replace util atomic function with standard sync/atomic operation in hotspot module (#266)

Author: luckyxiaoqiang

core/hotspot/concurrency_stat_slot.go

@@ -1,9 +1,10 @@
 package hotspot
 
 import (
+	"sync/atomic"
+
 	"github.com/alibaba/sentinel-golang/core/base"
 	"github.com/alibaba/sentinel-golang/logging"
-	"github.com/alibaba/sentinel-golang/util"
 )
 
 const (
@@ -39,7 +40,7 @@ func (c *ConcurrencyStatSlot) OnEntryPassed(ctx *base.EntryContext) {
 			}
 			continue
 		}
-		util.IncrementAndGetInt64(concurrencyPtr)
+		atomic.AddInt64(concurrencyPtr, 1)
 	}
 }
 
@@ -64,6 +65,6 @@ func (c *ConcurrencyStatSlot) OnCompleted(ctx *base.EntryContext) {
 			}
 			continue
 		}
-		util.DecrementAndGetInt64(concurrencyPtr)
+		atomic.AddInt64(concurrencyPtr, -1)
 	}
 }

util/atomic.go

@@ -2,34 +2,6 @@ package util
 
 import "sync/atomic"
 
-func IncrementAndGetInt64(v *int64) int64 {
-	if v == nil {
-		panic("Nil reference in util.IncrementAndGetInt64")
-	}
-	old := int64(0)
-	for {
-		old = atomic.LoadInt64(v)
-		if atomic.CompareAndSwapInt64(v, old, old+1) {
-			break
-		}
-	}
-	return old + 1
-}
-
-func DecrementAndGetInt64(v *int64) int64 {
-	if v == nil {
-		panic("Nil reference in util.DecrementAndGetInt64")
-	}
-	old := int64(0)
-	for {
-		old = atomic.LoadInt64(v)
-		if atomic.CompareAndSwapInt64(v, old, old-1) {
-			break
-		}
-	}
-	return old - 1
-}
-
 type AtomicBool struct {
 	// default 0, means false
 	flag int32

util/atomic_test.go

@@ -1,8 +1,6 @@
 package util
 
 import (
-	"fmt"
-	"sync"
 	"testing"
 
 	"github.com/stretchr/testify/assert"
@@ -24,17 +22,3 @@ func TestAtomicBool_GetAndSet(t *testing.T) {
 	b.Set(true)
 	assert.True(t, b.Get() == true, "the value is false, expect true.")
 }
-
-func TestIncrementAndGetInt64(t *testing.T) {
-	n := int64(0)
-	wg := &sync.WaitGroup{}
-	wg.Add(100)
-	for i := 0; i < 100; i++ {
-		go func(g *sync.WaitGroup) {
-			IncrementAndGetInt64(&n)
-			wg.Done()
-		}(wg)
-	}
-	wg.Wait()
-	assert.True(t, n == 100, fmt.Sprintf("current n is %d, expect 100.", n))
-}