Code formatting.

Author: ioquatix

fixtures/async/chainable_async.rb

@@ -9,7 +9,7 @@ module Async
 		let(:chainable) {subject.new(parent: parent)}
 
 		it "should chain async to parent" do
-			expect(parent).to receive(:async).and_return {|*arguments, **options, &block|
+			expect(parent).to receive(:async).and_return{|*arguments, **options, &block|
 				Async(*arguments, **options, &block)
 			}
 

lib/async/barrier.rb

@@ -18,7 +18,7 @@ class Barrier
 		def initialize(parent: nil)
 			@tasks = List.new
 			@finished = Queue.new
-			@cond = Condition.new
+			@condition = Condition.new
 
 			@parent = parent
 		end
@@ -43,26 +43,32 @@ def size
 
 		# Execute a child task and add it to the barrier.
 		# @asynchronous Executes the given block concurrently.
+		# @returns [Task] The task which was created to execute the block.
 		def async(*arguments, parent: (@parent or Task.current), **options, &block)
 			raise "Barrier is stopped!" if @finished.closed?
 
 			waiting = nil
 
 			task = parent.async(*arguments, **options) do |task, *arguments|
+				# Create a new list node for the task and add it to the list of waiting tasks:
 				node = TaskNode.new(task)
 				@tasks.append(node)
-
+				
+				# Signal the outer async block that we have added the task to the list of waiting tasks, and that it can now wait for it to finish:
 				waiting = node
-				@cond.signal
-
+				@condition.signal
+				
+				# Invoke the block, which may raise an error. If it does, we will still signal that the task has finished:
 				block.call(task, *arguments)
 			ensure
+				# Signal that the task has finished, which will unblock the waiting task:
 				@finished.signal(node) unless @finished.closed?
 			end
-
-			@cond.wait while waiting.nil?
-
-			task
+			
+			# `parent.async` may yield before the child block executes, so we wait here until the child has appended itself to `@tasks`, ensuring `wait` cannot return early and miss tracking it:
+			@condition.wait while waiting.nil?
+			
+			return task
 		end
 
 		# Whether there are any tasks being held by the barrier.

test/async/barrier.rb

@@ -133,7 +133,7 @@
 				barrier.stop
 			end
 		end
-
+		
 		it "waits even if the child task yields immediately" do
 			class Yielder
 				def async(*arguments, **options, &block)
@@ -143,15 +143,15 @@ def async(*arguments, **options, &block)
 					end
 				end
 			end
-
+			
 			parent = Yielder.new
-
+			
 			3.times do |i|
-				barrier.async(parent:) {i}
+				barrier.async(parent:){i}
 			end
-
+			
 			expect(barrier.size).to be == 3
-
+			
 			results = []
 			barrier.wait do |task|
 				results << task.wait