How does context.WithCancel work with cancellation?

context.WithCancel in Go creates a new context that can be manually canceled. It returns two values: the new context and a cancel function cancel(). When cancel() is called, all operations listening to this context (for example, through <-ctx.Done()) receive a cancellation signal and can terminate properly.

Example usage:

ctx, cancel := context.WithCancel(context.Background())

// Launch a goroutine that listens for cancellation
go func() {
    <-ctx.Done() // wait for cancellation signal
    fmt.Println("Cancellation received, terminating")
}()

// Cancel the context after some time
cancel()

Thus, WithCancel allows coordinating operation cancellations and resource cleanup, which is especially useful for managing the lifecycle of goroutines.