.

go/zodb/storage/demo/demo.go

@@ -33,6 +33,7 @@ import (
 
 	"lab.nexedi.com/kirr/go123/mem"
 	"lab.nexedi.com/kirr/go123/xerr"
+	"lab.nexedi.com/kirr/go123/xsync"
 	"lab.nexedi.com/kirr/neo/go/internal/task"
 	"lab.nexedi.com/kirr/neo/go/zodb"
 )
@@ -61,14 +62,27 @@ func (d *Storage) Close() (err error) {
 }
 
 // Sync implements zodb.IStorageDriver .
-func (d *Storage) Sync(ctx context.Context) (head zodb.Tid, err error) {
+func (d *Storage) Sync(ctx context.Context) (_ zodb.Tid, err error) {
 	defer func() {
 		if err != nil {
 			err = &zodb.OpError{URL: d.URL(), Op: "sync", Err: err}
 		}
 	}()
 
-	head, err = d.δ.Sync(ctx)
+	var head zodb.Tid
+	wg := xsync.NewWorkGroup(ctx)
+	wg.Go(func(ctx context.Context) error {
+		h, err := d.δ.Sync(ctx)
+		head = h
+		return err
+	})
+	wg.Go(func(ctx context.Context) error {
+		baseHead, err := d.base.Sync(ctx)
+		// XXX baseHead != .baseAt0 -> fail
+		return err
+	})
+
+	err = wg.Wait()
 	if err != nil {
 		return zodb.InvalidTid, err
 	}