// and nonce. A *Cipher implements the cipher.Stream interface.
type Cipher struct {
	// The ChaCha20 state is 16 words: 4 constant, 8 of key, 1 of counter
	// (incremented after each block), and 3 of nonce.
	key     [8]uint32
	counter uint32
	nonce   [3]uint32

	// The last len bytes of buf are leftover key stream bytes from the previous

of the expected endian order. If 'BR' is used then zero extend is assumed.

Memory references n(Ra) indicate the address in Ra + n. When used with an update form
of an opcode, the value in Ra is incremented by n.

Memory references (Ra+Rb) or (Ra)(Rb) indicate the address Ra + Rb, used by indexed
loads or stores. Both forms are accepted. When used with an update then the base register
is updated by the value in the index register.

// function.
//
//go:nosplit
func (m *consistentHeapStats) acquire() *heapStatsDelta {
	if pp := getg().m.p.ptr(); pp != nil {
		seq := pp.statsSeq.Add(1)
		if seq%2 == 0 {
			// Should have been incremented to odd.
			print("runtime: seq=", seq, "\n")
			throw("bad sequence number")
		}
	} else {
		lock(&m.noPLock)
	}
	gen := m.gen.Load() % 3
	return &m.stats[gen]
}

//
// It must be kept in sync with the sync package.
type notifyList struct {
	// wait is the ticket number of the next waiter. It is atomically
	// incremented outside the lock.
	wait atomic.Uint32

	// notify is the ticket number of the next waiter to be notified. It can
	// be read outside the lock, but is only written to with lock held.
	//

)

// A file is a counter file.
type file struct {
	// Linked list of all known counters.
	// (Linked list insertion is easy to make lock-free,
	// and we don't want the initial counters incremented
	// by a program to cause significant contention.)
	counters atomic.Pointer[Counter] // head of list
	end      Counter                 // list ends at &end instead of nil

	mu         sync.Mutex
	namePrefix string

	// PollDesc objects must be type-stable,
	// because we can get ready notification from epoll/kqueue
	// after the descriptor is closed/reused.
	// Stale notifications are detected using seq variable,
	// seq is incremented when deadlines are changed or descriptor is reused.
}

var (
	netpollInitLock mutex
	netpollInited   atomic.Uint32

	pollcache      pollCache
	netpollWaiters atomic.Uint32
)

	Currently, it is:
		gc # @#s #%: #+#+# ms clock, #+#/#/#+# ms cpu, #->#-># MB, # MB goal, # MB stacks, #MB globals, # P
	where the fields are as follows:
		gc #         the GC number, incremented at each GC
		@#s          time in seconds since program start
		#%           percentage of time spent in GC since program start
		#+...+#      wall-clock/CPU times for the phases of the GC

	locksHeld    [10]heldLockInfo
}

type p struct {
	id          int32
	status      uint32 // one of pidle/prunning/...
	link        puintptr
	schedtick   uint32     // incremented on every scheduler call
	syscalltick uint32     // incremented on every system call
	sysmontick  sysmontick // last tick observed by sysmon
	m           muintptr   // back-link to associated m (nil if idle)
	mcache      *mcache
	pcache      pageCache

}

func (fw *funcWriter) Write(b []byte) (int, error) {
	return fw.write(b)
}

func TestRacyOutput(t *T) {
	var runs int32  // The number of running Writes
	var races int32 // Incremented for each race detected
	raceDetector := func(b []byte) (int, error) {
		// Check if some other goroutine is concurrently calling Write.
		if atomic.LoadInt32(&runs) > 0 {
			atomic.AddInt32(&races, 1) // Race detected!

	// Error is called for each error encountered. If no Error
	// function is set, the error is reported to os.Stderr.
	Error func(s *Scanner, msg string)

	// ErrorCount is incremented by one for each error encountered.
	ErrorCount int

	// The Mode field controls which tokens are recognized. For instance,
	// to recognize Ints, set the ScanInts bit in Mode. The field may be
	// changed at any time.