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