fix: fix deadlock issue when creating child actor (#383)

actors/pid.go

@@ -549,8 +549,7 @@ func (x *pid) SpawnChild(ctx context.Context, name string, actor Actor) (PID, er
 		return cid, nil
 	}
 
-	x.rwLocker.Lock()
-	defer x.rwLocker.Unlock()
+	x.rwLocker.RLock()
 
 	// create the child actor options child inherit parent's options
 	opts := []pidOption{
@@ -585,16 +584,20 @@ func (x *pid) SpawnChild(ctx context.Context, name string, actor Actor) (PID, er
 	if err != nil {
 		span.SetStatus(codes.Error, "SpawnChild")
 		span.RecordError(err)
+		x.rwLocker.RUnlock()
 		return nil, err
 	}
 
 	x.children.set(cid)
-	x.Watch(cid)
+	eventsStream := x.eventsStream
 
+	x.rwLocker.RUnlock()
 	span.SetStatus(codes.Ok, "SpawnChild")
 
-	if x.eventsStream != nil {
-		x.eventsStream.Publish(eventsTopic, &goaktpb.ActorChildCreated{
+	x.Watch(cid)
+
+	if eventsStream != nil {
+		eventsStream.Publish(eventsTopic, &goaktpb.ActorChildCreated{
 			Address:   cid.ActorPath().RemoteAddress(),
 			CreatedAt: timestamppb.Now(),
 			Parent:    x.ActorPath().RemoteAddress(),

actors/pid_test.go

@@ -42,6 +42,7 @@ import (
 	"google.golang.org/protobuf/proto"
 
 	"github.com/tochemey/goakt/v2/goaktpb"
+	"github.com/tochemey/goakt/v2/internal/eventstream"
 	"github.com/tochemey/goakt/v2/log"
 	"github.com/tochemey/goakt/v2/telemetry"
 	"github.com/tochemey/goakt/v2/test/data/testpb"
@@ -1024,6 +1025,58 @@ func TestSpawnChild(t *testing.T) {
 		err = parent.Shutdown(ctx)
 		assert.NoError(t, err)
 	})
+	t.Run("With child created event published", func(t *testing.T) {
+		// create a test context
+		ctx := context.TODO()
+		// create the actor path
+		actorPath := NewPath("Parent", NewAddress("sys", "host", 1))
+
+		eventsStream := eventstream.New()
+
+		// add a subscriber
+		subsriber := eventsStream.AddSubscriber()
+		eventsStream.Subscribe(subsriber, eventsTopic)
+
+		// create the parent actor
+		parent, err := newPID(ctx, actorPath,
+			newSupervisor(),
+			withInitMaxRetries(1),
+			withCustomLogger(log.DiscardLogger),
+			withEventsStream(eventsStream),
+			withAskTimeout(replyTimeout))
+
+		require.NoError(t, err)
+		assert.NotNil(t, parent)
+
+		// create the child actor
+		child, err := parent.SpawnChild(ctx, "SpawnChild", newSupervised())
+		assert.NoError(t, err)
+		assert.NotNil(t, child)
+
+		assert.Len(t, parent.Children(), 1)
+
+		time.Sleep(time.Second)
+
+		var events []*goaktpb.ActorChildCreated
+		for message := range subsriber.Iterator() {
+			// get the event payload
+			payload := message.Payload()
+			switch msg := payload.(type) {
+			case *goaktpb.ActorChildCreated:
+				events = append(events, msg)
+			}
+		}
+
+		require.NotEmpty(t, events)
+		require.Len(t, events, 1)
+
+		event := events[0]
+		assert.True(t, proto.Equal(parent.ActorPath().RemoteAddress(), event.GetParent()))
+
+		//stop the actor
+		err = parent.Shutdown(ctx)
+		assert.NoError(t, err)
+	})
 }
 func TestPoisonPill(t *testing.T) {
 	ctx := context.TODO()