# Use go.uber.org/atomic

Atomic operations with the [sync/atomic] package operate on the raw types
(`int32`, `int64`, etc.) so it is easy to forget to use the atomic operation to
read or modify the variables.

[go.uber.org/atomic] adds type safety to these operations by hiding the
underlying type. Additionally, it includes a convenient `atomic.Bool` type.

  [go.uber.org/atomic]: https://pkg.go.dev/go.uber.org/atomic
  [sync/atomic]: https://pkg.go.dev/sync/atomic

<table>
<thead><tr><th>Bad</th><th>Good</th></tr></thead>
<tbody>
<tr><td>

```go
type foo struct {
  running int32  // atomic
}

func (f *foo) start() {
  if atomic.SwapInt32(&f.running, 1) == 1 {
     // already running…
     return
  }
  // start the Foo
}

func (f *foo) isRunning() bool {
  return f.running == 1  // race!
}
```

</td><td>

```go
type foo struct {
  running atomic.Bool
}

func (f *foo) start() {
  if f.running.Swap(true) {
     // already running…
     return
  }
  // start the Foo
}

func (f *foo) isRunning() bool {
  return f.running.Load()
}
```

</td></tr>
</tbody></table>