HeadFetcher data race fix (#3460)

* HeadFetcher data race fix

* bazel run //:gazelle -- fix

* add the db teardown to test

* add TestChainService_SaveHead_DataRace test

* split race and norace tests

* change testset name

* test CI with 'spectest' tag instead of 'raceon'

* one more test CI with 'spectest' tag instead of 'raceon'

* bazel run //:gazelle -- fix

* set test tag to 'race_on'

* not clone the state

beacon-chain/blockchain/chain_info_norace_test.go

@@ -0,0 +1,77 @@
+package blockchain
+
+import (
+	"context"
+	"testing"
+
+	testDB "github.com/prysmaticlabs/prysm/beacon-chain/db/testing"
+	ethpb "github.com/prysmaticlabs/prysm/proto/eth/v1alpha1"
+)
+
+func TestHeadSlot_DataRace(t *testing.T) {
+	db := testDB.SetupDB(t)
+	defer testDB.TeardownDB(t, db)
+	s := &Service{
+		beaconDB:       db,
+		canonicalRoots: make(map[uint64][]byte),
+	}
+	go func() {
+		s.saveHead(
+			context.Background(),
+			&ethpb.BeaconBlock{Slot: 777},
+			[32]byte{},
+		)
+	}()
+	s.HeadSlot()
+}
+
+func TestHeadRoot_DataRace(t *testing.T) {
+	db := testDB.SetupDB(t)
+	defer testDB.TeardownDB(t, db)
+	s := &Service{
+		beaconDB:       db,
+		canonicalRoots: make(map[uint64][]byte),
+	}
+	go func() {
+		s.saveHead(
+			context.Background(),
+			&ethpb.BeaconBlock{Slot: 777},
+			[32]byte{},
+		)
+	}()
+	s.HeadRoot()
+}
+
+func TestHeadBlock_DataRace(t *testing.T) {
+	db := testDB.SetupDB(t)
+	defer testDB.TeardownDB(t, db)
+	s := &Service{
+		beaconDB:       db,
+		canonicalRoots: make(map[uint64][]byte),
+	}
+	go func() {
+		s.saveHead(
+			context.Background(),
+			&ethpb.BeaconBlock{Slot: 777},
+			[32]byte{},
+		)
+	}()
+	s.HeadBlock()
+}
+
+func TestHeadState_DataRace(t *testing.T) {
+	db := testDB.SetupDB(t)
+	defer testDB.TeardownDB(t, db)
+	s := &Service{
+		beaconDB:       db,
+		canonicalRoots: make(map[uint64][]byte),
+	}
+	go func() {
+		s.saveHead(
+			context.Background(),
+			&ethpb.BeaconBlock{Slot: 777},
+			[32]byte{},
+		)
+	}()
+	s.HeadState()
+}