu at openjdk.org> wrote:

>> Hi all,
>> 
>> Zero-release build is broken after JDK-8279047.
>> After JDK-8279047, `UseHeavyMonitors` becomes read-only in PRODUCT VMs.
>> 
>> But for Zero, `UseHeavyMonitors` needs to be reset if `DiagnoseSyncOnValueBasedClasses != 0`.
>> 
>>   // If lock diagnostics is needed, always call to runtime
>>   if (DiagnoseSyncOnValueBasedClasses != 0) {
>>     FLAG_SET_DEFAULT(UseHeavyMonitors, true);
>>   }
>> 
>> 
>> I never hear that people would DiagnoseSyncOnValueBasedClasses with zero vms.
>> So in order to expire `UseHeavyMonitors` for all PRODUCT VMs, I suggest disabling lock diagnostics for zero vms.
>> 
>> Thanks.
>> Best regards,
>> Jie
>
> Jie Fu has updated the pull request incrementally with one additional commit since the last revision:
> 
>   Disable lock diagnostics for all zero versions

Marked as reviewed by shade (Reviewer).

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PR: https://git.openjdk.org/jdk/pull/9138