how to make Goroutine not Concurrency if Same Function-CodePudding

Is there any way to make goroutine execute one after another ( one by one) if it was the same function?

I didn't mean to use goroutine firstly. However, "os/exec" function in TCP will cause the tcp forced to stop. Thus I use goroutine to avoid crashing. But I still want them to execute by order, instead of concurrently. Here is my code.

func handleTCP(conn net.Conn) {
    defer conn.Close()
        fmt.Println("handle TCP function")
        for {
              wg := new(sync.WaitGroup)
              wg.Add(1)
              go func() {
                  cmdArgs := []string{temp_str, test_press, gh, "sample.csv"}
                  cmd := exec.Command("calib.exe", cmdArgs...)
                  wg.Done()
              }()
              
        }
}

CodePudding user response：

Try to put the lock into function, it makes theirs execution sequential. But remember about wg.Done() must be under defer at first line of the function. Something like this:

var mu sync.Mutex

func handleTCP(conn net.Conn) {
    defer conn.Close()
        fmt.Println("handle TCP function")
        for {
              wg := new(sync.WaitGroup)
              wg.Add(1)
              go func() {
                  defer wg.Done()
                  mu.Lock()
                  defer mu.UnLock()
                  cmdArgs := []string{temp_str, test_press, gh, "sample.csv"}
                  cmd := exec.Command("calib.exe", cmdArgs...)
                  
              }()
              
        }
}

CodePudding user response：

You can use locks to limit access to a resource to one thread at a time as follows

i := 1
iLock = &sync.Mutex{}

for {
    go func() {
        iLock.Lock()
        fmt.Printf("Value of i: %d\n", i)
        iLock.Unlock()
    }
}

More examples here

Not sure what you are using the WaitGroup for. If it is to achieve the sequentiality you desire, then it can be removed.