if (sharedInstance != null && args == null) {// 这里被我删除了一些spring  的log// 处理一下 factory bean 的情况、包括从 factory beans 的缓存中获取、或者重新调用 factory bean 的 get bean 方法 包括一些回调bean = getObjectForBeanInstance(sharedInstance, name, beanName, null);
} else {// 从 上面的 getSingleton 拿不到对象的bean 、说明这个bean的scope 要么不是 singleton 要这个bean是singleton 但是没有初始化一句//  因为 Spring 只解决单例模式下得循环依赖，在原型模式下如果存在循环依赖则会抛出异常// 这里的循环依赖检查使用的 是 threadLocal 因为 prototype 类型的只是if (isPrototypeCurrentlyInCreation(beanName)) {throw new BeanCurrentlyInCreationException(beanName);}// 如果容器中没有找到，则从父类容器中加载BeanFactory parentBeanFactory = getParentBeanFactory();// parentBeanFactory 不为空且 beanDefinitionMap 中不存该 name 的 BeanDefinitionif (parentBeanFactory != null && !containsBeanDefinition(beanName)) {// Not found -> check parent.// 这里只是找出他的真正的beanName、并没有去掉 factory bean 的前缀String nameToLookup = originalBeanName(name);if (parentBeanFactory instanceof AbstractBeanFactory) {return ((AbstractBeanFactory) parentBeanFactory).doGetBean(nameToLookup, requiredType, args, typeCheckOnly);} else if (args != null) {// Delegation to parent with explicit args.return (T) parentBeanFactory.getBean(nameToLookup, args);} else if (requiredType != null) {// No args -> delegate to standard getBean method.return parentBeanFactory.getBean(nameToLookup, requiredType);} else {return (T) parentBeanFactory.getBean(nameToLookup);}}......................
}

protected boolean isPrototypeCurrentlyInCreation(String beanName) {// prototypesCurrentlyInCreation 是一个 threadLocalObject curVal = this.prototypesCurrentlyInCreation.get();return (curVal != null &&(curVal.equals(beanName) || (curVal instanceof Set && ((Set<?>) curVal).contains(beanName))));
}

protected void beforePrototypeCreation(String beanName) {Object curVal = this.prototypesCurrentlyInCreation.get();if (curVal == null) {this.prototypesCurrentlyInCreation.set(beanName);} else if (curVal instanceof String) {Set<String> beanNameSet = new HashSet<>(2);beanNameSet.add((String) curVal);beanNameSet.add(beanName);this.prototypesCurrentlyInCreation.set(beanNameSet);} else {Set<String> beanNameSet = (Set<String>) curVal;beanNameSet.add(beanName);}
}

protected void afterPrototypeCreation(String beanName) {Object curVal = this.prototypesCurrentlyInCreation.get();if (curVal instanceof String) {this.prototypesCurrentlyInCreation.remove();} else if (curVal instanceof Set) {Set<String> beanNameSet = (Set<String>) curVal;beanNameSet.remove(beanName);if (beanNameSet.isEmpty()) {this.prototypesCurrentlyInCreation.remove();}}}

// 如果不是仅仅做类型检查则是创建bean，标记这个bean 已经创建了或者将要被创建
if (!typeCheckOnly) {markBeanAsCreated(beanName);
}try {//  从容器中获取 beanName 相应的 GenericBeanDefinition，并将其转换为 RootBeanDefinitionfinal RootBeanDefinition mbd = getMergedLocalBeanDefinition(beanName);//  检查给定的合并的 BeanDefinitioncheckMergedBeanDefinition(mbd, beanName, args);// Guarantee initialization of beans that the current bean depends on.// 处理所依赖的 beanString[] dependsOn = mbd.getDependsOn();if (dependsOn != null) {for (String dep : dependsOn) {// 如果是循环依赖if (isDependent(beanName, dep)) {throw new BeanCreationException(mbd.getResourceDescription(), beanName,"Circular depends-on relationship between '" + beanName + "' and '" + dep + "'");}// 注册registerDependentBean(dep, beanName);try {// 看看我依赖的大佬好了没getBean(dep);} catch (NoSuchBeanDefinitionException ex) {throw new BeanCreationException(mbd.getResourceDescription(), beanName,"'" + beanName + "' depends on missing bean '" + dep + "'", ex);}}}............

protected boolean isDependent(String beanName, String dependentBeanName) {synchronized (this.dependentBeanMap) {return isDependent(beanName, dependentBeanName, null);}
}private boolean isDependent(String beanName, String dependentBeanName, @Nullable Set<String> alreadySeen) {if (alreadySeen != null && alreadySeen.contains(beanName)) {return false;}String canonicalName = canonicalName(beanName);// 找出依赖这个beanName的集合Set<String> dependentBeans = this.dependentBeanMap.get(canonicalName);// 没有人依赖这个beanNameif (dependentBeans == null) {return false;}// 哦嚯、beanName 依赖的 bean、也依赖着beanName、完蛋if (dependentBeans.contains(dependentBeanName)) {return true;}// 看看依赖 beanName 的 其他依赖、有没有被dependentBeanName 依赖// A 想依赖F、BCDE 依赖着A、那么我们现在来到这一步、已经确定了F不依赖A、那么我们要看看F是否依赖BCDE、如果依赖、那么就是循环依赖了for (String transitiveDependency : dependentBeans) {if (alreadySeen == null) {alreadySeen = new HashSet<>();}alreadySeen.add(beanName);if (isDependent(transitiveDependency, dependentBeanName, alreadySeen)) {return true;}}return false;
}

key 为被依赖者 value 为依赖者集合
beanB ---> beanA
beanC ---> beanA
key 为依赖者，value 为被依赖者集合
beanA ---> beanB,beanC

public void registerDependentBean(String beanName, String dependentBeanName) {String canonicalName = canonicalName(beanName);// 在这个里面加上 这个依赖我的人synchronized (this.dependentBeanMap) {Set<String> dependentBeans =this.dependentBeanMap.computeIfAbsent(canonicalName, k -> new LinkedHashSet<>(8));if (!dependentBeans.add(dependentBeanName)) {return;}}// 在这里将我依赖的 那个大佬放进去我依赖的列表中synchronized (this.dependenciesForBeanMap) {Set<String> dependenciesForBean =this.dependenciesForBeanMap.computeIfAbsent(dependentBeanName, k -> new LinkedHashSet<>(8));dependenciesForBean.add(canonicalName);}}

getBean(dep);