RFR: 8327138: Clean up status management in cdsConfig.hpp and CDS.java

[Ioi Lam]

On Tue, 5 Mar 2024 20:39:10 GMT, Calvin Cheung <ccheung at openjdk.org> wrote:

>> A few clean ups:
>> 
>> 1. Rename functions like "`s_loading_full_module_graph()` to `is_using_full_module_graph()`. The meaning of "loading" is not clear: it might be interpreted as to cover only the period where the artifact is being loaded, but not the period after the artifact is completely loaded. However, the function is meant to cover both periods, so "using" is a more precise term.
>> 
>> 2. The cumbersome sounding `disable_loading_full_module_graph()` is changed to `stop_using_full_module_graph()`, etc.
>> 
>> 3. The status of `is_using_optimized_module_handling()` is moved from metaspaceShared.hpp to cdsConfig.hpp, to be consolidated with other types of CDS status.
>> 
>> 4. The status of CDS was communicated to the Java class `jdk.internal.misc.CDS` by ad-hoc native methods. This is now changed to a single method, `CDS.getCDSConfigStatus()` that returns a bit field. That way we don't need to add a new native method for each type of status.
>> 
>> 5. `CDS.isDumpingClassList()` was a misnomer. It's changed to `CDS.isLoggingLambdaFormInvokers()`.
>
> src/hotspot/share/cds/cdsConfig.hpp line 94:
> 
>> 92:   static bool   is_dumping_full_module_graph()               { return CDS_ONLY(_is_dumping_full_module_graph) NOT_CDS(false); }
>> 93:   static void   stop_using_full_module_graph(const char* reason = nullptr) NOT_CDS_JAVA_HEAP_RETURN;
>> 94:   static bool     is_using_full_module_graph()                NOT_CDS_JAVA_HEAP_RETURN_(false);
> 
> Please align this with line #90.

Do you mean aligning like this: 


  static bool is_dumping_heap()                              NOT_CDS_JAVA_HEAP_RETURN_(false);
  static void stop_dumping_full_module_graph(const char* reason = nullptr) NOT_CDS_JAVA_HEAP_RETURN;
  static bool is_dumping_full_module_graph()                 { return CDS_ONLY(_is_dumping_full_module_graph) NOT_CDS(false); }
  static void stop_using_full_module_graph(const char* reason = nullptr) NOT_CDS_JAVA_HEAP_RETURN;
  static bool is_using_full_module_graph()                   NOT_CDS_JAVA_HEAP_RETURN_(false);


I think this is more messy, and you can't easily tell that these four functions are all related to the same feature (full_module_graph).

-------------

PR Review Comment: https://git.openjdk.org/jdk/pull/18095#discussion_r1513626841