Fix multiple stops during child_exit hook.

Author: samuel-williams-shopify

async-service.gemspec

@@ -27,6 +27,6 @@ Gem::Specification.new do |spec|
 	spec.required_ruby_version = ">= 3.2"
 
 	spec.add_dependency "async"
-	spec.add_dependency "async-container", "~> 0.33"
+	spec.add_dependency "async-container", "~> 0.34"
 	spec.add_dependency "string-format", "~> 0.2"
 end

lib/async/service/policy.rb

@@ -51,8 +51,8 @@ def child_exit(container, child, status, name:, key:, **options)
 					rate = container.statistics.failure_rate.per_second
 
 					if rate > @failure_rate_threshold
-						# Only stop if container is still running (avoid redundant stop calls during shutdown)
-						if container.running?
+						# Only stop if container is not already stopping
+						unless container.stopping?
 							Console.error(self, "Failure rate exceeded threshold, stopping container!",
 								rate: rate,
 								threshold: @failure_rate_threshold

releases.md

@@ -1,5 +1,9 @@
 # Releases
 
+## Unreleased
+
+  - Use `container.stopping?` in policy to prevent redundant stop calls during graceful shutdown.
+
 ## v0.20.0
 
   - Introduce `Async::Service::Policy` for monitoring service health and implementing failure handling strategies. Default threshold: 6 failures in 60 seconds (0.1 failures/second).

test/async/service/policy.rb

@@ -30,8 +30,8 @@ def initialize
 					@statistics = Async::Container::Statistics.new(window: 10)
 				end
 
-				def running?
-					!@stopped
+				def stopping?
+					@stopped
 				end
 
 				def stop(graceful)
@@ -60,12 +60,12 @@ def success?
 			# 6 failures in same second = 0.6/sec which exceeds 5/10sec = 0.5/sec
 			rate = mock_container.statistics.failure_rate.per_second
 			expect(rate).to be > 0.5
-			expect(mock_container.stopped).to be == false
+			expect(mock_container).not.to be(:stopped)
 
 			# Trigger policy check
 			policy.child_exit(mock_container, nil, mock_status, name: "test", key: nil)
 
-			expect(mock_container.stopped).to be == true
+			expect(mock_container).to be(:stopped)
 		end
 
 		it "does not stop container when failure rate is acceptable" do
@@ -84,7 +84,7 @@ def success?
 			# Trigger policy check
 			policy.child_exit(mock_container, nil, mock_status, name: "test", key: nil)
 
-			expect(mock_container.stopped).to be == false
+			expect(mock_container).not.to be(:stopped)
 		end
 
 		it "does nothing on successful exit" do
@@ -96,7 +96,7 @@ def success_status.success?; true; end
 			# Even with low threshold, success shouldn't trigger stop
 			policy.child_exit(mock_container, nil, success_status, name: "test", key: nil)
 
-			expect(mock_container.stopped).to be == false
+			expect(mock_container).not.to be(:stopped)
 		end
 
 		it "does not stop container if already stopping" do
@@ -109,14 +109,14 @@ def success_status.success?; true; end
 
 			# Manually stop the container first
 			mock_container.stop(true)
-			expect(mock_container.stopped).to be == true
-			expect(mock_container.running?).to be == false
+			expect(mock_container).to be(:stopped)
+			expect(mock_container).to be(:stopping?)
 
 			# Policy should not call stop again
 			policy.child_exit(mock_container, nil, mock_status, name: "test", key: nil)
 
-			# Container is still stopped (no error from redundant stop call)
-			expect(mock_container.stopped).to be == true
+			# Container is still stopped (no redundant stop call)
+			expect(mock_container).to be(:stopped)
 		end
 	end