3 files changed, 7 insertions, 23 deletions
diff --git a/lib/msgstore.go b/lib/msgstore.go
index fbffa0a..827d7cb 100644
--- a/lib/msgstore.go
+++ b/lib/msgstore.go
@@ -2,7 +2,6 @@ package lib
 
 import (
 	"io"
-	"sync"
 	"time"
 
 	"github.com/emersion/go-imap"
@@ -12,8 +11,6 @@ import (
 
 // Accesses to fields must be guarded by MessageStore.Lock/Unlock
 type MessageStore struct {
-	sync.Mutex
-
 	Deleted  map[uint32]interface{}
 	DirInfo  types.DirectoryInfo
 	Messages map[uint32]*types.MessageInfo
@@ -49,9 +46,6 @@ func NewMessageStore(worker *types.Worker,
 func (store *MessageStore) FetchHeaders(uids []uint32,
 	cb func(*types.MessageInfo)) {
 
-	store.Lock()
-	defer store.Unlock()
-
 	// TODO: this could be optimized by pre-allocating toFetch and trimming it
 	// at the end. In practice we expect to get most messages back in one frame.
 	var toFetch imap.SeqSet
@@ -74,9 +68,6 @@ func (store *MessageStore) FetchHeaders(uids []uint32,
 }
 
 func (store *MessageStore) FetchFull(uids []uint32, cb func(io.Reader)) {
-	store.Lock()
-	defer store.Unlock()
-
 	// TODO: this could be optimized by pre-allocating toFetch and trimming it
 	// at the end. In practice we expect to get most messages back in one frame.
 	var toFetch imap.SeqSet
@@ -134,8 +125,6 @@ func merge(to *types.MessageInfo, from *types.MessageInfo) {
 }
 
 func (store *MessageStore) Update(msg types.WorkerMessage) {
-	store.Lock()
-
 	update := false
 	switch msg := msg.(type) {
 	case *types.DirectoryInfo:
@@ -201,8 +190,6 @@ func (store *MessageStore) Update(msg types.WorkerMessage) {
 		update = true
 	}
 
-	store.Unlock()
-
 	if update {
 		store.update()
 	}
@@ -220,7 +207,6 @@ func (store *MessageStore) update() {
 
 func (store *MessageStore) Delete(uids []uint32,
 	cb func(msg types.WorkerMessage)) {
-	store.Lock()
 
 	var set imap.SeqSet
 	for _, uid := range uids {
@@ -228,8 +214,6 @@ func (store *MessageStore) Delete(uids []uint32,
 		store.Deleted[uid] = nil
 	}
 
-	store.Unlock()
-
 	store.worker.PostAction(&types.DeleteMessages{Uids: set}, cb)
 	store.update()
 }
@@ -249,7 +233,6 @@ func (store *MessageStore) Copy(uids []uint32, dest string,
 
 func (store *MessageStore) Move(uids []uint32, dest string,
 	cb func(msg types.WorkerMessage)) {
-	store.Lock()
 
 	var set imap.SeqSet
 	for _, uid := range uids {
@@ -257,8 +240,6 @@ func (store *MessageStore) Move(uids []uint32, dest string,
 		store.Deleted[uid] = nil
 	}
 
-	store.Unlock()
-
 	store.worker.PostAction(&types.CopyMessages{
 		Destination: dest,
 		Uids:        set,
diff --git a/lib/ui/interfaces.go b/lib/ui/interfaces.go
index d27afe2..0cdffc1 100644
--- a/lib/ui/interfaces.go
+++ b/lib/ui/interfaces.go
@@ -4,12 +4,15 @@ import (
 	"github.com/gdamore/tcell"
 )
 
+// Drawable is a UI component that can draw. Unless specified, all methods must
+// only be called from a single goroutine, the UI goroutine.
 type Drawable interface {
-	// Called when this renderable should draw itself
+	// Called when this renderable should draw itself.
 	Draw(ctx *Context)
-	// Specifies a function to call when this cell needs to be redrawn
+	// Specifies a function to call when this cell needs to be redrawn. The
+	// callback may be called in any goroutine.
 	OnInvalidate(callback func(d Drawable))
-	// Invalidates the drawable
+	// Invalidates the drawable. This can be called from any goroutine.
 	Invalidate()
 }
 
diff --git a/lib/ui/ui.go b/lib/ui/ui.go
index 9d9a5da..91a26da 100644
--- a/lib/ui/ui.go
+++ b/lib/ui/ui.go
@@ -10,7 +10,7 @@ import (
 
 type UI struct {
 	Content DrawableInteractive
-	exit    atomic.Value
+	exit    atomic.Value // bool
 	ctx     *Context
 	screen  tcell.Screen