Method start

packages/effect/src/internal/fiberRuntime.ts:998–1019

* Begins execution of the effect associated with this fiber on the current * thread. This can be called to "kick off" execution of a fiber after it has * been created, in hopes that the effect can be executed synchronously. * * This is not the normal way of starting a fiber, but it is us

(effect: Effect.Effect<A, E, R>)

   * express goal of executing the fiber is to synchronously produce its exit.
   */
  start<R>(effect: Effect.Effect<A, E, R>): void {
    if (!this._running) {
      this._running = true
      const prev = (globalThis as any)[internalFiber.currentFiberURI]
      ;(globalThis as any)[internalFiber.currentFiberURI] = this
      try {
        this.evaluateEffect(effect)
      } finally {
        this._running = false
        ;(globalThis as any)[internalFiber.currentFiberURI] = prev
        // Because we're special casing `start`, we have to be responsible
        // for spinning up the fiber if there were new messages added to
        // the queue between the completion of the effect and the transition
        // to the not running state.
        if (this._queue.length > 0) {
          this.drainQueueLaterOnExecutor()
        }
      }
    } else {
      this.tell(FiberMessage.resume(effect))
    }
  }

  /**
   * Begins execution of the effect associated with this fiber on in the