add XXX to core.JsonData mutex

core/structs.go

@@ -110,6 +110,10 @@ func (f *Feed) Swap(i, j int) {
 	f.Items[i], f.Items[j] = f.Items[j], f.Items[i]
 }
 
+// XXX: do both feedsMu and pagesMu need to be (un)locked together or can they
+// be locked individually?  they are in the same struct but they're different
+// elements so they shuld be able to be accessed at the same time, right?
+
 // Lock locks both feed and page mutexes.
 func (j *jsonData) Lock() {
 	j.feedsMu.Lock()