Re-introduce terminate.

lib/async/scheduler.rb

@@ -75,30 +75,33 @@ def load
 		# Invoked when the fiber scheduler is being closed.
 		#
 		# Executes the run loop until all tasks are finished, then closes the scheduler.
-		def scheduler_close
+		def scheduler_close(error = $!)
 			# If the execution context (thread) was handling an exception, we want to exit as quickly as possible:
-			unless $!
+			unless error
 				self.run
 			end
 		ensure
 			self.close
 		end
 
-		private def shutdown!
-			# It's critical to stop all tasks. Otherwise they might be holding on to resources which are never closed/released correctly.
-			self.stop
-
-			self.run_loop do
-				unless @children.nil?
-					run_once!
-				end
+		# Terminate all child tasks.
+		def terminate
+			# If that doesn't work, take more serious action:
+			@children&.each do |child|
+				child.terminate
 			end
+
+			return @children.nil?
 		end
 
 		# Terminate all child tasks and close the scheduler.
 		# @public Since `stable-v1`.
 		def close
-			self.shutdown!
+			self.run_loop do
+				until self.terminate
+					self.run_once!
+				end
+			end
 
 			Kernel.raise "Closing scheduler with blocked operations!" if @blocked > 0
 		ensure
@@ -288,21 +291,6 @@ def process_wait(pid, flags)
 			return @selector.process_wait(Fiber.current, pid, flags)
 		end
 
-		# Run one iteration of the event loop.
-		# Does not handle interrupts.
-		# @parameter timeout [Float | Nil] The maximum timeout, or if nil, indefinite.
-		# @returns [Boolean] Whether there is more work to do.
-		def run_once(timeout = nil)
-			Kernel.raise "Running scheduler on non-blocking fiber!" unless Fiber.blocking?
-
-			# If we are finished, we stop the task tree and exit:
-			if @children.nil?
-				return false
-			end
-
-			return run_once!(timeout)
-		end
-
 		# Run one iteration of the event loop.
 		#
 		# When terminating the event loop, we already know we are finished. So we don't need to check the task tree. This is a logical requirement because `run_once` ignores transient tasks. For example, a single top level transient task is not enough to keep the reactor running, but during termination we must still process it in order to terminate child tasks.
@@ -346,6 +334,25 @@ def run_once(timeout = nil)
 			return true
 		end
 
+		# Run one iteration of the event loop.
+		# Does not handle interrupts.
+		# @parameter timeout [Float | Nil] The maximum timeout, or if nil, indefinite.
+		# @returns [Boolean] Whether there is more work to do.
+		def run_once(timeout = nil)
+			Kernel.raise "Running scheduler on non-blocking fiber!" unless Fiber.blocking?
+
+			if self.finished?
+				self.stop
+			end
+
+			# If we are finished, we stop the task tree and exit:
+			if @children.nil?
+				return false
+			end
+
+			return run_once!(timeout)
+		end
+
 		# Checks and clears the interrupted state of the scheduler.
 		# @returns [Boolean] Whether the reactor has been interrupted.
 		private def interrupted?
@@ -363,10 +370,8 @@ def run_once(timeout = nil)
 
 		# Stop all children, including transient children, ignoring any signals.
 		def stop
-			Thread.handle_interrupt(::SignalException => :never) do
-				@children&.each do |child|
-					child.stop
-				end
+			@children&.each do |child|
+				child.stop
 			end
 		end
 
@@ -382,7 +387,9 @@ def stop
 					end
 				end
 			rescue Interrupt => interrupt
-				self.stop
+				Thread.handle_interrupt(::SignalException => :never) do
+					self.stop
+				end
 
 				retry
 			end
@@ -398,11 +405,7 @@ def run(...)
 			initial_task = self.async(...) if block_given?
 
 			self.run_loop do
-				if self.finished?
-					self.stop
-				end
-
-				run_once!
+				run_once
 			end
 
 			return initial_task