From 7b3c3de35e5c1c59a6f99d40137aba9a10e648ad Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?=E7=90=86=E5=B7=A5=E7=94=B7?= <15822775539@163.com>
Date: Wed, 3 Feb 2021 21:41:10 +0800
Subject: [PATCH] ring struct add lock (#434)

Co-authored-by: liuhuan210 <liuhuan210@jd.com>
---
 core/collection/ring.go      |  8 ++++++++
 core/collection/ring_test.go | 28 ++++++++++++++++++++++++++++
 2 files changed, 36 insertions(+)

diff --git a/core/collection/ring.go b/core/collection/ring.go
index 0690fd8f..1c2ab763 100644
--- a/core/collection/ring.go
+++ b/core/collection/ring.go
@@ -1,8 +1,11 @@
 package collection
 
+import "sync"
+
 type Ring struct {
 	elements []interface{}
 	index    int
+	lock     sync.Mutex
 }
 
 func NewRing(n int) *Ring {
@@ -16,11 +19,16 @@ func NewRing(n int) *Ring {
 }
 
 func (r *Ring) Add(v interface{}) {
+	r.lock.Lock()
+	defer r.lock.Unlock()
 	r.elements[r.index%len(r.elements)] = v
 	r.index++
 }
 
 func (r *Ring) Take() []interface{} {
+	r.lock.Lock()
+	defer r.lock.Unlock()
+
 	var size int
 	var start int
 	if r.index > len(r.elements) {
diff --git a/core/collection/ring_test.go b/core/collection/ring_test.go
index 110170e0..8f44c1fd 100644
--- a/core/collection/ring_test.go
+++ b/core/collection/ring_test.go
@@ -1,6 +1,7 @@
 package collection
 
 import (
+	"sync"
 	"testing"
 
 	"github.com/stretchr/testify/assert"
@@ -29,3 +30,30 @@ func TestRingMore(t *testing.T) {
 	elements := ring.Take()
 	assert.ElementsMatch(t, []interface{}{6, 7, 8, 9, 10}, elements)
 }
+
+func BenchmarkRingAdd(b *testing.B) {
+	ring := NewRing(500)
+	b.RunParallel(func(pb *testing.PB) {
+		for pb.Next() {
+			for i := 0; i < b.N; i++ {
+				ring.Add(i)
+			}
+		}
+	})
+}
+
+func TestRingAdd(t *testing.T) {
+	ring := NewRing(5051)
+	wg := sync.WaitGroup{}
+	for i := 1; i <= 100; i++ {
+		wg.Add(1)
+		go func(i int) {
+			defer wg.Done()
+			for j := 1; j <= i; j++ {
+				ring.Add(i)
+			}
+		}(i)
+	}
+	wg.Wait()
+	assert.Equal(t, 5050, len(ring.Take()))
+}