Application Domains Common Language Specification CLS
3.5 Application Domains
Application domains are to the CLR what processes are to an operating system. It may be surprising to note that the CLR can run multiple .NET applications within a single process, without any contention or security difficulties. Because the CLR has complete control over loading and executing programs, and because of the presence of type information, the CLR guarantees that .NET applications cannot read or write each others memory, even when running in the same process. Because there is less performance overhead in switching between application domains than in switching between processes, this provides a performance gain. This is especially beneficial to web applications running in Internet Information Services IIS, where scalability is an issue.3.6 Common Language Specification CLS
The CLI defines a runtime that is capable of supporting most, if not all, of the features found in modern programming languages. It is not intended that all languages that target the CLR will support all CLR features. This could cause problems when components written in different languages attempt to interoperate. The CLI therefore defines a subset of features that are considered compatible across language boundaries. This subset is called the Common Language Specification CLS. Vendors creating components for use by others need to ensure that all externally visible constructs e.g., public types, public and protected methods, parameters on public and protected methods, etc. are CLS-compliant. This ensures that their components will be usable within a broad array of languages, including Visual Basic .NET. Developers authoring components in Visual Basic .NET have an easy job because all Visual Basic .NET code is CLS-compliant unless the developer explicitly exposes a public or protected type member or method parameter that is of a non-CLS-compliant type. 117 Because Visual Basic .NET automatically generates CLS-compliant components, this book does not describe the CLS rules. However, to give you a sense of the kind of thing that the CLS specifies, consider that some languages support a feature called operator overloading . This allows the developer to specify actions that should be taken if the standard operator symbols + , - , , , = , etc. are used on user-defined classes. Because it is not reasonable to expect that all languages should implement such a feature, the CLS has a rule about it. The rule states that if a CLS-compliant component has public types that provide overloaded operators, those types must provide access to that functionality in another way as well usually by providing a public method that performs the same operation.3.7 Intermediate Language IL and Just-In-Time JIT Compilation
Parts
» VB.NET - (O'Reilly) Programming Visual Basic NET
» What Is the Microsoft .NET Framework?
» hello, world An Example Visual Basic .NET Program
» Hello, Windows An Example Visual Basic .NET Program
» Hello, Browser An Example Visual Basic .NET Program
» Source Files Identifiers The Visual Basic .NET Language
» Numeric Literals String Literals Character Literals
» Date Literals Boolean Literals Nothing Summary of Literal Formats
» Custom Types Collections Types
» The Namespace Statement The Imports Statement
» Symbolic Constants Scope The Visual Basic .NET Language
» Access Modifiers Assignment The Visual Basic .NET Language
» Unary Operators Arithmetic Operators
» Relational Operators Operators and Expressions
» String-Concatenation Operators Bitwise Operators
» Logical Operators Operator Precedence
» Call Exit Branching Statements
» Goto If RaiseEvent Branching Statements
» Return Select Case Branching Statements
» For Each Iteration Statements
» Object Instantiation and New Constructors
» Handling Events Inheritance Classes
» Passing arrays as parameters
» Variable-length parameter lists Main method
» Implementing interface methods Overriding inherited methods
» Overloading Overloading inherited methods
» The MyBase Keyword Nested Classes Destructors
» Interfaces The Visual Basic .NET Language
» Enumerations The Visual Basic .NET Language
» Exceptions The Visual Basic .NET Language
» Delegates The Visual Basic .NET Language
» Using Events and Delegates Together
» Creating Custom Attributes Attributes
» Standard Modules Conditional Compilation
» Summary The Visual Basic .NET Language
» Common Language Infrastructure CLI and Common Language Runtime CLR
» Global Assembly Cache GAC Comparison of Assemblies, Modules, and Namespaces
» Application Domains Common Language Specification CLS
» Intermediate Language IL and Just-In-Time JIT Compilation Metadata
» Finalize Memory Management and Garbage Collection
» Dispose Memory Management and Garbage Collection
» A Brief Tour of the .NET Framework Namespaces
» Configuration File Format Configuration
» Configuration Section Groups The appSettings Section
» Adding event handlers Creating a Form in Code
» Handling Form Events Windows Forms I: Developing Desktop Applications
» Relationships Between Forms Windows Forms I: Developing Desktop Applications
» Merging Menus MDI Applications
» Detecting MDI Child Window Activation
» Component Attributes Windows Forms I: Developing Desktop Applications
» The Graphics Class 2-D Graphics Programming with GDI+
» The Pen Class 2-D Graphics Programming with GDI+
» The Brush Class 2-D Graphics Programming with GDI+
» System colors The Color Structure
» Alpha Blending 2-D Graphics Programming with GDI+
» Antialiasing 2-D Graphics Programming with GDI+
» The PrintPageEventArgs Class Printing
» The OnBeginPrint and OnEndPrint Methods Choosing a Printer
» The PageSettings Class Printing
» The PrinterSettings Class Printing
» Page Setup Dialog Box Print Preview
» Summary Windows Forms I: Developing Desktop Applications
» The Button Class The CheckBox Class The ComboBox Class
» The DateTimePicker Class The GroupBox Class The ImageList Class
» The Label Class The LinkLabel Class
» The ListBox Class Common Controls and Components
» The ListBox.ObjectCollection Class
» The ListView Class Common Controls and Components
» The MonthCalendar Class Common Controls and Components
» The Panel Class The PictureBox Class
» The RadioButton Class Common Controls and Components
» The TextBox Class The Timer Class
» Other Controls and Components
» Control Events Windows Forms II: Controls, Common Dialog Boxes, and Menus
» The Anchor Property Form and Control Layout
» Controlling dock order The Dock Property
» The Splitter control The Dock Property
» ColorDialog FontDialog OpenFileDialog Common Dialog Boxes
» PageSetupDialog PrintDialog PrintPreviewDialog SaveFileDialog
» Adding Menus in the Visual Studio .NET Windows Forms Designer
» Programmatically Creating Menus Menus
» Building Controls from Other Controls
» Building Controls That Draw Themselves Building Nonrectangular Controls
» Summary Windows Forms II: Controls, Common Dialog Boxes, and Menus
» Setting control properties using attributes Adding event handlers
» AutoEventWireup Handling Page Events
» The Button control Web Controls
» The CheckBox control The DropDownList control
» The Image control The Label control
» The ListBox control Web Controls
» The RadioButton control Web Controls
» The Table control Web Controls
» The TextBox control Web Controls
» Other web controls Web Controls
» HTML Controls Handling Control Events
» Programmatically Instantiating Controls More About Server Controls
» More About Validation-Control Tag Attributes
» Using Validation-Control Properties Providing a Summary View of Validation Failures
» Performing Custom Validation Adding Validation
» Using Directives to Modify Web Page Compilation
» The Server Object ASP.NET Objects: Interacting with the Framework
» The Application Object The Session Object The Cache Object The Request Object
» The Response Object ASP.NET Objects: Interacting with the Framework
» Discovering Browser Capabilities ASP.NET and Web Forms: Developing Browser-Based Applications
» The Session Object Maintaining State
» The Application Object Maintaining State
» Session and Application Startup and Shutdown global.asax Compiles to a Class
» Adding Global Objects Application-Level Code and global.asax
» ASP.NET authorization Authorization
» Windows NTFS authorization Code-access authorization
» IUSR_ComputerName Impersonation Accessing Network Resources
» User Controls Designing Custom Controls
» Creating a custom server control using Visual Studio .NET
» Creating a custom server control in code Using a custom server control in Visual Studio .NET
» Summary ASP.NET and Web Forms: Developing Browser-Based Applications
» The WebService Attribute The WebMethod Attribute
» Testing a Web Service with a Browser
» Consuming a Web Service in Visual Studio .NET
» Consuming a Web Service in Notepad
» Synchronous Versus Asynchronous Calls
» Web-Service Descriptions Web-Service Discovery
» Limitations of Web Services Summary
» A Brief History of Universal Data Access Managed Providers
» Connecting to a SQL Server Database
» Connecting to an OLE DB Data Source
» The DataSet Class Finding Tables
» Finding Column Values Finding Column Definitions Changing, Adding, and Deleting Rows
» Writing Updates Back to the Data Source
» Relations Between DataTables in a DataSet
» The DataSets XML Capabilities
» Binding a DataSet to a Windows Forms DataGrid
» Binding a DataSet to a Web Forms DataGrid
» Typed DataSets ADO.NET: Developing Database Applications
» Reading Data Using a DataReader
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