atomic.SwapUint64() Function in Golang With Examples

In Go language, atomic packages supply lower-level atomic memory that is helpful is implementing synchronization algorithms. The SwapUint64() function in Go language is used to atomically store new value into *addr and returns the previous *addr value. This function is defined under the atomic package. Here, you need to import "sync/atomic" package in order to use these functions. Syntax:

func SwapUint64(addr *uint64, new uint64) (old uint64)

Here, addr indicates address. And new is the new uint64 value and old is the older uint64 value. Note: (*uint64) is the pointer to a uint64 value. And uint64 is an integer type of bit size 64. However, uint64 contains the set of all unsigned 64-bit integers from 0 to 18446744073709551615. Return value: It stores the new uint64 value into the *addr and returns the previous *addr value. Example 1: C

// Program to illustrate the usage of
// SwapUint64 function in Golang

// Including main package
package main

// Importing fmt and sync/atomic
import (
    "fmt"
    "sync/atomic"
)

// Main function
func main() {

    // Assigning value to uint64
    var x uint64 = 10864545453

    // Using SwapUint64 method
    // with its parameters
    var old_val = atomic.SwapUint64(&x, 65353443)

    // Prints new and old value
    fmt.Println("Stored new value: ",
         x, ", Old value: ", old_val)
}

Output:

Stored new value:  65353443, Old value:  10864545453

Example 2: C

// Program to illustrate the usage of
// SwapUint64 function in Golang

// Including main package
package main

// Importing fmt and sync/atomic
import (
    "fmt"
    "sync/atomic"
)

// Main function
func main() {

    // Assigning value to uint64
    var m uint64 = 11735344343
    var n uint64 = 976364747

    // Using SwapUint64 method
    //  with its parameters
    var oldVal1 = atomic.SwapUint64(&m, 11735344343)
    var oldVal2 = atomic.SwapUint64(&n, 6586850111)

    // Prints output
    fmt.Println((oldVal1) == m)
    fmt.Println((oldVal2) == n)
}

Output:

true
false

Here, the oldVal1 is equal to "m" as the new value to be stored in the *addr is same as an old value so, true is returned but oldVal2 is not equal to "n" as there the old value is not similar to the newly assigned value hence, false is returned.