Fix a runtime deadlock as well as fixing some graceful exiting issues (#945)

runtime/default.go

@@ -98,31 +98,39 @@ func (r *runtime) run(events <-chan Event) {
 				}
 				buildTime := time.Unix(updateTimeStamp, 0)
 				processEvent := func(event Event, service *Service) error {
-					buildTimeStamp, err := strconv.ParseInt(service.Version, 10, 64)
+					r.RLock()
+					name := service.Name
+					version := service.Version
+					r.RUnlock()
+
+					buildTimeStamp, err := strconv.ParseInt(version, 10, 64)
 					if err != nil {
 						return err
 					}
 					muBuild := time.Unix(buildTimeStamp, 0)
 					if buildTime.After(muBuild) {
+						log.Debugf("Runtime updating service %s", name)
 						if err := r.Update(service); err != nil {
 							return err
 						}
+						r.Lock()
 						service.Version = fmt.Sprintf("%d", buildTime.Unix())
+						r.Unlock()
 					}
 					return nil
 				}
-				r.Lock()
+
 				if len(event.Service) > 0 {
+					r.RLock()
 					service, ok := r.services[event.Service]
+					r.RUnlock()
 					if !ok {
 						log.Debugf("Runtime unknown service: %s", event.Service)
-						r.Unlock()
 						continue
 					}
 					if err := processEvent(event, service.Service); err != nil {
 						log.Debugf("Runtime error updating service %s: %v", event.Service, err)
 					}
-					r.Unlock()
 					continue
 				}
 				// if blank service was received we update all services
@@ -131,7 +139,6 @@ func (r *runtime) run(events <-chan Event) {
 						log.Debugf("Runtime error updating service %s: %v", service.Name, err)
 					}
 				}
-				r.Unlock()
 			}
 		case <-r.closed:
 			log.Debugf("Runtime stopped.")
@@ -162,6 +169,7 @@ func (r *runtime) Create(s *Service, opts ...CreateOption) error {
 	r.services[s.Name] = newService(s, options)
 
 	// push into start queue
+	log.Debugf("Runtime creating service %s", s.Name)
 	r.start <- r.services[s.Name]
 
 	return nil
@@ -172,9 +180,20 @@ func (r *runtime) Delete(s *Service) error {
 	r.Lock()
 	defer r.Unlock()
 
+	log.Debugf("Runtime deleting service %s", s.Name)
 	if s, ok := r.services[s.Name]; ok {
+		// check if running
+		if !s.Running() {
+			delete(r.services, s.Name)
+			return nil
+		}
+		// otherwise stop it
+		if err := s.Stop(); err != nil {
+			return err
+		}
+		// delete it
 		delete(r.services, s.Name)
-		return s.Stop()
+		return nil
 	}
 
 	return nil
@@ -182,13 +201,22 @@ func (r *runtime) Delete(s *Service) error {
 
 // Update attemps to update the service
 func (r *runtime) Update(s *Service) error {
+	var opts []CreateOption
+
+	// check if the service already exists
+	r.RLock()
+	if service, ok := r.services[s.Name]; ok {
+		opts = append(opts, WithOutput(service.output))
+	}
+	r.RUnlock()
+
 	// delete the service
 	if err := r.Delete(s); err != nil {
 		return err
 	}
 
 	// create new service
-	return r.Create(s)
+	return r.Create(s, opts...)
 }
 
 // List returns a slice of all services tracked by the runtime

runtime/process/os/os.go

@@ -6,6 +6,7 @@ import (
 	"os"
 	"os/exec"
 	"strconv"
+	"syscall"
 
 	"github.com/micro/go-micro/runtime/process"
 )
@@ -24,6 +25,9 @@ func (p *Process) Fork(exe *process.Executable) (*process.PID, error) {
 	// set env vars
 	cmd.Env = append(cmd.Env, exe.Env...)
 
+	// create process group
+	cmd.SysProcAttr = &syscall.SysProcAttr{Setpgid: true}
+
 	in, err := cmd.StdinPipe()
 	if err != nil {
 		return nil, err
@@ -61,7 +65,16 @@ func (p *Process) Kill(pid *process.PID) error {
 		return err
 	}
 
-	return pr.Kill()
+	// now kill it
+	err = pr.Kill()
+
+	// kill the group
+	if pgid, err := syscall.Getpgid(id); err == nil {
+		syscall.Kill(-pgid, syscall.SIGKILL)
+	}
+
+	// return the kill error
+	return err
 }
 
 func (p *Process) Wait(pid *process.PID) error {

runtime/service.go

@@ -129,7 +129,12 @@ func (s *service) Stop() error {
 		if s.PID == nil {
 			return nil
 		}
-		return s.Process.Kill(s.PID)
+		// kill the process
+		err := s.Process.Kill(s.PID)
+		// wait for it to exit
+		s.Process.Wait(s.PID)
+		// return the kill error
+		return err
 	}
 }