使用mqtt协议传输音视频，经历过内存泄漏和cpu loading过大的问题。现在遇到一个bus error：

[1]+  Bus error (core dumped)    ./mqtt-test

有遇到过吗？分析core文件，定位到函数调用：MQTTAsync_processCommand

仅在线程MQTTAsync_sendThread中调用，

线程源码：

static thread_return_type WINAPI MQTTAsync_sendThread(void* n)
{
	FUNC_ENTRY;
	MQTTAsync_lock_mutex(mqttasync_mutex);
	sendThread_state = RUNNING;
	sendThread_id = Thread_getid();
	MQTTAsync_unlock_mutex(mqttasync_mutex);
	while (!tostop)
	{
		int rc;

		while (commands->count > 0)
		{
			if (MQTTAsync_processCommand() == 0)
				break;  /* no commands were processed, so go into a wait */
		}
#if !defined(WIN32) && !defined(WIN64)
		if ((rc = Thread_wait_cond(send_cond, 1)) != 0 && rc != ETIMEDOUT)
			Log(LOG_ERROR, -1, "Error %d waiting for condition variable", rc);
#else
		if ((rc = Thread_wait_sem(send_sem, 1000)) != 0 && rc != ETIMEDOUT)
			Log(LOG_ERROR, -1, "Error %d waiting for semaphore", rc);
#endif

		MQTTAsync_checkTimeouts();
	}
	sendThread_state = STOPPING;
	MQTTAsync_lock_mutex(mqttasync_mutex);
	sendThread_state = STOPPED;
	sendThread_id = 0;
	MQTTAsync_unlock_mutex(mqttasync_mutex);
	FUNC_EXIT;
	return 0;
}