future-blog-post-17

new_context.go

func NewWithContext(ctx context.Context, inFunc Process) Interface {
    f := New(inFunc).(*futureImpl)
    c := ctx.Done()
    if c != nil {
        go func() {
            select {
            case <-c:
                //if context is cancelled, cancel future
                f.Cancel()
            case <-f.cancel:
                //do nothing, cancelled future doesn’t cancel context
            case <-f.done:
                //do nothing, done future doesn’t cancel context
            }
        }()
    }
    return f
}