Tell about sync.Atomic: what is it used for, have you used it in your work?

sync/atomic in Go is a package that provides low-level atomic operations on variables (such as read, write, increment) that guarantee safety in concurrent access without using mutexes.

It is used for:

• Ensuring atomicity of operations with integer and pointer types.
• Implementing counters, flags, and state indicators in multithreaded programs.

Example of usage:

import (
    "fmt"
    "sync/atomic"
)

func main() {
    var counter int64 = 0
    atomic.AddInt64(&counter, 1) // atomic increment
    fmt.Println(atomic.LoadInt64(&counter)) // atomic read
}

In practice, I often used sync/atomic to implement high-performance counters and flags, where using mutexes was excessive and could lead to blocking. This helps reduce synchronization overhead and improve scalability.