public void onEvent(Event event) throws Throwable {
    try {
        /*
         * event过滤；针对单个listener，只处理top的事件
         */
        /** -------- **/
        /*
         * 初始化Tracer开启上下文追踪[基于TTL，支持多线程上下文传递]
         */
        /** -------- **/
        /*
         * 执行基础过滤
         */
        /** -------- **/
        /*
         * 执行采样计算
         */
        /** -------- **/
        /*
         * processor filter
         */
        /** -------- **/
        /*
         * 分发事件处理
         */
    } catch (ProcessControlException pe) {
        /*
         * sandbox流程干预
         */
    } catch (Throwable throwable) {
    	 /*
    	  * 统计异常
    	  */
    } finally {
        /*
         * 清理上下文
         */
    }
}

public void doMock(BeforeEvent event, Boolean entrance, InvokeType type) throws ProcessControlException {
    /*
     * 获取回放上下文
     */
    RepeatContext context = RepeatCache.getRepeatContext(Tracer.getTraceId());
    /*
     * mock执行条件
     */
    if (!skipMock(event, entrance, context) && context != null && context.getMeta().isMock()) {
        try {
            /*
             * 构建mock请求
             */
            final MockRequest request = MockRequest.builder()
                    ...
                    .build();
            /*
             * 执行mock动作
             */
            final MockResponse mr = StrategyProvider.instance().provide(context.getMeta().getStrategyType()).execute(request);
            /*
             * 处理策略推荐结果
             */
            switch (mr.action) {
  					...
            }
        } catch (ProcessControlException pce) {
            throw pce;
        } catch (Throwable throwable) {
            ProcessControlException.throwThrowsImmediately(new RepeatException("unexpected code snippet here.", throwable));
        }
    }
}