fix: #1214 - go race detect (#1220)

* fix: #1214 - go race detect

* add license header

* add comment to track issue

* remove dup return

* add a benchmark test for JoinIfNotEqual

* revise benchmark test

cluster/router/utils/bitmap_util.go

@@ -28,10 +28,16 @@ import (
 var EmptyAddr = roaring.NewBitmap()
 
 func JoinIfNotEqual(left *roaring.Bitmap, right *roaring.Bitmap) *roaring.Bitmap {
-	if !left.Equals(right) {
-		left = left.Clone()
-		left.And(right)
-	}
+	// FIXME: cannot use left.Equals(right) as a shortcut because roaring bitmap has a race issue in its equals impl.
+	// see issue: https://github.com/RoaringBitmap/roaring/issues/305
+	/*
+		if !left.Equals(right) {
+			left = left.Clone()
+			left.And(right)
+		}
+	*/
+	left = left.Clone()
+	left.And(right)
 	return left
 }
 

cluster/router/utils/bitmap_util_test.go

@@ -0,0 +1,78 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements.  See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.
+ * The ASF licenses this file to You under the Apache License, Version 2.0
+ * (the "License"); you may not use this file except in compliance with
+ * the License.  You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package utils
+
+import (
+	"sync"
+	"testing"
+)
+
+import (
+	"github.com/RoaringBitmap/roaring"
+	"github.com/stretchr/testify/assert"
+)
+
+func TestJoinIfNotEqual(t *testing.T) {
+	l := roaring.NewBitmap()
+	l.Add(uint32(1))
+	l.Add(uint32(2))
+	l.Add(uint32(3))
+	r := roaring.NewBitmap()
+	r.AddRange(1, 4)
+
+	// this is for race condition test
+	var wg sync.WaitGroup
+	wg.Add(2)
+	go func() {
+		defer wg.Done()
+		JoinIfNotEqual(l, r)
+	}()
+
+	go func() {
+		defer wg.Done()
+		JoinIfNotEqual(l, r)
+	}()
+	wg.Wait()
+
+	assert.True(t, l.Equals(JoinIfNotEqual(l, r)))
+}
+
+func BenchmarkJoinIfNotEqual10(b *testing.B) {
+	benchmarkJoinIfNotEqual(b, 10)
+}
+
+func BenchmarkJoinIfNotEqual1000(b *testing.B) {
+	benchmarkJoinIfNotEqual(b, 1000)
+}
+
+func BenchmarkJoinIfNotEqual100000(b *testing.B) {
+	benchmarkJoinIfNotEqual(b, 100000)
+}
+
+func benchmarkJoinIfNotEqual(b *testing.B, size int) {
+	l := roaring.NewBitmap()
+	for i := 0; i < size; i++ {
+		l.Add(uint32(i))
+	}
+	r := roaring.NewBitmap()
+	r.AddRange(0, uint64(size+1))
+
+	for i := 0; i < b.N; i++ {
+		JoinIfNotEqual(l, r)
+	}
+}

go.mod

@@ -3,7 +3,7 @@ module github.com/apache/dubbo-go
 go 1.15
 
 require (
-	github.com/RoaringBitmap/roaring v0.5.5
+	github.com/RoaringBitmap/roaring v0.6.1
 	github.com/Workiva/go-datastructures v1.0.52
 	github.com/afex/hystrix-go v0.0.0-20180502004556-fa1af6a1f4f5
 	github.com/alibaba/sentinel-golang v1.0.2