Re: RFR: 8330465: Stable Values and Collections (Internal) [v16]

2024-05-17 Thread Per Minborg 
On Thu, 16 May 2024 12:48:24 GMT, Per Minborg  wrote:

>> # Stable Values & Collections (Internal)
>> 
>> ## Summary
>> This PR proposes to introduce an internal _Stable Values & Collections_ API, 
>> which provides immutable value holders where elements are initialized _at 
>> most once_. Stable Values & Collections offer the performance and safety 
>> benefits of final fields while offering greater flexibility as to the timing 
>> of initialization.
>> 
>> ## Goals
>>  * Provide an easy and intuitive API to describe value holders that can 
>> change at most once.
>>  * Decouple declaration from initialization without significant footprint or 
>> performance penalties.
>>  * Reduce the amount of static initializer and/or field initialization code.
>>  * Uphold integrity and consistency, even in a multi-threaded environment.
>>  
>> For more details, see the draft JEP: https://openjdk.org/jeps/8312611
>> 
>> ## Performance 
>> Performance compared to instance variables using two `AtomicReference` and 
>> two protected by double-checked locking under concurrent access by all 
>> threads:
>> 
>> 
>> Benchmark  Mode  Cnt  Score  
>> Error   Units
>> StableBenchmark.atomicthrpt   10259.478 ?   
>> 36.809  ops/us
>> StableBenchmark.dcl   thrpt   10225.710 ?   
>> 26.638  ops/us
>> StableBenchmark.stablethrpt   10   4382.478 ? 
>> 1151.472  ops/us <- StableValue significantly faster
>> 
>> 
>> Performance compared to static variables protected by `AtomicReference`, 
>> class-holder idiom holder, and double-checked locking (all threads):
>> 
>> 
>> Benchmark  Mode  Cnt  Score  
>> Error   Units
>> StableStaticBenchmark.atomic  thrpt   10   6487.835 ?  
>> 385.639  ops/us
>> StableStaticBenchmark.dcl thrpt   10   6605.239 ?  
>> 210.610  ops/us
>> StableStaticBenchmark.stable  thrpt   10  14338.239 ? 
>> 1426.874  ops/us
>> StableStaticBenchmark.staticCHI   thrpt   10  13780.341 ? 
>> 1839.651  ops/us
>> 
>> 
>> Performance for stable lists (thread safe) in both instance and static 
>> contexts whereby we access a single value compared to `ArrayList` instances 
>> (which are not thread-safe) (all threads):
>> 
>> 
>> Benchmark  Mode  Cnt  Score  
>> Error   Units
>> StableListElementBenchmark.instanceArrayList  thrpt   10   5812.992 ? 
>> 1169.730  ops/us
>> StableListElementBenchmark.instanceList   thrpt   10   4818.643 ?  
>> 704.893  ops/us
>> StableListElementBenchmark...
>
> Per Minborg has updated the pull request incrementally with one additional 
> commit since the last revision:
> 
>   Fix copyringht issues

> _Mailing list message from [Olexandr 
> Rotan](mailto:rotanolexandr...@gmail.com) on 
> [compiler-dev](mailto:compiler-...@mail.openjdk.org):_
> 
> Is it possible to make stable values and collections Serializable? I see 
> various applications for this feature in entity classes as a way to preserve 
> immutability of entity fields and at the same time not break current JPA 
> specifications. It is a *very* common task in commercial development. Current 
> workarounds lack either thread safety or performance, and this looks like a 
> really good solution for both of those problems. However, unless StableValue 
> is serializable, it is really unlikely that JPA will adopt them (we have 
> precedent with Optional).
> 
> On Thu, May 16, 2024 at 5:07?PM Per Minborg  wrote:
> 
> -- next part -- An HTML attachment was scrubbed... 
> URL: 
> 

`Serializable` is on the list to explore.

-

PR Comment: https://git.openjdk.org/jdk/pull/18794#issuecomment-2116840097

Re: RFR: 8330465: Stable Values and Collections (Internal) [v16]

2024-05-16 Thread Olexandr Rotan 
Is it possible to make stable values and collections Serializable? I see
various applications for this feature in entity classes as a way to
preserve immutability of entity fields and at the same time not break
current JPA specifications. It is a *very* common task in commercial
development. Current workarounds lack either thread safety or performance,
and this looks like a really good solution for both of those problems.
However, unless StableValue is serializable, it is really unlikely that JPA
will adopt them (we have precedent with Optional).

On Thu, May 16, 2024 at 5:07 PM Per Minborg  wrote:

> On Thu, 16 May 2024 12:48:24 GMT, Per Minborg 
> wrote:
>
> >> # Stable Values & Collections (Internal)
> >>
> >> ## Summary
> >> This PR proposes to introduce an internal _Stable Values & Collections_
> API, which provides immutable value holders where elements are initialized
> _at most once_. Stable Values & Collections offer the performance and
> safety benefits of final fields while offering greater flexibility as to
> the timing of initialization.
> >>
> >> ## Goals
> >>  * Provide an easy and intuitive API to describe value holders that can
> change at most once.
> >>  * Decouple declaration from initialization without significant
> footprint or performance penalties.
> >>  * Reduce the amount of static initializer and/or field initialization
> code.
> >>  * Uphold integrity and consistency, even in a multi-threaded
> environment.
> >>
> >> For more details, see the draft JEP: https://openjdk.org/jeps/8312611
> >>
> >> ## Performance
> >> Performance compared to instance variables using two `AtomicReference`
> and two protected by double-checked locking under concurrent access by all
> threads:
> >>
> >>
> >> Benchmark  Mode  Cnt  Score
>   Error   Units
> >> StableBenchmark.atomicthrpt   10259.478 ?
>  36.809  ops/us
> >> StableBenchmark.dcl   thrpt   10225.710 ?
>  26.638  ops/us
> >> StableBenchmark.stablethrpt   10   4382.478 ?
> 1151.472  ops/us <- StableValue significantly faster
> >>
> >>
> >> Performance compared to static variables protected by
> `AtomicReference`, class-holder idiom holder, and double-checked locking
> (all threads):
> >>
> >>
> >> Benchmark  Mode  Cnt  Score
>   Error   Units
> >> StableStaticBenchmark.atomic  thrpt   10   6487.835 ?
> 385.639  ops/us
> >> StableStaticBenchmark.dcl thrpt   10   6605.239 ?
> 210.610  ops/us
> >> StableStaticBenchmark.stable  thrpt   10  14338.239 ?
> 1426.874  ops/us
> >> StableStaticBenchmark.staticCHI   thrpt   10  13780.341 ?
> 1839.651  ops/us
> >>
> >>
> >> Performance for stable lists (thread safe) in both instance and static
> contexts whereby we access a single value compared to `ArrayList` instances
> (which are not thread-safe) (all threads):
> >>
> >>
> >> Benchmark  Mode  Cnt  Score
>   Error   Units
> >> StableListElementBenchmark.instanceArrayList  thrpt   10   5812.992 ?
> 1169.730  ops/us
> >> StableListElementBenchmark.instanceList   thrpt   10   4818.643 ?
> 704.893  ops/us
> >> StableListElementBenchmark...
> >
> > Per Minborg has updated the pull request incrementally with one
> additional commit since the last revision:
> >
> >   Fix copyringht issues
>
> Here are some updated benchmark graphs where we sum two instance variables
> of different sorts (higher is better):
>
> ![image](
> https://github.com/openjdk/jdk/assets/7457876/d82561d6-e803-4345-b6d2-6b0402e60211
> )
>
> -
>
> PR Comment: https://git.openjdk.org/jdk/pull/18794#issuecomment-2115343828
>

Re: RFR: 8330465: Stable Values and Collections (Internal) [v16]

2024-05-16 Thread Per Minborg 
On Thu, 16 May 2024 12:48:24 GMT, Per Minborg  wrote:

>> # Stable Values & Collections (Internal)
>> 
>> ## Summary
>> This PR proposes to introduce an internal _Stable Values & Collections_ API, 
>> which provides immutable value holders where elements are initialized _at 
>> most once_. Stable Values & Collections offer the performance and safety 
>> benefits of final fields while offering greater flexibility as to the timing 
>> of initialization.
>> 
>> ## Goals
>>  * Provide an easy and intuitive API to describe value holders that can 
>> change at most once.
>>  * Decouple declaration from initialization without significant footprint or 
>> performance penalties.
>>  * Reduce the amount of static initializer and/or field initialization code.
>>  * Uphold integrity and consistency, even in a multi-threaded environment.
>>  
>> For more details, see the draft JEP: https://openjdk.org/jeps/8312611
>> 
>> ## Performance 
>> Performance compared to instance variables using two `AtomicReference` and 
>> two protected by double-checked locking under concurrent access by all 
>> threads:
>> 
>> 
>> Benchmark  Mode  Cnt  Score  
>> Error   Units
>> StableBenchmark.atomicthrpt   10259.478 ?   
>> 36.809  ops/us
>> StableBenchmark.dcl   thrpt   10225.710 ?   
>> 26.638  ops/us
>> StableBenchmark.stablethrpt   10   4382.478 ? 
>> 1151.472  ops/us <- StableValue significantly faster
>> 
>> 
>> Performance compared to static variables protected by `AtomicReference`, 
>> class-holder idiom holder, and double-checked locking (all threads):
>> 
>> 
>> Benchmark  Mode  Cnt  Score  
>> Error   Units
>> StableStaticBenchmark.atomic  thrpt   10   6487.835 ?  
>> 385.639  ops/us
>> StableStaticBenchmark.dcl thrpt   10   6605.239 ?  
>> 210.610  ops/us
>> StableStaticBenchmark.stable  thrpt   10  14338.239 ? 
>> 1426.874  ops/us
>> StableStaticBenchmark.staticCHI   thrpt   10  13780.341 ? 
>> 1839.651  ops/us
>> 
>> 
>> Performance for stable lists (thread safe) in both instance and static 
>> contexts whereby we access a single value compared to `ArrayList` instances 
>> (which are not thread-safe) (all threads):
>> 
>> 
>> Benchmark  Mode  Cnt  Score  
>> Error   Units
>> StableListElementBenchmark.instanceArrayList  thrpt   10   5812.992 ? 
>> 1169.730  ops/us
>> StableListElementBenchmark.instanceList   thrpt   10   4818.643 ?  
>> 704.893  ops/us
>> StableListElementBenchmark...
>
> Per Minborg has updated the pull request incrementally with one additional 
> commit since the last revision:
> 
>   Fix copyringht issues

Here are some updated benchmark graphs where we sum two instance variables of 
different sorts (higher is better):

![image](https://github.com/openjdk/jdk/assets/7457876/d82561d6-e803-4345-b6d2-6b0402e60211)

-

PR Comment: https://git.openjdk.org/jdk/pull/18794#issuecomment-2115343828

Re: RFR: 8330465: Stable Values and Collections (Internal) [v16]

2024-05-16 Thread Per Minborg 
> # Stable Values & Collections (Internal)
> 
> ## Summary
> This PR proposes to introduce an internal _Stable Values & Collections_ API, 
> which provides immutable value holders where elements are initialized _at 
> most once_. Stable Values & Collections offer the performance and safety 
> benefits of final fields while offering greater flexibility as to the timing 
> of initialization.
> 
> ## Goals
>  * Provide an easy and intuitive API to describe value holders that can 
> change at most once.
>  * Decouple declaration from initialization without significant footprint or 
> performance penalties.
>  * Reduce the amount of static initializer and/or field initialization code.
>  * Uphold integrity and consistency, even in a multi-threaded environment.
>  
> For more details, see the draft JEP: https://openjdk.org/jeps/8312611
> 
> ## Performance 
> Performance compared to instance variables using two `AtomicReference` and 
> two protected by double-checked locking under concurrent access by all 
> threads:
> 
> 
> Benchmark  Mode  Cnt  Score  
> Error   Units
> StableBenchmark.atomicthrpt   10259.478 ?   
> 36.809  ops/us
> StableBenchmark.dcl   thrpt   10225.710 ?   
> 26.638  ops/us
> StableBenchmark.stablethrpt   10   4382.478 ? 
> 1151.472  ops/us <- StableValue significantly faster
> 
> 
> Performance compared to static variables protected by `AtomicReference`, 
> class-holder idiom holder, and double-checked locking (all threads):
> 
> 
> Benchmark  Mode  Cnt  Score  
> Error   Units
> StableStaticBenchmark.atomic  thrpt   10   6487.835 ?  
> 385.639  ops/us
> StableStaticBenchmark.dcl thrpt   10   6605.239 ?  
> 210.610  ops/us
> StableStaticBenchmark.stable  thrpt   10  14338.239 ? 
> 1426.874  ops/us
> StableStaticBenchmark.staticCHI   thrpt   10  13780.341 ? 
> 1839.651  ops/us
> 
> 
> Performance for stable lists (thread safe) in both instance and static 
> contexts whereby we access a single value compared to `ArrayList` instances 
> (which are not thread-safe) (all threads):
> 
> 
> Benchmark  Mode  Cnt  Score  
> Error   Units
> StableListElementBenchmark.instanceArrayList  thrpt   10   5812.992 ? 
> 1169.730  ops/us
> StableListElementBenchmark.instanceList   thrpt   10   4818.643 ?  
> 704.893  ops/us
> StableListElementBenchmark.staticArrayListthrpt   10   7614.741 ?  
> 564.777  ops/us
> StableListElementBe...

Per Minborg has updated the pull request incrementally with one additional 
commit since the last revision:

  Fix copyringht issues

-

Changes:
  - all: https://git.openjdk.org/jdk/pull/18794/files
  - new: https://git.openjdk.org/jdk/pull/18794/files/2af0168e..ec7c92cd

Webrevs:
 - full: https://webrevs.openjdk.org/?repo=jdk=18794=15
 - incr: https://webrevs.openjdk.org/?repo=jdk=18794=14-15

  Stats: 206 lines in 13 files changed: 200 ins; 1 del; 5 mod
  Patch: https://git.openjdk.org/jdk/pull/18794.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/18794/head:pull/18794

PR: https://git.openjdk.org/jdk/pull/18794