Introduction to two important innovations in the win xp system

Some system features of Windows XP don't know how much you know. There are a lot of important features. Maybe we don't know about it, but they are really important. Let's introduce the innovative isolation component of Windows XP (Isolated). Components) and side-by-side sharing.

An important innovation in Windows XP is the introduction of Isolated Components and side-by-side sharing. As a solution to the DLL conflict problem that often occurs in Windows, Microsoft strongly recommends that applications use component isolation and side-by-side sharing techniques to solve problems with DLL calls. Microsoft used parallel shared processing in ComCtl version 6, proving that isolation components and side-by-side sharing are the future direction of Windows. In this section, let's take a look at some of the Windows XP isolation components and the overall technical framework for side-by-side sharing.

In the use of isolation components and side-by-side sharing mode, many different versions of a component are installed in the system at the same time. Note that it is "also" installed in the system. In the original Windows, a component or a DLL in the system can only have one version, so when installing the application, we often see a dialog box like this: "xxxx.dll to be installed is more than the original one in the system. Old, is it covered or reserved?". This question is really not a good question, because the old DLL is installed, the application that used the new DLL may not work properly; if it is not installed, the new application may not work properly. This is really a dilemma.

Windows XP uses isolation components and side-by-side sharing to better solve this problem. Since there can be multiple versions of a DLL or component in the system, the application can choose to use a version of the component that was rigorously tested at the time of design or development. This avoids unpredictable errors that can result from applications being forced to call different versions of DLLs or components.

In Windows XP, quarantine components and side-by-side sharing are primarily implemented through a manifest. Through the program manifest, an application completely defines the version of the DLL or component that needs to be called at runtime. Windows XP relies on the program manifest to ensure that an application's upgrade or deletion in the system does not affect the DLLs or components that other programs need to use. So we see that isolation components and side-by-side sharing ensure system security and application security.

"manifest" is an XML file that contains all the information about a program installation and assembly, such as metadata required for all program bundles and installations (metadata refers to the basics required by the program) DLL calls, component support, interface definitions, etc.), such as COM classes, interface definitions, and DLL library definitions. There are two types of manifest files: an application manifest file that describes all the metadata required by the application; an assembly manifest file that describes the installation of individual components.

An application can clearly indicate in the program listing how all the program components it contains are installed in the system. An application contains many basic elements, such as interface definitions, help files, different versions of components, system configuration information, and more. All of these elements can be divided into two categories according to the program list: public and private. Public elements can be used by other applications installed on the computer, they are installed in the WinSxS directory of Windows XP. Private elements can only be used by applications that contain them, and are installed in a directory unique to the application.

I don't know if you have any impressions on these two functions or they are usually useful, but these features are worth paying attention to anyway, although many features are things we have not covered. But these are the keys to understanding the system.