Internalize libs/sync. (#7450)

Inline the one usage of this library, and remove the lib.

libs/sync/atomic_bool.go

@@ -1,33 +0,0 @@
-package sync
-
-import "sync/atomic"
-
-// AtomicBool is an atomic Boolean.
-// Its methods are all atomic, thus safe to be called by multiple goroutines simultaneously.
-// Note: When embedding into a struct one should always use *AtomicBool to avoid copy.
-// it's a simple implmentation from https://github.com/tevino/abool
-type AtomicBool int32
-
-// NewBool creates an AtomicBool with given default value.
-func NewBool(ok bool) *AtomicBool {
-	ab := new(AtomicBool)
-	if ok {
-		ab.Set()
-	}
-	return ab
-}
-
-// Set sets the Boolean to true.
-func (ab *AtomicBool) Set() {
-	atomic.StoreInt32((*int32)(ab), 1)
-}
-
-// UnSet sets the Boolean to false.
-func (ab *AtomicBool) UnSet() {
-	atomic.StoreInt32((*int32)(ab), 0)
-}
-
-// IsSet returns whether the Boolean is true.
-func (ab *AtomicBool) IsSet() bool {
-	return atomic.LoadInt32((*int32)(ab))&1 == 1
-}

libs/sync/atomic_bool_test.go

@@ -1,27 +0,0 @@
-package sync
-
-import (
-	"testing"
-
-	"github.com/stretchr/testify/assert"
-)
-
-func TestDefaultValue(t *testing.T) {
-	t.Parallel()
-	v := NewBool(false)
-	assert.False(t, v.IsSet())
-
-	v = NewBool(true)
-	assert.True(t, v.IsSet())
-}
-
-func TestSetUnSet(t *testing.T) {
-	t.Parallel()
-	v := NewBool(false)
-
-	v.Set()
-	assert.True(t, v.IsSet())
-
-	v.UnSet()
-	assert.False(t, v.IsSet())
-}