What is the role of the Context.Done method in managing the completion of asynchronous operations?

The Context.Done() method returns a channel that is closed when the context is canceled or its deadline expires. This allows asynchronous operations to monitor the completion signal and terminate properly.

For example, in a goroutine, you can listen to this channel and end the work when the context is canceled:

ctx, cancel := context.WithCancel(context.Background())
go func() {
    select {
    case <-ctx.Done():
        // Context canceled, end work
        return
    case data := <-dataCh:
        // Process data
    }
}()

// Later, call cancel() to stop the goroutine
cancel()

Thus, Context.Done() serves as a signal for safe and timely termination of asynchronous operations.