refactor

vendor/github.com/jesseduffield/gocui/tcell_driver.go

@@ -5,6 +5,8 @@
 package gocui
 
 import (
+	"sync"
+
 	"github.com/gdamore/tcell/v2"
 )
 
@@ -21,6 +23,7 @@ type oldStyle struct {
 // we're using this cache to speed up rendering, because obtaining the tcell style
 // from the old style is deterministic
 var cellStyleCache map[oldStyle]tcell.Style = map[oldStyle]tcell.Style{}
+var cacheMutex = sync.RWMutex{}
 
 // tcellInit initializes tcell screen for use.
 func tcellInit() error {
@@ -43,7 +46,10 @@ func tcellSetCell(x, y int, ch rune, fg, bg Attribute, outputMode OutputMode) {
 
 // getTcellStyle creates tcell.Style from Attributes
 func getTcellStyle(input oldStyle) tcell.Style {
-	if cachedResult, ok := cellStyleCache[input]; ok {
+	cacheMutex.RLock()
+	cachedResult, ok := cellStyleCache[input]
+	cacheMutex.RUnlock()
+	if ok {
 		return cachedResult
 	}
 
@@ -59,7 +65,9 @@ func getTcellStyle(input oldStyle) tcell.Style {
 		st = setTcellFontEffectStyle(st, input.bg)
 	}
 
+	cacheMutex.Lock()
 	cellStyleCache[input] = st
+	cacheMutex.Unlock()
 
 	return st
 }