88 lines
2.0 KiB
Markdown
88 lines
2.0 KiB
Markdown
### 泄漏的大多数原因
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- Goroutine 内正在进行 channel/mutex 等读写操作，但由于逻辑问题，某些情况下会被一直阻塞。
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- Goroutine 内的业务逻辑进入死循环，资源一直无法释放。
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- Goroutine 内的业务逻辑进入长时间等待，有不断新增的 Goroutine 进入等待
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#### channel发送不接收
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- 开启多个goroutine，写channel
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- 只读了部分的channel，导致goroutine阻塞不会释放
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```go
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package main
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func main() {
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for i := 0; i < 4; i++ {
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queryAll()
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fmt.Printf("goroutines: %d\n", runtime.NumGoroutine())
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}
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}
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func queryAll() int {
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ch := make(chan int)
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for i := 0; i < 3; i++ {
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go func() { ch <- query() }()
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}
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// 开启多个channel，只接收了一个
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return <-ch
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}
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func query() int {
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n := rand.Intn(100)
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time.Sleep(time.Duration(n) * time.Millisecond)
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return n
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}
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```
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#### channel接收不发送
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- 只开启了接收，但是没有goroutine去发送数据到channel
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```go
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func main() {
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defer func() {
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fmt.Println("goroutines: ", runtime.NumGoroutine())
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}()
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var ch chan struct{}
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go func() {
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ch <- struct{}{}
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}()
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time.Sleep(time.Second)
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}
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```
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#### nil channel 读写都会阻塞goroutine
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```go
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ch := make(chan int)
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go func() {
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<-ch
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}()
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ch <- 0
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time.Sleep(time.Second)
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```
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#### 请求三方接口没有设置超时等待
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```go
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func main() {
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for {
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go func() {
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_, err := http.Get("https://www.xxx.com/")
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if err != nil {
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fmt.Printf("http.Get err: %v\n", err)
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}
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// do something...
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}()
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time.Sleep(time.Second * 1)
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fmt.Println("goroutines: ", runtime.NumGoroutine())
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}
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}
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```
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#### 互斥锁忘记解锁
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- 互斥锁上锁后，忘记解锁
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- 造成其他goroutine锁等待，进而产生资源泄漏
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- `defer lock.Unlock()`
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#### 同步锁使用不当
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- sync.WaitGroup
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- `Add`的数量和`Done`的数量不一致
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- `Wait`方法一直阻塞 |