arc cache is threadsafe

chain/badtscache.go

@@ -1,14 +1,11 @@
 package chain
 
 import (
-	"sync"
-
 	lru "github.com/hashicorp/golang-lru"
 	"github.com/ipfs/go-cid"
 )
 
 type BadBlockCache struct {
-	lk        sync.Mutex
 	badBlocks *lru.ARCCache
 }
 
@@ -24,13 +21,9 @@ func NewBadBlockCache() *BadBlockCache {
 }
 
 func (bts *BadBlockCache) Add(c cid.Cid) {
-	bts.lk.Lock()
-	defer bts.lk.Unlock()
 	bts.badBlocks.Add(c, nil)
 }
 
 func (bts *BadBlockCache) Has(c cid.Cid) bool {
-	bts.lk.Lock()
-	defer bts.lk.Unlock()
 	return bts.badBlocks.Contains(c)
 }