scheduler.rb in async-2.4.1

- old
+ new

@@ -48,13 +48,16 @@
 			Kernel::raise "Closing scheduler with blocked operations!" if @blocked > 0
 			
 			# We depend on GVL for consistency:
 			# @guard.synchronize do
 			
-			@selector&.close
+			# We want `@selector = nil` to be a visible side effect from this point forward, specifically in `#interrupt` and `#unblock`. If the selector is closed, then we don't want to push any fibers to it.
+			selector = @selector
 			@selector = nil
 			
+			selector&.close
+			
 			# end
 			
 			consume
 		end
 		
@@ -67,13 +70,14 @@
 		def to_s
 			"\#<#{self.description} #{@children&.size || 0} children (#{stopped? ? 'stopped' : 'running'})>"
 		end
 		
 		# Interrupt the event loop and cause it to exit.
+		# @asynchronous May be called from any thread.
 		def interrupt
 			@interrupted = true
-			@selector.wakeup
+			@selector&.wakeup
 		end
 		
 		# Transfer from the calling fiber to the event loop.
 		def transfer
 			@selector.transfer
@@ -125,11 +129,13 @@
 		# @asynchronous May be called from any thread.
 		def unblock(blocker, fiber)
 			# $stderr.puts "unblock(#{blocker}, #{fiber})"
 			
 			# This operation is protected by the GVL:
-			@selector.push(fiber)
-			@selector.wakeup
+			if selector = @selector
+				selector.push(fiber)
+				selector.wakeup
+			end
 		end
 		
 		# @asynchronous May be non-blocking..
 		def kernel_sleep(duration = nil)
 			if duration