From 80e71d6ee0b6d1fecc22f8bdcf6fe291521ebf35 Mon Sep 17 00:00:00 2001
From: kun <oiooj@qq.com>
Date: Sat, 11 Apr 2020 18:21:11 +0800
Subject: [PATCH] fix(storageflux): fix data race on tags map (#17702)

---
 storage/flux/tags_cache.go | 13 ++++++++++++-
 1 file changed, 12 insertions(+), 1 deletion(-)

diff --git a/storage/flux/tags_cache.go b/storage/flux/tags_cache.go
index f462ebff06..f0b5562583 100644
--- a/storage/flux/tags_cache.go
+++ b/storage/flux/tags_cache.go
@@ -2,6 +2,7 @@ package storageflux
 
 import (
 	"container/list"
+	"sync"
 
 	"github.com/apache/arrow/go/arrow"
 	"github.com/apache/arrow/go/arrow/array"
@@ -39,6 +40,7 @@ type tagsCache struct {
 	// An array can get shared among two different tag keys that
 	// have the same value.
 	tags      map[string]*list.Element
+	mu        sync.RWMutex
 	lru       *list.List
 	maxLength int
 }
@@ -121,7 +123,10 @@ func (c *tagsCache) GetTag(value string, l int, mem memory.Allocator) *array.Bin
 		return c.createTag(value, l, mem)
 	}
 
-	if elem, ok := c.tags[value]; ok {
+	c.mu.RLock()
+	elem, ok := c.tags[value]
+	c.mu.RUnlock()
+	if ok {
 		return c.getOrReplaceTag(elem, value, l, mem)
 	}
 
@@ -129,10 +134,12 @@ func (c *tagsCache) GetTag(value string, l int, mem memory.Allocator) *array.Bin
 	if c.lru == nil {
 		c.lru = list.New()
 	}
+	c.mu.Lock()
 	if c.tags == nil {
 		c.tags = make(map[string]*list.Element)
 	}
 	c.tags[value] = c.lru.PushFront(arr)
+	c.mu.Unlock()
 	c.maintainLRU()
 	arr.Retain()
 	return arr
@@ -180,7 +187,9 @@ func (c *tagsCache) maintainLRU() {
 	}
 	arr := c.lru.Remove(c.lru.Back()).(*array.Binary)
 	value := arr.ValueString(0)
+	c.mu.Lock()
 	delete(c.tags, value)
+	c.mu.Unlock()
 	arr.Release()
 }
 
@@ -206,9 +215,11 @@ func (c *tagsCache) Release() {
 		c.stopColumn = nil
 	}
 
+	c.mu.Lock()
 	for _, elem := range c.tags {
 		elem.Value.(*array.Binary).Release()
 	}
 	c.tags = nil
+	c.mu.Unlock()
 	c.lru = nil
 }