wg.Wait()
	if fails > attempts/9 { // see issues 7400 and 7541
		t.Fatalf("too many Dial failed: %v", fails)
	}
	if fails > 0 {
		t.Logf("# of failed Dials: %v", fails)
	}
}

func TestTCPReadWriteAllocs(t *testing.T) {
	switch runtime.GOOS {
	case "plan9":
		// The implementation of asynchronous cancelable
		// I/O on Plan 9 allocates memory.
		// See net/fd_io_plan9.go.