[WIP] Remove deprecated scala.concurrent.forkjoin references #18262

[NeQuissimus]

• Replaced all instances of scala.concurrent.forkjoin.* with their corresponding classes in java.util.concurrent
• Removed one unused import of ThreadLocalRandom

This work fixed #18262.

Binary compatibility warnings will need to be addressed, copy from the discussion on #18262:

The following methods and type hierarchies are affected

akka.dispatch.BalancingDispatcher$SharingMailbox
akka.dispatch.ForkJoinExecutorConfigurator#AkkaForkJoinPool.this
akka.dispatch.ForkJoinExecutorConfigurator#ForkJoinExecutorServiceFactory.this
akka.dispatch.ForkJoinExecutorConfigurator#ForkJoinExecutorServiceFactory.threadFactory
akka.dispatch.ForkJoinExecutorConfigurator$AkkaForkJoinPool
akka.dispatch.ForkJoinExecutorConfigurator$AkkaForkJoinTask
akka.dispatch.ForkJoinExecutorConfigurator.validate
akka.dispatch.MonitorableThreadFactory#AkkaForkJoinWorkerThread.this
akka.dispatch.MonitorableThreadFactory$AkkaForkJoinWorkerThread
akka.dispatch.MonitorableThreadFactory.newThread

Raw log:

[info] akka-actor: found 13 potential binary incompatibilities while checking against com.typesafe.akka:akka-actor_2.11:2.3.15  (filtered 215)
[error]  * method threadFactory()scala.concurrent.forkjoin.ForkJoinPool#ForkJoinWorkerThreadFactory in class akka.dispatch.ForkJoinExecutorConfigurator#ForkJoinExecutorServiceFactory has a different result type in current version, where it is java.util.concurrent.ForkJoinPool#ForkJoinWorkerThreadFactory rather than scala.concurrent.forkjoin.ForkJoinPool#ForkJoinWorkerThreadFactory
[error]    filter with: ProblemFilters.exclude[IncompatibleResultTypeProblem]("akka.dispatch.ForkJoinExecutorConfigurator#ForkJoinExecutorServiceFactory.threadFactory")
[error]  * method this(akka.dispatch.ForkJoinExecutorConfigurator,scala.concurrent.forkjoin.ForkJoinPool#ForkJoinWorkerThreadFactory,Int)Unit in class akka.dispatch.ForkJoinExecutorConfigurator#ForkJoinExecutorServiceFactory's type is different in current version, where it is (akka.dispatch.ForkJoinExecutorConfigurator,java.util.concurrent.ForkJoinPool#ForkJoinWorkerThreadFactory,Int)Unit instead of (akka.dispatch.ForkJoinExecutorConfigurator,scala.concurrent.forkjoin.ForkJoinPool#ForkJoinWorkerThreadFactory,Int)Unit
[error]    filter with: ProblemFilters.exclude[IncompatibleMethTypeProblem]("akka.dispatch.ForkJoinExecutorConfigurator#ForkJoinExecutorServiceFactory.this")
[error]  * method this(akka.dispatch.ForkJoinExecutorConfigurator,scala.concurrent.forkjoin.ForkJoinPool#ForkJoinWorkerThreadFactory,Int,Boolean)Unit in class akka.dispatch.ForkJoinExecutorConfigurator#ForkJoinExecutorServiceFactory's type is different in current version, where it is (akka.dispatch.ForkJoinExecutorConfigurator,java.util.concurrent.ForkJoinPool#ForkJoinWorkerThreadFactory,Int,Boolean)Unit instead of (akka.dispatch.ForkJoinExecutorConfigurator,scala.concurrent.forkjoin.ForkJoinPool#ForkJoinWorkerThreadFactory,Int,Boolean)Unit
[error]    filter with: ProblemFilters.exclude[IncompatibleMethTypeProblem]("akka.dispatch.ForkJoinExecutorConfigurator#ForkJoinExecutorServiceFactory.this")
[error]  * method validate(java.util.concurrent.ThreadFactory)scala.concurrent.forkjoin.ForkJoinPool#ForkJoinWorkerThreadFactory in class akka.dispatch.ForkJoinExecutorConfigurator has a different result type in current version, where it is java.util.concurrent.ForkJoinPool#ForkJoinWorkerThreadFactory rather than scala.concurrent.forkjoin.ForkJoinPool#ForkJoinWorkerThreadFactory
[error]    filter with: ProblemFilters.exclude[IncompatibleResultTypeProblem]("akka.dispatch.ForkJoinExecutorConfigurator.validate")
[error]  * the type hierarchy of class akka.dispatch.ForkJoinExecutorConfigurator#AkkaForkJoinTask is different in current version. Missing types {java.lang.Object,scala.concurrent.forkjoin.ForkJoinTask}
[error]    filter with: ProblemFilters.exclude[MissingTypesProblem]("akka.dispatch.ForkJoinExecutorConfigurator$AkkaForkJoinTask")
[error]  * method newThread(scala.concurrent.forkjoin.ForkJoinPool)scala.concurrent.forkjoin.ForkJoinWorkerThread in class akka.dispatch.MonitorableThreadFactory in current version does not have a correspondent with same parameter signature among (java.util.concurrent.ForkJoinPool)java.util.concurrent.ForkJoinWorkerThread, (java.lang.Runnable)java.lang.Thread
[error]    filter with: ProblemFilters.exclude[IncompatibleMethTypeProblem]("akka.dispatch.MonitorableThreadFactory.newThread")
[error]  * the type hierarchy of class akka.dispatch.ForkJoinExecutorConfigurator#AkkaForkJoinPool is different in current version. Missing types {java.util.concurrent.AbstractExecutorService,scala.concurrent.forkjoin.ForkJoinPool}
[error]    filter with: ProblemFilters.exclude[MissingTypesProblem]("akka.dispatch.ForkJoinExecutorConfigurator$AkkaForkJoinPool")
[error]  * method this(Int,scala.concurrent.forkjoin.ForkJoinPool#ForkJoinWorkerThreadFactory,java.lang.Thread#UncaughtExceptionHandler)Unit in class akka.dispatch.ForkJoinExecutorConfigurator#AkkaForkJoinPool's type is different in current version, where it is (Int,java.util.concurrent.ForkJoinPool#ForkJoinWorkerThreadFactory,java.lang.Thread#UncaughtExceptionHandler)Unit instead of (Int,scala.concurrent.forkjoin.ForkJoinPool#ForkJoinWorkerThreadFactory,java.lang.Thread#UncaughtExceptionHandler)Unit
[error]    filter with: ProblemFilters.exclude[IncompatibleMethTypeProblem]("akka.dispatch.ForkJoinExecutorConfigurator#AkkaForkJoinPool.this")
[error]  * method this(Int,scala.concurrent.forkjoin.ForkJoinPool#ForkJoinWorkerThreadFactory,java.lang.Thread#UncaughtExceptionHandler,Boolean)Unit in class akka.dispatch.ForkJoinExecutorConfigurator#AkkaForkJoinPool's type is different in current version, where it is (Int,java.util.concurrent.ForkJoinPool#ForkJoinWorkerThreadFactory,java.lang.Thread#UncaughtExceptionHandler,Boolean)Unit instead of (Int,scala.concurrent.forkjoin.ForkJoinPool#ForkJoinWorkerThreadFactory,java.lang.Thread#UncaughtExceptionHandler,Boolean)Unit
[error]    filter with: ProblemFilters.exclude[IncompatibleMethTypeProblem]("akka.dispatch.ForkJoinExecutorConfigurator#AkkaForkJoinPool.this")
[error]  * the type hierarchy of class akka.dispatch.Mailbox is different in current version. Missing types {java.lang.Object}
[error]    filter with: ProblemFilters.exclude[MissingTypesProblem]("akka.dispatch.BalancingDispatcher$SharingMailbox")
[error]  * the type hierarchy of class akka.dispatch.MonitorableThreadFactory#AkkaForkJoinWorkerThread is different in current version. Missing types {java.lang.Thread,scala.concurrent.forkjoin.ForkJoinWorkerThread}
[error]    filter with: ProblemFilters.exclude[MissingTypesProblem]("akka.dispatch.MonitorableThreadFactory$AkkaForkJoinWorkerThread")
[error]  * method this(scala.concurrent.forkjoin.ForkJoinPool)Unit in class akka.dispatch.MonitorableThreadFactory#AkkaForkJoinWorkerThread's type is different in current version, where it is (java.util.concurrent.ForkJoinPool)Unit instead of (scala.concurrent.forkjoin.ForkJoinPool)Unit
[error]    filter with: ProblemFilters.exclude[IncompatibleMethTypeProblem]("akka.dispatch.MonitorableThreadFactory#AkkaForkJoinWorkerThread.this")

[akka-ci]

Can one of the repo owners verify this patch?

[drewhk]

OK TO TEST

[akka-ci]

Test FAILed.

[NeQuissimus]

Is your general workflow for you to schedule looking at this internally? I am not quite sure what should happen next :) The MiMa concerns are valid, which makes me think the MiMa exclusions should only be in effect for 2.5.x?!

[patriknw]

As mentioned in the issue I'm very skeptical to replacing this in a patch release. The behavior or performance profile might have changed. That is too risky to just drop-in to production systems.

Feel free to prove me wrong, but then I would like to see evidence that the implementations are almost identical, and I don't have time to do that investigation myself.

I have no problem switching for Akka 2.5

[NeQuissimus]

I will do some investigation. Should I find any difference, I will add the MiMa filters for 2.5

[NeQuissimus]

Looking at the implementations, they do seem to be slightly different. From what I can tell JDK 8 and Scala 2.11 have different versions of JSR166 included, which causes the difference.
It does not look like much but I agree with not wanting to change this in a 2.4.x release.

I will update the PR

[akka-ci]

Test FAILed.

[akka-ci]

Test FAILed.

[akka-ci]

Test FAILed.

[NeQuissimus]

This now only fails because we are still building a 2.4.x. I added the MIMA filters for 2.5.0.
A simple rebase against a 2.5.0 master should be enough to make this build pass.

[patriknw]

Thank you, @NeQuissimus
Since we have not created a branch for 2.5 development yet I will close this PR for now, but mention it's existence in the issue.

[NeQuissimus]

Sounds good, I can just re-send it once there is a 2.5 branch.