private final ReadWriteLock delegate;

    WeakSafeReadWriteLock() {
      this.delegate = new ReentrantReadWriteLock();
    }

    @Override
    public Lock readLock() {
      return new WeakSafeLock(delegate.readLock(), this);
    }

    @Override
    public Lock writeLock() {
      return new WeakSafeLock(delegate.writeLock(), this);
    }
  }

  }

  /**
   * Using this as the blocker object allows introspection and debugging tools to see that the
   * currentRunner thread is blocked on the progress of the interruptor thread, which can help
   * identify deadlocks.
   */
  @VisibleForTesting
  static final class Blocker extends AbstractOwnableSynchronizer implements Runnable {
    private final InterruptibleTask<?> task;

    private Blocker(InterruptibleTask<?> task) {

              isThreadScheduled = false;
              stillRunning = false;
              break;
            }
          }

          // Always run while _not_ holding the lock, to avoid deadlocks.
          try {
            nextToRun.call(listener);
          } catch (Exception e) { // sneaky checked exception
            // Log it and keep going.
            logger
                .get()

            mojos.put(Thread.currentThread(), mojoDescriptor);
            boolean aggregator = mojoDescriptor.isAggregator();
            acquiredAggregatorLock = aggregator ? aggregatorLock.writeLock() : aggregatorLock.readLock();
            acquiredProjectLock = getProjectLock(session);
            if (!acquiredAggregatorLock.tryLock()) {
                Thread owner = aggregatorLock.getOwner();

            // for proper cleanup, so we don't return early here
            Clock global = getClock(GLOBAL);
            global.start();
            lock.readLock().lock();
            try {
                // Process build steps in a logical order:
                // 1. Find steps that are not yet started (CREATED status)

	updateResourceMetrics(driveSubsystem, writesKBPerSec, writeKib/diffInSeconds, labels, false)

	rdAwait := 0.0
	if diffStats.ReadIOs > 0 {
		rdAwait = float64(diffStats.ReadTicks) / float64(diffStats.ReadIOs)
	}
	updateResourceMetrics(driveSubsystem, readsAwait, rdAwait, labels, false)

	wrAwait := 0.0
	if diffStats.WriteIOs > 0 {

	// - missing format.json (unformatted drive)
	// - format.json is valid but invalid 'uuid'
	if err = p.checkDiskStale(); err != nil {
		return ctx, done, err
	}

	// Disallow recursive tracking to avoid deadlocks.
	if ctx.Value(healthDiskCtxKey{}) != nil {
		done = p.updateStorageMetrics(s, paths...)
		return ctx, done, nil
	}

	if contextCanceled(ctx) {
		return ctx, done, ctx.Err()
	}

completely eliminate the IP allocation issue. More information [here](https://github.com/kubernetes/kubernetes/issues/21523#issuecomment-191498969)
  * Daemon becomes unresponsive (rarely) due to kernel deadlocks. More information [here](https://github.com/kubernetes/kubernetes/issues/21866#issuecomment-189492391)

### Provider-specific Notes

#### Various

   Core changes:

  * Change default clusterCIDRs from /16 to /14 allowing 1000 Node clusters by default.
  * Allow Debian Jessie on GCE.
  * Node problem detector addon pod detects and reports kernel deadlocks.
* OpenStack
  * Provider added.
* VSphere:
  * Provider updated.

## Previous Releases Included in v1.3.0

- [v1.3.0-beta.3](CHANGELOG.md#v130-beta3)
- [v1.3.0-beta.2](CHANGELOG.md#v130-beta2)

* Move config local to controllers in kube-controller-manager ([#72800](https://github.com/kubernetes/kubernetes/pull/72800), [@stewart-yu](https://github.com/stewart-yu))
* Fix some potential deadlocks and file descriptor leaking for inotify watches. ([#75376](https://github.com/kubernetes/kubernetes/pull/75376), [@cpuguy83](https://github.com/cpuguy83))