connection: fix: reader go-routine is leaked on connection close

.github/workflows/tests.yml

@@ -20,9 +20,9 @@ jobs:
           - 5672:5672
     steps:
       - name: Check out code into the Go module directory
-        uses: actions/checkout@v2
+        uses: actions/checkout@v3
       - name: Set up Go environment
-        uses: actions/setup-go@v2
+        uses: actions/setup-go@v3
         with:
           go-version: ${{ matrix.go-version }}
       - name: Tests

Makefile

@@ -5,11 +5,9 @@ list: ## list Makefile targets
 	@echo "The most used targets: \n"
 	@grep -E '^[a-zA-Z_-]+:.*?## .*$$' $(MAKEFILE_LIST) | sort | awk 'BEGIN {FS = ":.*?## "}; {printf "\033[36m%-20s\033[0m %s\n", $$1, $$2}'
 
-
 fmt: ## Run go fmt against code
 	go fmt ./...
 
-
 vet: ## Run go vet against code
 	go vet ./...
 

connection.go

@@ -539,6 +539,8 @@ func (c *Connection) reader(r io.Reader) {
 	frames := &reader{buf}
 	conn, haveDeadliner := r.(readDeadliner)
 
+	defer close(c.rpc)
+
 	for {
 		frame, err := frames.ReadFrame()
 
@@ -689,27 +691,26 @@ func (c *Connection) call(req message, res ...message) error {
 		}
 	}
 
-	select {
-	case err, ok := <-c.errors:
-		if !ok {
+	msg, ok := <-c.rpc
+	if !ok {
+		err, errorsChanIsOpen := <-c.errors
+		if !errorsChanIsOpen {
 			return ErrClosed
 		}
 		return err
+	}
 
-	case msg := <-c.rpc:
-		// Try to match one of the result types
-		for _, try := range res {
-			if reflect.TypeOf(msg) == reflect.TypeOf(try) {
-				// *res = *msg
-				vres := reflect.ValueOf(try).Elem()
-				vmsg := reflect.ValueOf(msg).Elem()
-				vres.Set(vmsg)
-				return nil
-			}
+	// Try to match one of the result types
+	for _, try := range res {
+		if reflect.TypeOf(msg) == reflect.TypeOf(try) {
+			// *res = *msg
+			vres := reflect.ValueOf(try).Elem()
+			vmsg := reflect.ValueOf(msg).Elem()
+			vres.Set(vmsg)
+			return nil
 		}
-		return ErrCommandInvalid
 	}
-	// unreachable
+	return ErrCommandInvalid
 }
 
 //    Connection          = open-Connection *use-Connection close-Connection

connection_test.go

@@ -213,3 +213,31 @@ func TestChannelIsClosed(t *testing.T) {
 		t.Fatal("channel expected to be marked as closed")
 	}
 }
+
+// TestReaderGoRoutineTerminatesWhenMsgIsProcessedDuringClose tests the issue
+// described in https://github.com/rabbitmq/amqp091-go/issues/69.
+func TestReaderGoRoutineTerminatesWhenMsgIsProcessedDuringClose(t *testing.T) {
+	const routines = 10
+	c := integrationConnection(t, t.Name())
+
+	var wg sync.WaitGroup
+	startSigCh := make(chan interface{})
+
+	for i := 0; i < routines; i++ {
+		wg.Add(1)
+		go func(id int) {
+			defer wg.Done()
+
+			<-startSigCh
+
+			err := c.Close()
+			if err != nil {
+				t.Logf("close failed in routine %d: %s", id, err.Error())
+			}
+		}(i)
+	}
+	close(startSigCh)
+
+	t.Log("waiting for go-routines to terminate")
+	wg.Wait()
+}

reconnect_test.go

@@ -56,11 +56,12 @@ func ExampleConnection_reconnect() {
 		// between reconnects, shares the same topology as the consumer.  If we rather
 		// sent all messages up front, the first consumer would receive every message.
 		// We would rather show how the messages are not lost between reconnects.
-		_, pub, err := setup(url, queue)
+		con, pub, err := setup(url, queue)
 		if err != nil {
 			fmt.Println("err publisher setup:", err)
 			return
 		}
+		defer con.Close()
 
 		// Purge the queue from the publisher side to establish initial state
 		if _, err := pub.QueuePurge(queue, false); err != nil {