IIFE (Immediately Invoked Function Expression)

Immediately Invoking Anonymous Functions

Usage

Used with defer to control the release timing of resources (e.g., Locks, files, timers).

• To avoid affecting subsequent logic (e.g., email sending, file uploads),
  forcing the clean-up of prior operations to occur sooner.

• When a Lock is required in the initialization logic within a function

  • By declaring defer inside an anonymous function, it is called when the anonymous function's execution (e.g., initialization logic) finishes.
    • Ensuring lock safety: guaranteeing that the Lock is released via defer.

  e.g.

  1func() {
  2	s.startedLock.Lock()
  3	defer s.startedLock.Unlock() // This anonymous function will unlock immediately when it finishes.
  4	// ...
  5}()
  

• defer inside loops

  • ⚠️ Because defer is executed when the function returns, it is not executed immediately within a loop.
  • Create an anonymous function (IIFE) and declare defer along with the logic inside it.