Fix race condition in Application and FasthttpService

Author: felipemfp

application.go

@@ -16,9 +16,9 @@ type ApplicationConfig struct {
 }
 
 type Application struct {
+	serviceState
 	fasthttpService FasthttpService
 	Configuration   ApplicationConfig
-	running         bool
 	done            chan bool
 	signals         chan os.Signal
 }
@@ -33,6 +33,8 @@ func NewApplication(config ApplicationConfig, router Router) *Application {
 	}
 
 	app.fasthttpService.Server.Handler = router.Handler()
+	app.done = make(chan bool, 1)
+	app.signals = make(chan os.Signal, 1)
 
 	return app
 }
@@ -57,17 +59,14 @@ func (app *Application) Start() error {
 		return err
 	}
 
-	app.done = make(chan bool, 1)
-	app.signals = make(chan os.Signal, 1)
-
 	go func() {
 		signal.Notify(app.signals, syscall.SIGINT, syscall.SIGTERM)
 		if _, ok := <-app.signals; ok {
 			app.Stop()
 		}
 	}()
 
-	app.running = true
+	app.setRunning(true)
 	if err := app.fasthttpService.Start(); err != nil {
 		return err
 	}
@@ -77,14 +76,14 @@ func (app *Application) Start() error {
 }
 
 func (app *Application) Stop() error {
-	if app.running {
+	if app.isRunning() {
 		defer func() {
 			if app.Configuration.ServiceStarter != nil {
 				app.Configuration.ServiceStarter.Stop(true)
 			}
-			close(app.signals)
-			close(app.done)
-			app.running = false
+			signal.Stop(app.signals)
+			app.done <- true
+			app.setRunning(false)
 		}()
 		return app.fasthttpService.Stop()
 	}

fasthttp_service.go

@@ -23,7 +23,7 @@ type FasthttpServiceConfigurationTLS struct {
 
 // FasthttpService implements the server for starting
 type FasthttpService struct {
-	running       bool
+	serviceState
 	Configuration FasthttpServiceConfiguration
 	Server        fasthttp.Server
 }
@@ -50,19 +50,16 @@ func (service *FasthttpService) ApplyConfiguration(configuration interface{}) er
 
 // Restart returns an error due to fasthttp not being able to stop the service.
 func (service *FasthttpService) Restart() error {
-	if service.running {
-		err := service.Stop()
-		if err != nil {
-			return err
-		}
+	if err := service.Stop(); err != nil {
+		return err
 	}
 	return service.Start()
 }
 
 // Start ListenAndServe the server. This method is blocking because it uses
 // the fasthttp.ListenAndServe implementation.
 func (service *FasthttpService) Start() error {
-	service.running = true
+	service.setRunning(true)
 
 	if service.Configuration.TLS == nil {
 		return service.Server.ListenAndServe(service.Configuration.Bind)
@@ -73,9 +70,10 @@ func (service *FasthttpService) Start() error {
 
 // Stop closes the listener and waits the `Start` to stop.
 func (service *FasthttpService) Stop() error {
-	if service.running {
-		service.running = false
+	if service.isRunning() {
+		service.setRunning(false)
 		return service.Server.Shutdown()
 	}
+
 	return nil
 }

service_state.go

@@ -0,0 +1,20 @@
+package hermes
+
+import "sync"
+
+type serviceState struct {
+	sync.RWMutex
+	_running bool
+}
+
+func (service *serviceState) isRunning() bool {
+	service.RLock()
+	defer service.RUnlock()
+	return service._running
+}
+
+func (service *serviceState) setRunning(v bool) {
+	service.Lock()
+	service._running = v
+	service.Unlock()
+}