}
        } finally {
            lock.writeLock().unlock();
        }
    }
    
    public List<FileInfo> getChildren() {
        lock.readLock().lock();
        try {
            lastAccessTime = System.currentTimeMillis();
            return new ArrayList<>(children.values());
        } finally {
            lock.readLock().unlock();
        }
    }
    

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)
	}

	defer globalAuthPluginMutex.Unlock()
	return globalAuthNPlugin
}

func newGlobalAuthZPluginFn() *polplugin.AuthZPlugin {
	globalAuthPluginMutex.Lock()
	defer globalAuthPluginMutex.Unlock()
	return globalAuthZPlugin
}

func setGlobalAuthNPlugin(authn *idplugin.AuthNPlugin) {
	globalAuthPluginMutex.Lock()
	globalAuthNPlugin = authn
	globalAuthPluginMutex.Unlock()
}

				defer wg.Done()
				err := set.listPath(listCtx, o, innerResults)
				mu.Lock()
				defer mu.Unlock()
				if err == nil {
					allAtEOF = false
				}
				errs[i] = err
			}(len(errs), set)
			errs = append(errs, nil)
		}
	}
	mu.Unlock()

	// Gather results to a single channel.
	// Quorum is one since we are merging across sets.

	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
	)

    lockAndUnlock(factory.newReentrantLock("foo"), reps);
  }

  private static void lockAndUnlock(Lock lock, int reps) {
    for (int i = 0; i < reps; i++) {
      lock.lock();
      lock.unlock();
    }
  }

  @Benchmark
  void orderedPlainLocks(int reps) {
    lockAndUnlockNested(plainLocks, reps);
  }

  @Benchmark
  void orderedCycleDetectingLocks(int reps) {

      lock.lock();
      try {
        condition.await();
      } finally {
        lock.unlock();
      }
    }

    @Override
    public boolean await(long time, TimeUnit unit) throws InterruptedException {
      lock.lock();
      try {
        return condition.await(time, unit);
      } finally {
        lock.unlock();
      }
    }

    @Override
    public void awaitUninterruptibly() {

		s.RUnlock()
		return diskID, nil
	}
	s.RUnlock()

	fi, err := s.checkFormatJSON()
	if err != nil {
		return "", err
	}

	if xioutil.SameFile(fi, fileInfo) && diskID != "" {
		s.Lock()
		// If the file has not changed, just return the cached diskID information.
		s.formatLastCheck = time.Now()
		s.Unlock()
		return diskID, nil
	}

	}

	ctx = plkctx.Context()
	defer partIDLock.Unlock(plkctx)

	// Read lock for upload id, only held while reading the upload metadata.
	uploadIDRLock := er.NewNSLock(bucket, pathJoin(object, uploadID))
	rlkctx, err := uploadIDRLock.GetRLock(ctx, globalOperationTimeout)
	if err != nil {
		return PartInfo{}, err
	}
	ctx = rlkctx.Context()
	defer uploadIDRLock.RUnlock(rlkctx)