feat: Substitute mutex with atomic operations.

Use atomic operations instead a mutex. This approach avoids locking and
increment can be done within a single clock cycle, hence no deadlock nor
race condition can occur.

Signed-off-by: Ville Valkonen <weezel@users.noreply.github.com>

filepicker/filepicker.go

@@ -7,25 +7,20 @@ import (
  "sort"
  "strconv"
  "strings"
- "sync"
+ "sync/atomic"
 
  "github.com/charmbracelet/bubbles/key"
  tea "github.com/charmbracelet/bubbletea"
  "github.com/charmbracelet/lipgloss"
  "github.com/dustin/go-humanize"
 )
 
-var (
- lastID int
- idMtx sync.Mutex
-)
+var lastID atomic.Int64
 
 // Return the next ID we should use on the Model.
 func nextID() int {
- idMtx.Lock()
- defer idMtx.Unlock()
- lastID++
- return lastID
+ lastID.Add(1)
+ return int(lastID.Load())
 }
 
 // New returns a new filepicker model with default styling and key bindings.