Better support for Fiber.set_scheduler.

lib/async/reactor.rb

@@ -21,6 +21,10 @@ def initialize(...)
 			Fiber.set_scheduler(self)
 		end
 
+		def scheduler_close
+			self.close
+		end
+
 		public :sleep
 	end
 end

lib/async/scheduler.rb

@@ -34,6 +34,12 @@ def initialize(parent = nil, selector: nil)
 			@timers = ::Timers::Group.new
 		end
 
+		def scheduler_close
+			self.run
+		ensure
+			self.close
+		end
+
 		# @public Since `stable-v1`.
 		def close
 			# This is a critical step. Because tasks could be stored as instance variables, and since the reactor is (probably) going out of scope, we need to ensure they are stopped. Otherwise, the tasks will belong to a reactor that will never run again and are not stopped.

lib/kernel/async.rb

@@ -25,6 +25,7 @@ def Async(...)
 		if current = ::Async::Task.current?
 			return current.async(...)
 		else
+			# This calls Fiber.set_scheduler(self):
 			reactor = ::Async::Reactor.new
 
 			begin

lib/kernel/sync.rb

@@ -19,6 +19,7 @@ def Sync(&block)
 		if task = ::Async::Task.current?
 			yield task
 		else
+			# This calls Fiber.set_scheduler(self):
 			reactor = Async::Reactor.new
 
 			begin

test/fiber.rb

@@ -0,0 +1,30 @@
+# frozen_string_literal: true
+
+# Released under the MIT License.
+# Copyright, 2022, by Samuel Williams.
+
+require 'async/reactor'
+
+describe Fiber do
+	with '.schedule' do
+		it "can create several tasks" do
+			sequence = []
+
+			Thread.new do
+				scheduler = Async::Scheduler.new
+				Fiber.set_scheduler(scheduler)
+
+				Fiber.schedule do
+					3.times do |i|
+						Fiber.schedule do
+							sleep (i / 1000.0)
+							sequence << i
+						end
+					end
+				end
+			end.join
+
+			expect(sequence).to be == [0, 1, 2]
+		end
+	end
+end