ttk.go
func init() {
	work = make(chan func(), 32)
	keyC = make(chan Key, 1024)
	windows = make(map[int]*Window)
	windower2window = make(map[Windower]*Window)

	// setup render queue
	// we do this song and dance in order to be able to deal with slow
	// connections where rendering could take a long time
	execute := make(chan bool, 1)
	fa := make([]func(), 0, 20)
	mtx := sync.Mutex{}

	var wg sync.WaitGroup
	wg.Add(2)
	go func() {
		wg.Done()
		for range execute {
			for {
				// get work off queue
				mtx.Lock()
				if len(fa) == 0 {
					mtx.Unlock()
					break
				}
				f := fa[0]
				fa[0] = nil // just in case to prevent leak
				fa = fa[1:]
				mtx.Unlock()

				// actually do work
				f()
			}
		}
	}()

	go func() {
		wg.Done()
		for f := range work {
			// queue work
			mtx.Lock()
			fa = append(fa, f)
			mtx.Unlock()

			// tell executer there is work
			select {
			case execute <- true:
			default:
			}
		}
	}()
	wg.Wait()
}
func init() {
	work = make(chan func(), 32)
	keyC = make(chan Key, 1024)
	windows = make(map[int]*Window)
	windower2window = make(map[Windower]*Window)

	// setup render queue
	// we do this song and dance in order to be able to deal with slow
	// connections where rendering could take a long time
	execute := make(chan bool, 1)
	fa := make([]func(), 0, 20)
	mtx := sync.Mutex{}

	var wg sync.WaitGroup
	wg.Add(2)
	go func() {
		wg.Done()
		for range execute {
			for {
				// get work off queue
				mtx.Lock()
				if len(fa) == 0 {
					mtx.Unlock()
					break
				}
				f := fa[0]
				fa[0] = nil // just in case to prevent leak
				fa = fa[1:]
				mtx.Unlock()

				// actually do work
				f()
			}
		}
	}()

	go func() {
		wg.Done()
		for f := range work {
			// queue work
			mtx.Lock()
			fa = append(fa, f)
			mtx.Unlock()

			// tell executer there is work
			select {
			case execute <- true:
			default:
			}
		}
	}()
	wg.Wait()
}
// init sets up all global variables and prepares ttk for use.