if race.Enabled {
		if delta < 0 {
			// Synchronize decrements with Wait.
			race.ReleaseMerge(unsafe.Pointer(wg))
		}
		race.Disable()
		defer race.Enable()
	}
	state := wg.state.Add(uint64(delta) << 32)
	v := int32(state >> 32)
	w := uint32(state)
	if race.Enabled && delta > 0 && v == int32(delta) {
		// The first increment must be synchronized with Wait.
		// Need to model this as a read, because there can be

) : Closeable {
    override fun close() {
        // we synchronize access to all resources used by callbacks
        // in case there was still an event being dispatched at closing time.
        synchronized(writeContext) {
            unsafeWrite(null)
            writeContext.close()
        }
    }

    fun write(value: T, trace: PropertyTrace? = null) {
        synchronized(writeContext) {
            withPropertyTrace(trace) {

	// the acquire in profBuf.read synchronizes with *all* prior
	// setProfLabel operations, not just the most recent one. This
	// is important because profBuf.read will observe different
	// labels set by different setProfLabel operations on
	// different goroutines, so it needs to synchronize with all
	// of them (this wouldn't be an issue if we could synchronize
	// on &getg().labels since we would synchronize with each

//
// In the terminology of [the Go memory model],
// the n'th call to [RWMutex.Unlock] “synchronizes before” the m'th call to Lock
// for any n < m, just as for [Mutex].
// For any call to RLock, there exists an n such that
// the n'th call to Unlock “synchronizes before” that call to RLock,
// and the corresponding call to [RWMutex.RUnlock] “synchronizes before”
// the n+1'th call to Lock.
//
// [the Go memory model]: https://go.dev/ref/mem

    startTask();
    try {
      command.run();
    } finally {
      endTask();
    }
  }

  @Override
  public boolean isShutdown() {
    synchronized (lock) {
      return shutdown;
    }
  }

  @Override
  public void shutdown() {
    synchronized (lock) {
      shutdown = true;
      if (runningTasks == 0) {
        lock.notifyAll();
      }
    }
  }

    startTask();
    try {
      command.run();
    } finally {
      endTask();
    }
  }

  @Override
  public boolean isShutdown() {
    synchronized (lock) {
      return shutdown;
    }
  }

  @Override
  public void shutdown() {
    synchronized (lock) {
      shutdown = true;
      if (runningTasks == 0) {
        lock.notifyAll();
      }
    }
  }

            }
            return actor;
        }
    }

    private void stopped(NonBlockingActor actor) {
        synchronized (lock) {
            nonBlockingActors.values().remove(actor);
        }
    }

    private void stopped(BlockingActor actor) {
        synchronized (lock) {
            blockingActors.values().remove(actor);
        }
    }

    private class BlockingActor implements Actor {

            }
        }
    }

    @Override
    public void close() {
        synchronized (lock) {
            // Allow threads to read anything still buffered
            closed = true;
            lock.notifyAll();
        }
    }

    public void received(byte[] bytes) {
        synchronized (lock) {
            if (!waiting) {
                throw new IllegalStateException();
            }

    override fun scopeFor(classLoader: ClassLoader?): Pair<ClassLoaderScopeSpec, ClassLoaderRole>? {
        synchronized(lock) {
            return loaders[classLoader]
        }
    }

    override fun childScopeCreated(parentId: ClassLoaderScopeId, childId: ClassLoaderScopeId, origin: ClassLoaderScopeOrigin?) {
        synchronized(lock) {
            if (scopeSpecs.containsKey(childId)) {
                // scope is being reused

        synchronized (instanceLock) {
            stopActions = stopActions.plus(stopAction);
        }
    }

    @Override
    protected Value<? extends T> calculateOwnValue(ValueConsumer consumer) {
        return Value.of(getInstance());
    }

    private T getInstance() {
        listener.beforeGet(this);
        synchronized (instanceLock) {