I keep seeing "bootstrapping" mentioned in discussions of application development. It seems both widespread and important, but I've yet to come across even a poor explanation of what bootstrapping actually is; rather, it seems as though everyone is just supposed to know what it means. I don't, though. Near as I can figure, it has something to do with initialization tasks required of an application upon launch, but I could be completely wrong about that. Can anyone help me to understand this idea?
当前回答
恕我冒昧,没有比第一个编译器是如何编写的更好的解释了?
现在,操作系统加载是最常见的过程,称为引导
其他回答
I belong to the generation who flipped switches to enter a boot program. In the early 1980s, I worked on a microcomputer called Micro-78, developed by Electronics Corporation of India Ltd (ECIL). It was a sort of clone of Altair 8800. I distinctly remember what happens when a small boot program was entered using the toggle switches and executed by pressing a button. The program reads a second boot program contained in the 1st track of the floppy disk and overwrites it on itself in such a way that the second boot program starts executing to load a disk operating system. I think the term "bootstrap" refers to this process of the first boot program reading and overwriting the second boot program on itself, in a way "pulling itself up" with the additional functionality of the second boot program. That may be the origin of the original meaning of "the bootstrap program".
为了完整起见,它也是统计学中一个相当重要的(相对较新的)方法,它使用重采样/模拟从样本中推断总体属性。它在维基百科上有一篇关于自我引导(统计)的长篇文章。
术语“自举”通常适用于系统依赖自身启动的情况,有点像鸡和蛋的问题。
例如:
如何编译用C编写的C编译器? 如果操作系统还没有运行,如何启动操作系统初始化进程? 如何启动一个分布式(点对点)系统,在这个系统中,客户端依赖于它们当前已知的对等点来查找系统中的新对等点?
在这种情况下,bootstrapping指的是一种打破循环依赖关系的方法,通常借助外部实体的帮助。
您可以使用另一个C编译器来编译(引导)您自己的编译器,然后您可以使用它来重新编译自己 您使用一段单独的代码来设置初始进程,而不依赖于操作系统提供的任何函数 您使用硬编码的初始对等体列表或提供对等体列表的硬编码跟踪器URL
etc.
引导文件负责加载主文件的内容。它是主文件的包装器。这样,如果由于某种原因加载文件不成功,我们就可以捕获错误。
在一些web框架中有一个引导的例子。你调用index.php (bootstrapper),然后它加载框架的助手、模型、配置,然后加载控制器并将控制权传递给它。
正如您所看到的,这是一个启动大进程的简单文件。