In Go language, Atomic Variables are utilized in order to control state. Here, the “sync/atomic” package must be used to use these variables. Moreover, it also prevents race conditions which allows two or more Goroutines to access identical sources. The Atomic counters are available for several goroutines. The main means for managing states in go language is communication over channels.
Example 1:
// Golang program to illustrate the usage of // atomic variable // Including main package package main // Importing sync/atomic, math/rand, // fmt, sync, and time import ( "fmt" "math/rand" "sync" "sync/atomic" "time") // Using sync.WaitGroup in order to // wait for a collection of // goroutines to finish var waittime sync.WaitGroup // Declaring atomic variable var atmvar int32 // Defining increment function func hike(S string) { // For loop for i := 1; i < 7; i++ { // Calling sleep method with its duration // and also calling rand.Intn method time.Sleep(time.Duration((rand.Intn(5))) * time.Millisecond) // Calling AddInt32 method with its // parameter atomic.AddInt32(&atmvar, 1) // Prints output fmt.Println(S, i, "count ->", atmvar) } // Wait completed waittime.Done() } // Main function func main() { // Calling Add method w.r.to // waittime variable waittime.Add(2) // Calling hike method with // values go hike("cat: ") go hike("dog: ") // Calling wait method waittime.Wait() // Prints the value of last count fmt.Println("The value of last count is :", atmvar) } |
Output:
dog: 1 count -> 1 cat: 1 count -> 2 dog: 2 count -> 3 dog: 3 count -> 4 cat: 2 count -> 5 cat: 3 count -> 6 cat: 4 count -> 7 cat: 5 count -> 8 cat: 6 count -> 9 dog: 4 count -> 10 dog: 5 count -> 11 dog: 6 count -> 12 The value of last count is : 12
In the above method, the atomic variable is of type int32. Here, rand.Intn() method is used to print random integer until the loop stops. After that, AddInt32 method is used which adds the atomic variable with another int32 number and then returns it in the count.
Example 2:
// Golang program to illustrate the usage of // AfterFunc() function // Including main package package main // Importing sync/atomic, fmt, // and sync import ( "fmt" "sync" "sync/atomic") // Calling main func main() { // Declaring atomic variable var atmvar uint32 // Using sync.WaitGroup in order to // wait for a collection of // goroutines to finish var wait sync.WaitGroup // For loop for i := 0; i < 30; i += 2 { // Calling Add method wait.Add(1) // Calling AddUint32 method under // go function go func() { atomic.AddUint32(&atmvar, 2) // Wait completed wait.Done() }() } // Calling wait method wait.Wait() // Prints atomic variables value fmt.Println("atmvar:", atmvar) } |
Output:
atmvar: 30
In the above method, the atomic variable is of type uint32. Here, AddUint32() method is used under the for loop which adds its parameters until loop stops and then returns the value of the atomic variable.
