模块加载部分：
core/module/FloodlightModuleLoader.java ?=> ?(396 – 403)
loadModulesFromList函数
<br /> for (IFloodlightModule module : moduleSet) {<br /> // init the module<br /> if (logger.isDebugEnabled()) {<br /> logger.debug("Initializing " + module.getClass().getCanonicalName());<br /> }<br /> module.init(floodlightModuleContext);<br /> }<br />
循环加载启动列表中的模块。其中module.init(floodlightModuleContext);执行
core/module/IFloodlightModule.java => (77 – 88)
Interface，转换到模块override的init函数。
<br /> void init(FloodlightModuleContext context) throws FloodlightModuleException;</p> <p>/**<br /> * This is a hook for each module to do its <em>external</em> initializations,<br /> * e.g.,register for callbacks or query for state in other modules<br /> *<br /> * It is expected that this function will not block and that modules that want<br /> * non-event driven CPU will spawn their own threads.<br /> *<br /> * @param context<br /> * @throws FloodlightModuleException<br /> */<br />
随后执行初始化完成的组件中的startUp函数。对于如下的事件绑定代码
<br /> floodlightProvider.addOFMessageListener(OFType.PACKET_IN,this);<br />
core/internal/Controller.java ==> (1451 – 1460)
<br /> //line 149 声明messageListeners实例<br /> protected ConcurrentMap<oftype,ListenerDispatcher<oftype,IOFMessageListener>><br /> messageListeners;<br /> //line 1446<br /> // ***************<br /> // IFloodlightProvider<br /> // ***************</p> <p>@Override<br /> public synchronized void addOFMessageListener(OFType type,<br /> IOFMessageListener listener) {<br /> ListenerDispatcher<oftype,IOFMessageListener> ldd =<br /> messageListeners.get(type); //从messageListeners中获取tpye事件的监听列表<br /> if (ldd == null) { //先检测对应事件列表ldd是否为空<br /> ldd = new ListenerDispatcher<oftype,IOFMessageListener>();<br /> messageListeners.put(type,ldd);<br /& 大专栏 ?FloodLight模块加载过程gt; }<br /> ldd.addListener(type,listener);<br /> }<br />
其中，ldd是事件注册列表（具体属性：listeners ArrayList
(id=187)）。ListenerDispatcher类的具体定义位置是core/util/ListenerDispatcher.java。Debug中，PacketIn事件的监听模块默认为：
<br /> elementData Object[10] (id=189)<br /> [0] LinkDiscoveryManager (id=193)<br /> [1] TopologyManager (id=200)<br /> [2] DeviceManagerImpl (id=207)<br /> [3] Firewall (id=213)<br /> [4] LoadBalancer (id=66)<br /> [5] Forwarding (id=218)<br /> [6] null<br /> ...<br />
事件加入函数
core/util/ListenerDispatcher.java ==> (71 – 107)
<br /> //line 38<br /> List<t> listeners = null;</p> <p>//line 71<br /> public void addListener(U type,T listener) {<br /> List<t> newlisteners = new ArrayList<t>();<br /> if (listeners != null) //listeners列表是否为空(当前监听者列表)<br /> newlisteners.addAll(listeners);//将原列表中信息复制进来</p> <p> newlisteners.add(listener);<br /> // Find nodes without outgoing edges<br /> List<t> terminals = new ArrayList<t>();<br /> for (T i : newlisteners) {<br /> boolean isterm = true;<br /> for (T j : newlisteners) {<br /> if (ispre(type,i,j)) {<br /> isterm = false;<br /> break;<br /> }<br /> }<br /> if (isterm) {<br /> terminals.add(i);<br /> }<br /> }</p> <p> if (terminals.size() == 0) {<br /> logger.error("No listener dependency solution: " +<br /> "No listeners without incoming dependencies");<br /> listeners = newlisteners;<br /> return;<br /> }</p> <p> // visit depth-first traversing in the opposite order from<br /> // the dependencies. Note we will not generally detect cycles<br /> HashSet<t> visited = new HashSet<t>();<br /> List<t> ordering = new ArrayList<t>();<br /> for (T term : terminals) {<br /> visit(newlisteners,type,visited,ordering,term);<br /> }<br /> listeners = ordering;<br /> }<br />
