public NettyQueuesMetricsInitializer(final MetricFactory metricFactory, final EventLoopGroup elg) {
  if (metricFactory == null || elg == null) {
    return;
  }

  int index = 0;
  for (final EventExecutor eventExecutor : elg) {
    if (eventExecutor instanceof SingleThreadEventExecutor) {
      final SingleThreadEventExecutor singleExecutor = (SingleThreadEventExecutor) eventExecutor;
      metricFactory.registerGauge("GruffaloEventLoopGroup", "EventLoop-" + index, new Gauge<Integer>() {
        @Override
        public Integer getValue() {
          return singleExecutor.pendingTasks();
        }
      });

      index++;
    }
  }
}
 

private IntSupplier pendingTaskCounter(final EventLoopGroup eventLoopGroup) {
  return () ->
      StreamSupport.stream(eventLoopGroup.spliterator(), false)
          .filter(eventExecutor -> eventExecutor instanceof SingleThreadEventExecutor)
          .mapToInt(eventExecutor -> ((SingleThreadEventExecutor) eventExecutor).pendingTasks())
          .sum();
}
 

private IntSupplier pendingTaskCounter(final EventLoopGroup eventLoopGroup) {
  return () ->
      StreamSupport.stream(eventLoopGroup.spliterator(), false)
          .filter(eventExecutor -> eventExecutor instanceof SingleThreadEventExecutor)
          .mapToInt(eventExecutor -> ((SingleThreadEventExecutor) eventExecutor).pendingTasks())
          .sum();
}
 

@Override
protected void doRegister() throws Exception {
    // Check if both peer and parent are non-null because this channel was created by a LocalServerChannel.
    // This is needed as a peer may not be null also if a LocalChannel was connected before and
    // deregistered / registered later again.
    //
    // See https://github.com/netty/netty/issues/2400
    if (parent() != null) {
        // Store the peer in a local variable as it may be set to null if doClose() is called.
        // See https://github.com/netty/netty/issues/2144
        state = State.CONNECTED;
    }
    ((SingleThreadEventExecutor) eventLoop()).addShutdownHook(shutdownHook);
}
 

public static void registerQueueGauges(final MetricFactory factory, final EventLoopGroup elg, final String componentName) {
  if (factory == null || elg == null) {
    return;
  }

  int index = 0;
  for (final EventExecutor eventExecutor : elg) {
    if (eventExecutor instanceof SingleThreadEventExecutor) {
      final SingleThreadEventExecutor singleExecutor = (SingleThreadEventExecutor) eventExecutor;
      factory.registerGauge("EventLoopGroup-" + componentName, "EventLoop-" + index, singleExecutor::pendingTasks);

      index++;
    }
  }
}
 

@Override
protected void doDeregister() throws Exception {
    // Just remove the shutdownHook as this Channel may be closed later or registered to another EventLoop
    ((SingleThreadEventExecutor) eventLoop()).removeShutdownHook(shutdownHook);
}
 

@Override
protected void doRegister() throws Exception {
    ((SingleThreadEventExecutor) eventLoop()).addShutdownHook(shutdownHook);
}
 

@Override
protected void doDeregister() throws Exception {
    ((SingleThreadEventExecutor) eventLoop()).removeShutdownHook(shutdownHook);
}
 

@Override
protected void doDeregister() throws Exception {
    // Just remove the shutdownHook as this Channel may be closed later or registered to another EventLoop
    ((SingleThreadEventExecutor) eventLoop()).removeShutdownHook(shutdownHook);
}
 

@Override
protected void doRegister() throws Exception {
    ((SingleThreadEventExecutor) eventLoop()).addShutdownHook(shutdownHook);
}
 

@Override
protected void doDeregister() throws Exception {
    ((SingleThreadEventExecutor) eventLoop()).removeShutdownHook(shutdownHook);
}
 

@Override
protected void doDeregister() throws Exception {
    // Just remove the shutdownHook as this Channel may be closed later or registered to another EventLoop
    ((SingleThreadEventExecutor) eventLoop()).removeShutdownHook(shutdownHook);
}
 

@Override
protected void doRegister() throws Exception {
    ((SingleThreadEventExecutor) eventLoop()).addShutdownHook(shutdownHook);
}
 

@Override
protected void doDeregister() throws Exception {
    ((SingleThreadEventExecutor) eventLoop()).removeShutdownHook(shutdownHook);
}