英文:
Go maps fails the concurency test
问题
当我运行以下代码时：
import ("log""sync""testing""time")func TestConcurrency(t *testing.T) {var mutex sync.RWMutexdictionary := make(map[interface{}]interface{})go func() {var value interface{}for {go func() {mutex.Lock()dictionary["Key"] = ""mutex.Unlock()}()go func() {mutex.RLock()value = dictionary["Key"]mutex.RUnlock()}()}log.Println(value)}()}
使用：
go test -race fileName.go
结果是：
发现1个数据竞争我该如何解决这个问题？我有很多并发的写入和读取操作。
英文:
When I run the following code:
import ("log""sync""testing""time")func TestConcurrency(t *testing.T) {var mutex sync.RWMutexdictionary := make(map[interface{}]interface{})go func() {var value interface{}for {go func() {mutex.Lock()dictionary["Key"] = ""mutex.Unlock()}()go func() {mutex.RLock()value = dictionary["Key"]mutex.RUnlock()}()}log.Println(value)}()}
using :
go test -race fileName.go
It results in:
Found 1 data race(s)
How can I solve this?
I have many concurrent writes and reads.
答案1
得分: 4
如果你查看竞争检测器报告的错误，你会发现它报告了在value = dictionary["Key"]这一行上的并发写操作，这意味着检测到的竞争是在value而不是dictionary上。
你同时访问了两个变量，dictionary和value。你不能使用读锁来保护对映射的读取和对value变量的写入。你要么需要第二个互斥锁，要么需要始终使用mutex.Lock来串行访问这两个变量。
英文:
If you look at the error presented by the race detector, you would see that it reported concurrent writes on the value = dictionary["Key"] line, meaning the race being detected is on value, not dictionary.
You are concurrently accessing 2 variables, dictionary and value. You can't use the read lock to protect reads on the map, and writes to the value variable. You either need a second mutex, or you need to always use mutex.Lock to serialize access to both variables.
答案2
得分: 0
这段代码将正常工作：
go func() {mutex.Lock()value = dictionary["Key"]mutex.Unlock()}()
它保护变量value免受并发写入的影响。
英文:
This code will work correctly:
go func() {mutex.Lock()value = dictionary["Key"]mutex.Unlock()}()
It protects the variable value from concurrent write.
通过集体智慧和协作来改善编程学习和解决问题的方式。致力于成为全球开发者共同参与的知识库，让每个人都能够通过互相帮助和分享经验来进步。
评论