How to cancel a deferred statement

Question

I have the following code structure where I Lock() at point A and need to definitely Unlock() at a point B in the same function. Between point A and B, I have multiple returns b

Answer 1

It is not possible to cancel a deferred function.

Use a local variable to record the function's state with respect to the lock and check that variable in the deferred function.

lock.Lock()
locked := true

defer func() {
    if locked  {
        lock.Unlock()
    }
}()
...
err := bar()
if err != nil {
    return
}
...

lock.Unlock()
locked = false

...

Because locks are generally used in a multithreaded environment, it should be noted that the function local variable locked should only accessed by a single goroutine (thank you Rick-777 for calling this out in a comment).