mfe.tables["nat"].Len() == 0
}

func waitForReloads(reloads *uint32, expected uint32) error {
	if atomic.LoadUint32(reloads) < expected {
		utilwait.PollImmediate(100*time.Millisecond, time.Second, func() (bool, error) {
			return atomic.LoadUint32(reloads) >= expected, nil
		})
	}
	got := atomic.LoadUint32(reloads)
	if got != expected {
		return fmt.Errorf("expected %d, got %d", expected, got)
	}
	return nil
}

type lazyInit struct {
	done uint32
	m    sync.Mutex
}

func (l *lazyInit) Do(f func() error) error {
	if atomic.LoadUint32(&l.done) == 0 {
		return l.doSlow(f)
	}
	return nil
}

func (l *lazyInit) doSlow(f func() error) error {
	l.m.Lock()
	defer l.m.Unlock()
	if atomic.LoadUint32(&l.done) == 0 {
		if err := f(); err != nil {
			return err
		}
		// Mark as done only when f() is successful

	}()
	// Also test empty infinite loop.
	go func() {
		atomic.AddUint32(&ready2, 1)
		for {
		}
	}()

	// Wait for the goroutine to stop passing through sync
	// safe-points.
	for atomic.LoadUint32(&ready) == 0 || atomic.LoadUint32(&ready2) < 2 {
		runtime.Gosched()
	}

	// Run a GC, which will have to stop the goroutine for STW and
	// for stack scanning. If this doesn't work, the test will
	// deadlock and timeout.

// 'go tool cover'.
func Coverage() float64 {
	if goexperiment.CoverageRedesign {
		return coverage2()
	}
	var n, d int64
	for _, counters := range cover.Counters {
		for i := range counters {
			if atomic.LoadUint32(&counters[i]) > 0 {
				n++
			}
			d++
		}
	}
	if d == 0 {
		return 0
	}
	return float64(n) / float64(d)
}

// RegisterCover records the coverage data accumulators for the tests.

type safeCloser struct {
	closed uint32
	r      io.Reader
}

func (s *safeCloser) Read(p []byte) (n int, err error) {
	if atomic.LoadUint32(&s.closed) == 1 {
		return 0, io.EOF
	}
	n, err = s.r.Read(p)
	if atomic.LoadUint32(&s.closed) == 1 {
		return 0, io.EOF
	}
	return n, err
}

func (s *safeCloser) Close() error {
	atomic.CompareAndSwapUint32(&s.closed, 0, 1)

	}
	close(done)
}

// Don't inline this function, since we want to test adjusting
// pointers in the arguments.
//
//go:noinline
func debugCallWorker2(stop *uint32, x *int) {
	for atomic.LoadUint32(stop) == 0 {
		// Strongly encourage x to live in a register so we
		// can test pointer register adjustment.
		*x++
	}
	*x = 1
}

func debugCallTKill(tid int) error {

	var stop uint32
	defer atomic.StoreUint32(&stop, 1) // in case of panic

	var wg sync.WaitGroup
	for i := 0; i < 4; i++ {
		wg.Add(1)
		go func() {
			for atomic.LoadUint32(&stop) == 0 {
				syscall.Close(-1)
			}
			wg.Done()
		}()
	}

	max := 10000
	if testing.Short() {
		max = 100
	}
	stk := make([]runtime.StackRecord, 128)
	for n := 0; n < max; n++ {

	// Note: these are disabled by flag_race in findIntrinsic below.
	alias("sync/atomic", "LoadInt32", "internal/runtime/atomic", "Load", all...)
	alias("sync/atomic", "LoadInt64", "internal/runtime/atomic", "Load64", all...)
	alias("sync/atomic", "LoadPointer", "internal/runtime/atomic", "Loadp", all...)
	alias("sync/atomic", "LoadUint32", "internal/runtime/atomic", "Load", all...)

		// Check that this goroutine is running on a different thread.
		self := C.pthread_self()
		if C.pthread_equal(subThread, self) != 0 {
			println("locked thread reused")
			os.Exit(1)
		}
		if atomic.LoadUint32((*uint32)(&C.threadExited)) != 0 {
			println("OK")
			return
		}
	}

	if err != nil {
		t.Fatalf("mprotect high failed %s\n", err)
	}

	// This should not fault.
	a := (*uint32)(unsafe.Pointer(&b[pagesize-4]))
	atomic.StoreUint32(a, 1)
	if x := atomic.LoadUint32(a); x != 1 {
		t.Fatalf("bad atomic value: %v, want 1", x)
	}
	if x := atomic.AddUint32(a, 1); x != 2 {
		t.Fatalf("bad atomic value: %v, want 2", x)
	}