zio mapZIOParUnordered does not respect parallelism

mapZIOParUnordered does not respect parallelism

Open adrian-salajan opened this issue 10 months ago • 4 comments

I am surprised of what this program using mapZIOParUnordered outputs

  override def run: ZIO[Any with ZIOAppArgs with Scope, Any, Any] = for {
    _ <- ZIO.debug("start")
    _ <- ZStream
      .iterate[Int](0)(n => n +1)
      .mapZIOParUnordered(2){ _ =>
        ZIO.debug("tick").delay(1.second)
      }.runDrain.zipParLeft(ZIO.debug("----").delay(2.seconds).forever)

  } yield ()

the number of ticks printed between the ----- is: 2, 7, 11, 15, 19, 23 .... while if instead of mapZIOParUnordered(2) i use mapZioPar(2) ticks printed is: 2, 6, 6, 6, 6. Here i would expect it to be 4, 4, 4, 4 but at least it does not keep increasing

Apr 16 '24 06:04 adrian-salajan

/bounty $100

May 08 '24 17:05 jdegoes

💎 $100 bounty • ZIO

Steps to solve:

Start working: Comment /attempt #8753 with your implementation plan
Submit work: Create a pull request including /claim #8753 in the PR body to claim the bounty
Receive payment: 100% of the bounty is received 2-5 days post-reward. Make sure you are eligible for payouts

Thank you for contributing to zio/zio!

Add a bounty • Share on socials