Mastering Go - Second Edition

What happens if you forget to unlock a mutex?

In this section, you will see what happens if you forget to unlock a sync.Mutex. You will do this using the Go code of forgetMutex.go, which will be presented in two parts.

The first part of forgetMutex.go is shown in the following Go code:

package main 
 
import ( 
    "fmt" 
    "sync" 
) 
 
var m sync.Mutex 
 
func function() { 
    m.Lock() 
    fmt.Println("Locked!") 
} 

All of the problems in this program are caused because the developer forgot to release the lock to m sync.Mutex. However, if your program is going to call function() only once, then everything will look just fine.

The second part of forgetMutex.go is as follows:

func main() { var w sync.WaitGroup go func() { defer w.Done() function() }() w.Add(1) go func() ...