1、创建全局定时器，bool CCDirector::init(void)函数中，，调用
// schedulerm_pScheduler = new CCScheduler();2、在每帧渲染前，都会调用CCScheduler的update方法// Draw the Scenevoid CCDirector::drawScene(void){// calculate "global" dtcalculateDeltaTime();//tick before glClear: issue #533if (! m_bPaused) //调用定时器的update方法{m_pScheduler->update(m_fDeltaTime);}}3、CCScheduler中有几个很重要的成员变量，//每帧都要调用的定时器struct _listEntry *m_pUpdatesNegList;// list of priority < 0 //存放priority < 0的Update，优先级最高struct _listEntry *m_pUpdates0List;// list priority == 0 //存放priority == 0的Updatestruct _listEntry *m_pUpdatesPosList;// list priority > 0//存放priority > 0的Update，优先级最低//方便快速查找struct _hashUpdateEntry *m_pHashForUpdates; // hash used to fetch quickly the list entries for pause,delete,etc// Used for "selectors with interval"，设置了时间间隔的定时器列表struct _hashSelectorEntry *m_pHashForTimers; //4、CCScheduler的update函数很大，主要是几个循环。
// main loopvoid CCScheduler::update(float dt){m_bUpdateHashLocked = true;if (m_fTimeScale != 1.0f){dt *= m_fTimeScale;}// Iterate over all the Updates' selectorstListEntry *pEntry, *pTmp;// updates with priority < 0 优先调用// pEntry->target->update(dt) 调用target的update方法，例继承与CCNode的类//可以重写 CCNode的 update方法/** Update method will be called automatically every frame if "scheduleUpdate" is called, and the node is "live"*///virtual void update(float delta);DL_FOREACH_SAFE(m_pUpdatesNegList, pEntry, pTmp){if ((! pEntry->paused) && (! pEntry->markedForDeletion)){pEntry->target->update(dt);}}// updates with priority == 0DL_FOREACH_SAFE(m_pUpdates0List, pEntry, pTmp){if ((! pEntry->paused) && (! pEntry->markedForDeletion)){pEntry->target->update(dt);}}// updates with priority > 0DL_FOREACH_SAFE(m_pUpdatesPosList, pEntry, pTmp){if ((! pEntry->paused) && (! pEntry->markedForDeletion)){pEntry->target->update(dt);}}// Iterate over all the custom selectors//遍历有时间间隔的定时器列表，调用相应的方法for (tHashTimerEntry *elt = m_pHashForTimers; elt != NULL; ){m_pCurrentTarget = elt;m_bCurrentTargetSalvaged = false;if (! m_pCurrentTarget->paused){// The 'timers' array may change while inside this loopfor (elt->timerIndex = 0; elt->timerIndex < elt->timers->num; ++(elt->timerIndex)){elt->currentTimer = (CCTimer*)(elt->timers->arr[elt->timerIndex]);elt->currentTimerSalvaged = false;elt->currentTimer->update(dt);if (elt->currentTimerSalvaged){// The currentTimer told the remove itself. To prevent the timer from// accidentally deallocating itself before finishing its step, we retained// it. Now that step is done, it's safe to release it.elt->currentTimer->release();}elt->currentTimer = NULL;}}// elt, at this moment, is still valid// so it is safe to ask this here (issue #490)elt = (tHashTimerEntry *)elt->hh.next;// only delete currentTarget if no actions were scheduled during the cycle (issue #481)if (m_bCurrentTargetSalvaged && m_pCurrentTarget->timers->num == 0){removeHashElement(m_pCurrentTarget);}}// Iterate over all the script callbacks//遍历针对脚本的定时器列表if (m_pScriptHandlerEntries){for (int i = m_pScriptHandlerEntries->count() – 1; i >= 0; i–){CCSchedulerScriptHandlerEntry* pEntry = static_cast<CCSchedulerScriptHandlerEntry*>(m_pScriptHandlerEntries->objectAtIndex(i));if (pEntry->isMarkedForDeletion()){m_pScriptHandlerEntries->removeObjectAtIndex(i);}else if (!pEntry->isPaused()){pEntry->getTimer()->update(dt);}}}// delete all updates that are marked for deletion// updates with priority < 0//删除一些没用定时器DL_FOREACH_SAFE(m_pUpdatesNegList, pEntry, pTmp){if (pEntry->markedForDeletion){this->removeUpdateFromHash(pEntry);}}// updates with priority == 0DL_FOREACH_SAFE(m_pUpdates0List, pEntry, pTmp){if (pEntry->markedForDeletion){this->removeUpdateFromHash(pEntry);}}// updates with priority > 0DL_FOREACH_SAFE(m_pUpdatesPosList, pEntry, pTmp){if (pEntry->markedForDeletion){this->removeUpdateFromHash(pEntry);}}m_bUpdateHashLocked = false;m_pCurrentTarget = NULL;}
当花儿枯萎的时候，就是它生命终结的时候，
