// If five in a row all fail, give up.
		if fails++; fails >= 5 {
			panic(fmt.Sprintf("%s: too slow: %d channels: %v; %d channels: %v\n",
				typ, n, t1, 2*n, t2))
		}
	}
}

func main() {
	checkLinear("chanSelect", 1000, func(n int) {
		const messages = 10
		c := make(chan bool) // global channel
		var a []chan bool    // local channels for each goroutine
		for i := 0; i < n; i++ {
			d := make(chan bool)
			a = append(a, d)

				Send: val,
			})
			info = append(info, caseInfo{desc: "ready send", canSelect: true})
		}

		// Ready recv.
		if x.Maybe() {
			ch, val := newop(len(cases), 1)
			ch.Send(val)
			cases = append(cases, SelectCase{
				Dir:  SelectRecv,
				Chan: ch,
			})
			info = append(info, caseInfo{desc: "ready recv", canSelect: true, recv: val})
		}

		// Blocking send.
		if x.Maybe() {