RFR: 8345139: Fix bugs and inconsistencies in the Provider services map [v4]

[Martin Balao]

On Tue, 11 Feb 2025 23:33:49 GMT, Francisco Ferrari Bihurriet <fferrari at openjdk.org> wrote:

>> Hi, this pull request implements the fixes for bugs and inconsistencies described in [JDK-8345139](https://bugs.openjdk.org/browse/JDK-8345139 "Fix bugs and inconsistencies in the Provider services map").
>> 
>> #### New services map design
>> 
>> Here is the high-level hierarchy of the new services map design:
>> 
>> * `servicesMap` (`ServicesMap`)
>>     * Instances
>>         * `impl` (`ServicesMapImpl`)
>>             * `services` (`Map<ServiceKey, Service>`): unifies the previous `serviceMap` and `legacyMap`
>>             * `legacySvcKeys` (`Set<ServiceKey>`): set indicating which keys in `services` correspond to the Legacy API
>>             * `serviceProps` (`Map<ServiceKey, String>`): keeps track of the _provider Hashtable entries_ that originated services entries <sup>(1)</sup>
>>             * `serviceAttrProps` (`Map<ServiceKey, Map<UString, String>>`): keeps track of the _provider Hashtable entries_ that originated service attributes <sup>(1)</sup>
>>         * `serviceSet` (`AtomicReference<Set<Service>>`): part of a lock-free mechanism to implement a consistent version of the `getServices()` readers method
>>     * Writers' methods (for providers registration)
>>         * `Current asCurrent()`: returns `impl` seen as a `Current` interface implementer
>>             * `putService(Service svc)`
>>             * `removeService(Service svc)`
>>         * `Legacy asLegacy()`: returns `impl` seen as a `Legacy` interface implementer
>>             * `putClassName(ServiceKey key, String className, String propKey)`
>>             * `putAlias(ServiceKey key, ServiceKey aliasKey, String propKey)`
>>             * `putAttribute(ServiceKey key, String attrName, String attrValue, String propKey)`
>>             * `remove(ServiceKey key, String className)`
>>             * `removeAlias(ServiceKey key, ServiceKey aliasKey)`
>>             * `removeAttribute(ServiceKey key, String attrName, String attrValue)`
>>     * Readers' methods (for services users and `GetInstance` APIs)
>>         * `Set<Service> getServices()`
>>         * `Service getService(ServiceKey key)`
>>     * Other methods: default and copy constructors, `void clear()`
>> 
>> (1): to maintain the consistency between the provider's `servicesMap` and its _Hashtable entries_, even if Legacy API updates occur through _properties_ with different casing, or aliases instead of main algorithms.
>> 
>> #### Testing
>> 
>> As part of our testing, we observed all the tests pass in the following categories:
>> 
>> * `jdk:tier1` (see [...
>
> Francisco Ferrari Bihurriet has updated the pull request with a new target base due to a merge or a rebase. The pull request now contains four commits:
> 
>  - Merge openjdk/master into JDK-8345139
>    
>    Fix conflict caused by e20bd018c4046870d0cf632bb8e5440cb9f5c3c2:
>      1. Ignore the change, as this had already been identified and fixed
>         (see JDK-8345139, section 3.1).
>      2. Remove the test, as it is already covered by
>         ServicesConsistency::testInvalidServiceNotReturned.
>      3. Add the corresponding bug ID to ServicesConsistency.
>    
>    Co-authored-by: Francisco Ferrari Bihurriet <fferrari at redhat.com>
>    Co-authored-by: Martin Balao Alonso <mbalao at redhat.com>
>  - ServicesMapImpl class and Current, Legacy interfaces removed.
>    
>    Co-authored-by: Martin Balao Alonso <mbalao at redhat.com>
>    Co-authored-by: Francisco Ferrari Bihurriet <fferrari at redhat.com>
>  - Copyright update.
>    
>    Co-authored-by: Martin Balao Alonso <mbalao at redhat.com>
>    Co-authored-by: Francisco Ferrari Bihurriet <fferrari at redhat.com>
>  - 8345139: Fix bugs and inconsistencies in the Provider services map
>    
>    Co-authored-by: Francisco Ferrari Bihurriet <fferrari at redhat.com>
>    Co-authored-by: Martin Balao <mbalao at redhat.com>

The reason for having `Current` and `Legacy` interfaces was only to internally group methods and stress the distinction. We have now removed it and proposed a flat hierarchy for the `ServicesMap` (without the interfaces and impl class).

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PR Comment: https://git.openjdk.org/jdk/pull/22613#issuecomment-2652335492