Object lifetime Temporary object lifetime Storage reuse Access outside of lifetime Every object has a lifetime, which is a runtime property: for any object, there is a moment during the execution of a program when its lifetime begins, and there is a…

"free store" VS "heap" 当我问你C++的内存布局时,你大概会回答: "在C++中,内存区分为5个区,分别是堆.栈.自由存储区.全局/静态存储区.常量存储区". 如果我接着问你自由存储区与堆有什么区别,你或许这样回答: "malloc在堆上分配的内存块,使用free释放内存,而new所申请的内存则是在自由存储区上,使用delete来释放." 这样听起来似乎也没错,但如果我接着问: 自由存储区与堆是两块不同的…

1. free store VS heap free store (自由存储区)和 heap (堆),在C/C++中经常会遇到.他们是否有区别呢? 偶最早发现这两个概念性问题是在<Exceptional C++>一书中. 其中提到C++中使用new分配所得的内存是分配在 freestore 上,而C 风格的内存分配 malloc 分配所得的内存是在 heap 上. 额.这个有什么区别呢? 通过在 Google 的搜索,所得的中文资料相当少,英文的倒是不少,而且不少还有争议性质. 不过部分观点是…

最近看到了很多优秀的文章,包括<Why mobile web apps are slow>,实在忍不住翻译出来跟大家分享.这篇文章通过大量的实验和参考文献向我们说明移动应用开发所遇到的问题,基本的观点可以总结为:移动平台的编程环境是一种资源受限(主要是CPU和内存)的环境,在这样的环境下编程,程序员不得不考虑如何高效地利用资源,这些问题不是仅仅靠一些高级语言特性(如垃圾回收)就能够解决的.因为这些高级语言特性在尝试解决一个问题的同时,往往又会引入其它的问题. 也就是说,无论编程语言发展到多么高…

Usage There are two different ways to use winston: directly via the default logger, or by instantiating your own Logger. The former is merely intended to be a convenient shared logger to use throughout your application if you so choose. 有两种不同的方式使用win…

AutoReleasePool autoreleasepool并不是总是被auto 创建,然后自动维护应用创建的对象. 自动创建的情况如下: 1. 使用NSThread的detachNewThreadSelector:toTarget:withObject:方法创建新线程时,新线程自动带有autoreleasepool. 2. Main thread of Cocoa Application 以下情况需要开发者创建: 1. 在使用Dispatch Queue时, 虽然其Pool中每个thread…

1.what is the main disadvantage of garbage collection? Typically, garbage collection has certain disadvantages, including consuming additional resources, performance impacts, possible stalls in program execution, and incompatibility with manual resou…

https://msdn.microsoft.com/en-US/library/aa970850(v=vs.100).aspx In applications, it is possible that handlers that are attached to event sources will not be destroyed in coordination with the listener object that attached the handler to the source.…

Using Sessions and Session Persistence The following sections describe how to set up and use sessions and session persistence: Overview of HTTP Sessions Setting Up Session Management Configuring Session Persistence Using URL Rewriting Instead of Cook…

A while back, I posted a list of ASP.NET Interview Questions. Conventional wisdom was split, with about half the folks saying I was nuts and that it was a list of trivia. The others said basically "Ya, those are good. I'd probably have to look a few…