MOVKW $(3905<<0), R21                      // MOVKW $3905, R21              // 35e88172
	MOVKW $(3905<<16), R21                     // MOVKW $255918080, R21         // 35e8a172
	MOVK $(3905<<32), R21                      // MOVK $16771847290880, R21     // 35e8c1f2
	MOVD $0, R5                                // e5031faa
	MSR $1, SPSel                              // bf4100d5
	MSR $9, DAIFSet                            // df4903d5

pkg syscall (netbsd-arm-cgo), func Pipe2([]int, int) error
pkg syscall (openbsd-386), const SOCK_CLOEXEC = 32768
pkg syscall (openbsd-386), const SOCK_CLOEXEC ideal-int
pkg syscall (openbsd-386), const SOCK_NONBLOCK = 16384
pkg syscall (openbsd-386), const SOCK_NONBLOCK ideal-int
pkg syscall (openbsd-386), const SYS_ACCEPT4 = 93
pkg syscall (openbsd-386), const SYS_ACCEPT4 ideal-int

	STP	(R26, R27), 700(R2)                              // ERROR "cannot use REGTMP as source"
	MOVK	$0, R10                                          // ERROR "zero shifts cannot be handled correctly"
	MOVK	$(0<<32), R10                                    // ERROR "zero shifts cannot be handled correctly"
	TLBI	PLDL1KEEP                                        // ERROR "illegal argument"

var tmpdir string

var (
	devID    string
	appID    string
	teamID   string
	bundleID string
	deviceID string
)

// lock is a file lock to serialize iOS runs. It is global to avoid the
// garbage collector finalizing it, closing the file and releasing the
// lock prematurely.
var lock *os.File

func main() {
	log.SetFlags(0)
	log.SetPrefix("go_ios_exec: ")
	if debug {
		log.Println(strings.Join(os.Args, " "))
	}

	// https://issuetracker.google.com/issues/73230216.
	lockPath := filepath.Join(os.TempDir(), "go_android_exec-adb-lock")
	lock, err := os.OpenFile(lockPath, os.O_CREATE|os.O_RDWR, 0666)
	if err != nil {
		return 0, err
	}
	defer lock.Close()
	if err := syscall.Flock(int(lock.Fd()), syscall.LOCK_EX); err != nil {
		return 0, err
	}

	// In case we're booting a device or emulator alongside all.bash, wait for

var a string

func f() {
	a = "hello, world"
	l.Unlock()
}

func main() {
	l.Lock()
	go f()
	l.Lock()
	print(a)
}
</pre>

<p>
is guaranteed to print <code>"hello, world"</code>.
The first call to <code>l.Unlock()</code> (in <code>f</code>) is synchronized
before the second call to <code>l.Lock()</code> (in <code>main</code>) returns,
which is sequenced before the <code>print</code>.
</p>