atomic.LoadPointer() Function in Golang With Examples

In Go language, atomic packages supply lower level atomic memory that is helpful is implementing synchronization algorithms. The LoadPointer() function in Go language is used to atomically load *addr. This function is defined under the atomic package. Here, you need to import “sync/atomic” and “unsafe” package in order to use these functions.
Syntax:

func LoadPointer(addr *unsafe.Pointer) (val unsafe.Pointer)

Here, addr indicates address.
Note: (*unsafe.Pointer) is the pointer to a unsafe.Pointer value. And unsafe.Pointer type is helpful in enabling transitions between arbitrary types and builtin uintptr type. Moreover, unsafe is a package that is helpful in type safety of Go programs.
Return Value: It automatically loads *addr and returns unsafe.Pointer.
Example 1:

C

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

// Including main package
package main

// importing fmt,
// sync/atomic and unsafe
import (
    "fmt"
    "sync/atomic"
    "unsafe"
)

// Defining a struct type L
type L struct{ x, y, z int }

// Declaring pointer
// to L struct type
var PL *L

// Calling main
func main() {

    // Defining *addr unsafe.Pointer
    var unsafepL = (*unsafe.Pointer)(unsafe.Pointer(&PL))

    // Defining value
    // of unsafe.Pointer
    var px L

    // Calling StorePointer and
    // storing unsafe.Pointer
    // value to *addr
    atomic.StorePointer(
        unsafepL, unsafe.Pointer(&px))

    // Calling LoadPointer() method
    px1 := (*L)(atomic.LoadPointer(unsafepL))

    // Returns true if *addr is
    // loaded else returns false
    fmt.Println(px1 == &px)

    // Prints unsafe.Pointer
    fmt.Println(&px1)
}

Output:

true
0xc0000b8018 // Can be different at different run times

Here, the StorePointer method adds value to the *addr and then LoadPointer method atomically loads *addr. So, here loading is accomplished hence, true is returned and the value of unsafe.Pointer returned here can be different at different run times.
Example 2:

C

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

// Including main package
package main

// importing fmt,
// sync/atomic and unsafe
import (
    "fmt"
    "sync/atomic"
    "unsafe"
)

// Defining a struct type L
type L struct{ x, y, z int }

// Declaring pointer
// to L struct type
var PL *L

// Calling main
func main() {

    // Defining *addr unsafe.Pointer
    var unsafepL = (*unsafe.Pointer)(unsafe.Pointer(&PL))

    // Defining value
    // of unsafe.Pointer
    var px L

    // Calling LoadPointer() method
    px1 := (*L)(atomic.LoadPointer(unsafepL))

    // Returns true if *addr is
    // loaded else returns false
    fmt.Println(px1 == &px)

    // Prints unsafe.Pointer
    fmt.Println(&px1)
}

Output:

false
0xc00000e028  // A random value is returned in each run

Here, false is returned as here the unsafe.pointer is not stored before so, LoadPointer() method was not able to load the *addr. Moreover, the address value returned here is the address of px1.