Discussion on Fork/Join Semantics in Effect 3 vs. Effect 4 FiberRefs

import { NodeRuntime } from "@effect/platform-node"
import { Effect, Fiber, FiberRef, pipe } from "effect"

const log = Effect.gen(function*() {
  const v = yield* FiberRef.get(FiberRef.currentConcurrency);
  yield* Effect.log(v);
})

const program = Effect.gen(function*() {
  yield* log
  const fiber = yield* pipe(
    log,
    Effect.andThen(FiberRef.set(FiberRef.currentConcurrency, 2)),
    Effect.andThen(log),
    Effect.fork,
  )
  yield* Fiber.join(fiber);
  yield* log
})

program.pipe(
  NodeRuntime.runMain
)

12:58:36 PM - Found 0 errors. Watching for file changes.
[12:58:37.385] INFO (#1): unbounded
[12:58:37.387] INFO (#2): unbounded
[12:58:37.388] INFO (#2): 2
[12:58:37.388] INFO (#1): 2

import { Effect, Fiber, pipe, References } from "effect"

const log = Effect.gen(function*() {
  const v = yield* References.CurrentConcurrency
  yield* Effect.log(v)
})

const program = Effect.gen(function*() {
  yield* log
  const fiber = yield* pipe(
    log,
    Effect.provideService(References.CurrentConcurrency, 2),
    Effect.andThen(log),
    Effect.fork
  )
  yield* Fiber.join(fiber)
  yield* log
})

Effect.runFork(program)

[12:57:25.571] INFO (#1): unbounded
[12:57:25.577] INFO (#2): 2
[12:57:25.577] INFO (#2): unbounded
[12:57:25.577] INFO (#1): unbounded