if srv.listener == nil {
		srv.listenerMutex.Unlock()
		return http.ErrServerClosed
	}
	srv.listenerMutex.Unlock()

	if atomic.AddUint32(&srv.inShutdown, 1) > 1 {
		// shutdown in progress
		return http.ErrServerClosed
	}

	// Close underneath HTTP listener.
	srv.listenerMutex.Lock()
	err := srv.listener.Close()
	srv.listenerMutex.Unlock()
	if err != nil {
		return err
	}

 *
 * <ul>
 *   <li>for an unnested {@code lock()} and {@code unlock()}, a cycle detecting lock takes 38ns as
 *       opposed to the 24ns taken by a plain lock.
 *   <li>for nested locking, the cost increases with the depth of the nesting:
 *       <ul>
 *         <li>2 levels: average of 64ns per lock()/unlock()
 *         <li>3 levels: average of 77ns per lock()/unlock()
 *         <li>4 levels: average of 99ns per lock()/unlock()

// IsClosed - Check if the rlocked file is already closed.
func (r *RLockedFile) IsClosed() bool {
	r.mutex.Lock()
	defer r.mutex.Unlock()
	return r.refs == 0
}

// IncLockRef - is used by called to indicate lock refs.
func (r *RLockedFile) IncLockRef() {
	r.mutex.Lock()
	r.refs++
	r.mutex.Unlock()
}

// Close - this closer implements a special closer
// closes the underlying fd only when the refs
// reach zero.

  }

  @Override
  public boolean tryLock(long time, TimeUnit unit) throws InterruptedException {
    return delegate().tryLock(time, unit);
  }

  @Override
  public void unlock() {
    delegate().unlock();
  }

  @Override
  public Condition newCondition() {
    return delegate().newCondition();
  }

	if err = rlk.Close(); err != os.ErrInvalid {
		t.Fatal(err)
	}

	_, err = newRLockedFile(nil)
	if err != os.ErrInvalid {
		t.Fatal("Unexpected error", err)
	}
}

// Tests lock and unlock semantics.
func TestLockAndUnlock(t *testing.T) {
	f, err := os.CreateTemp(t.TempDir(), "lock")
	if err != nil {
		t.Fatal(err)
	}
	f.Close()
	defer func() {
		err = os.Remove(f.Name())

func (r *lockedRandSource) Int63() (n int64) {
	r.lk.Lock()
	n = r.src.Int63()
	r.lk.Unlock()
	return n
}

// Seed uses the provided seed value to initialize the generator to a
// deterministic state.
func (r *lockedRandSource) Seed(seed int64) {
	r.lk.Lock()
	r.src.Seed(seed)
	r.lk.Unlock()

		l.IDMap[id] = prev
		shouldLog = false
	}
	l.Unlock()

	if shouldLog {
		logIf(ctx, subsystem, err, errKind...)
	}
}

// Cleanup the map every one hour so that the log message is printed again for the user to notice.
func (l *logOnceType) cleanupRoutine() {
	for {
		time.Sleep(time.Hour)

		l.Lock()
		l.IDMap = make(map[string]onceErr)
		l.Unlock()
	}
}

// Returns logOnceType

call <i>n</i> of <code>l.Unlock()</code> is synchronized before call <i>m</i> of <code>l.Lock()</code> returns.
</p>

<p>
This program:
</p>

<pre>
var l sync.Mutex
var a string

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

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

		// - xl.meta metadata is still verified for quorum under lock()
		//   however writing the response doesn't need to serialize
		//   concurrent writers
		unlockOnDefer = true
		nsUnlocker = func() { lock.RUnlock(lkctx) }
	}

	fi, metaArr, onlineDisks, err := er.getObjectFileInfo(ctx, bucket, object, opts, true)
	if err != nil {
		return nil, toObjectErr(err, bucket, object)
	}

	bootstrapTraceMsg("IAM initialization started")
	globalServerConfigMu.RLock()
	s := globalServerConfig
	globalServerConfigMu.RUnlock()

	sys.Lock()
	sys.iamRefreshInterval = iamRefreshInterval
	sys.Unlock()

	r := rand.New(rand.NewSource(time.Now().UnixNano()))

	var (
		openidInit bool
		ldapInit   bool
		authNInit  bool
		authZInit  bool
	)