Mutual Exclusion of Concurrent Goroutines

Question

In my code there are three concurrent routines. I try to give a brief overview of my code,

Routine 1 {
do something

*Send int to Routine 2
Send int to Routi         


        

Answer 1

You could use sync.Mutex. For example everything between im.Lock() and im.Unlock() will exclude the other goroutine.

package main

import (
"fmt"
"sync"
)

func f1(wg *sync.WaitGroup, im *sync.Mutex, i *int) {
  for {
    im.Lock()
    (*i)++
    fmt.Printf("Go1: %d\n", *i)
    done := *i >= 10
    im.Unlock()
    if done {
      break
    }
  }
  wg.Done()
}

func f2(wg *sync.WaitGroup, im *sync.Mutex, i *int) {
  for {
    im.Lock()
    (*i)++
    fmt.Printf("Go2: %d\n", *i)
    done := *i >= 10
    im.Unlock()
    if done {
      break
    }
  }
  wg.Done()
}

func main() {
    var wg sync.WaitGroup

    var im sync.Mutex
    var i int

    wg.Add(2)
    go f1(&wg, &im, &i)
    go f2(&wg, &im, &i)
    wg.Wait()   

}