void AsyncAppender::dispatch()

in src/main/cpp/asyncappender.cpp [525:606]
78 lines of code
17 McCabe index (conditional complexity)

void AsyncAppender::dispatch()
{
	size_t discardCount = 0;
	std::vector<size_t> pendingCountHistogram(priv->bufferSize, 0);
	bool isActive = true;

	while (isActive)
	{
		Pool p;
		LoggingEventList events;
		events.reserve(priv->bufferSize);
		for (int count = 0; count < 2 && priv->dispatchedCount == priv->commitCount; ++count)
			std::this_thread::yield(); // Wait a bit
		if (priv->dispatchedCount == priv->commitCount)
		{
			std::unique_lock<std::mutex> lock(priv->bufferMutex);
			priv->bufferNotEmpty.wait(lock, [this]() -> bool
				{ return 0 < priv->blockedCount || priv->dispatchedCount != priv->commitCount || priv->closed; }
			);
		}
		isActive = !priv->isClosed();

		while (events.size() < priv->bufferSize && priv->dispatchedCount != priv->commitCount)
		{
			auto index = priv->dispatchedCount % priv->buffer.size();
			const auto& data = priv->buffer[index];
			events.push_back(data.event);
			if (data.pendingCount < pendingCountHistogram.size())
				++pendingCountHistogram[data.pendingCount];
			++priv->dispatchedCount;
		}
		priv->bufferNotFull.notify_all();
		{
			std::lock_guard<std::mutex> lock(priv->bufferMutex);
			for (auto discardItem : priv->discardMap)
			{
				events.push_back(discardItem.second.createEvent(p));
				discardCount += discardItem.second.getCount();
			}
			priv->discardMap.clear();
		}

		for (auto item : events)
		{
			try
			{
				priv->appenders.appendLoopOnAppenders(item, p);
			}
			catch (std::exception& ex)
			{
				if (!priv->isClosed())
				{
					priv->errorHandler->error(LOG4CXX_STR("async dispatcher"), ex, 0, item);
					isActive = false;
				}
			}
			catch (...)
			{
				if (!priv->isClosed())
				{
					priv->errorHandler->error(LOG4CXX_STR("async dispatcher"));
					isActive = false;
				}
			}
		}
	}
	if (LogLog::isDebugEnabled())
	{
		Pool p;
		LogString msg(LOG4CXX_STR("AsyncAppender"));
		msg += LOG4CXX_STR(" discardCount ");
		StringHelper::toString(discardCount, p, msg);
		msg += LOG4CXX_STR(" pendingCountHistogram");
		for (auto item : pendingCountHistogram)
		{
			msg += logchar(' ');
			StringHelper::toString(item, p, msg);
		}
		LogLog::debug(msg);
	}

}