// Thus even if a type can be inferred successfully, the function
// call may not be valid.

func fboth[T any](chan T) {}
func frecv[T any](<-chan T) {}
func fsend[T any](chan<- T) {}

func _() {
	var both chan int
	var recv <-chan int
	var send chan<-int

	fboth(both)
	fboth(recv /* ERROR "cannot use" */ )
	fboth(send /* ERROR "cannot use" */ )

	frecv(both)
	frecv(recv)

	}
	Println("did exec")
}

func stressExec() {
	gate := make(chan bool, 10) // max execs at once
	for {
		gate <- true
		go func() {
			doAnExec()
			<-gate
		}()
	}
}

func ringf(in <-chan int, out chan<- int, donec chan bool) {
	for {
		var n int
		select {
		case <-donec:
			return
		case n = <-in:
		}
		if n == 0 {

		if debugPrint {
			fmt.Println("connected stream mux:", ack.MuxID)
		}
	}()

	// Data inbound to the handler
	var handlerIn chan []byte
	if inboundCap > 0 {
		m.inbound = make(chan []byte, inboundCap)
		handlerIn = make(chan []byte, 1)
		go func(inbound chan []byte) {
			wg.Wait()
			defer xioutil.SafeClose(handlerIn)
			m.handleInbound(c, inbound, handlerIn)
		}(m.inbound)
	}

	// maps
	dup("map[string]int"),
	{"map[struct{x, y int}][]byte", "map[struct{x int; y int}][]byte"},

	// channels
	dup("chan<- chan int"),
	dup("chan<- <-chan int"),
	dup("<-chan <-chan int"),
	dup("chan (<-chan int)"),
	dup("chan<- func()"),
	dup("<-chan []func() int"),
}

// types that depend on other type declarations (src in TestTypes)
var dependentTestTypes = []testEntry{
	// interfaces

	go func() { // func1
		select {}
	}()
	go func() { // func2
		var c chan int
		c <- 0
	}()
	go func() { // func3
		var c chan int
		<-c
	}()
	done1 := make(chan bool)
	go func() { // func4
		<-done1
	}()
	done2 := make(chan bool)
	go func() { // func5
		done2 <- true
	}()
	c1 := make(chan int)
	c2 := make(chan int)
	go func() { // func6
		select {
		case <-c1:
		case <-c2:
		}

	{"midstack_inlining_traceback", "run", "linux", "atexit_sleep_ms=0", `
package main

var x int
var c chan int
func main() {
	c = make(chan int)
	go f()
	x = 1
	<-c
}

func f() {
	g(c)
}

func g(c chan int) {
	h(c)
}

func h(c chan int) {
	c <- x
}
`, []string{`==================
WARNING: DATA RACE
Read at 0x[0-9,a-f]+ by goroutine [0-9]:

			// iteration is 2 * (runtime overhead + chan
			// send/receive pair + delay + wakeDelay). This allows
			// the runtime overhead, including the time it takes
			// for the unblocked goroutine to be scheduled, to be
			// estimated.
			ping, pong := make(chan struct{}), make(chan struct{})
			start := make(chan struct{})
			done := make(chan struct{})
			go func() {
				<-start

	_ = p1 == ps1
}

func channels() {
	// basics
	var c, d chan int
	_ = c == d
	_ = c != d
	_ = c == nil
	_ = c /* ERROR "< not defined" */ < d

	// various element types (named types)
	type (
		C1 chan int
		C1r <-chan int
		C1s chan<- int
		C2 chan float32
	)
	var (
		c1 C1
		c1r C1r
		c1s C1s
		c1a chan int
		c2 C2
	)
	_ = c1 == c1

	// maps
	dup("map[string]int"),
	{"map[struct{x, y int}][]byte", "map[struct{x int; y int}][]byte"},

	// channels
	dup("chan<- chan int"),
	dup("chan<- <-chan int"),
	dup("<-chan <-chan int"),
	dup("chan (<-chan int)"),
	dup("chan<- func()"),
	dup("<-chan []func() int"),
}

// types that depend on other type declarations (src in TestTypes)
var dependentTestTypes = []testEntry{
	// interfaces

	for _, s := range os.Args {
		fmt.Fprint(w, s, " ")
	}
}

// a channel (just for the fun of it)
type Chan chan int

func ChanCreate() Chan {
	c := make(Chan)
	go func(c Chan) {
		for x := 0; ; x++ {
			c <- x
		}
	}(c)
	return c
}

func (ch Chan) ServeHTTP(w http.ResponseWriter, req *http.Request) {
	io.WriteString(w, fmt.Sprintf("channel send #%d\n", <-ch))
}