Created
November 17, 2023 11:40
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Minimization of hanging caused by canceling a Doobie transaction whilst inside `WeakAsync.liftK`
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//> using scala "3.3.1" | |
//> using dep "org.typelevel::cats-effect::3.5.2" | |
import cats.* | |
import cats.syntax.all.* | |
import cats.effect.* | |
import cats.effect.std.Dispatcher | |
import scala.concurrent.duration.* | |
object Repro extends IOApp.Simple: | |
val liftK: Resource[IO, IO ~> IO] = | |
Dispatcher.parallel[IO].map { dispatcher => | |
new (IO ~> IO) { | |
def apply[T]( | |
fa: IO[T] | |
) = | |
IO.fromFutureCancelable { | |
IO.uncancelable { poll => | |
poll(IO.delay(dispatcher.unsafeToFutureCancelable(fa))).map { | |
case (fut, cancel) => | |
( | |
fut, | |
IO.fromFuture(IO.delay(cancel())) | |
) | |
} | |
} | |
} | |
} | |
} | |
val run = | |
liftK.use { lift => | |
val run = lift(IO.sleep(2.seconds)).timeoutTo(1.micros, IO.unit) >> IO.println( | |
"-------------------------" | |
) | |
List.fill(100)(run).sequence.void | |
} | |
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