Common Language Runtime

Common Language Runtime:

Lets see what actually CLR is and why it is so important –

1.The Common Language Runtime (CLR) is the virtual machine component of MS.NET framework and is responsible for managing the execution of MS.NET programs. It is a engine that runs the dotnet framework. Each and every process of a program which you write in DotNet is managed by CLR.

2.It works as a layer between Operating Systems and the applications written in MS.NET languages. Dotnet framework is platform dependant. It only executes on WINDOWS operating system. This CLR is acts as a layer between OS and our application to execute it.

3.The Common Language Runtime (CLR) 's Just In Time (JIT) compilation converts Intermediate Language (MSIL) to native code on demand at application run time.

üIn CLR there are different compilers for different languages.

üThese compilers converts the program code into MSIL (Mircosoft Intermediate Language) code. This MSIL is special language developed by the Microsoft which is understand by framework.

üNow in CLR there are JTI’s (Just In Time) compilers which converts this MSIL code into native code which is understand by machine and our program executes and we are able to see the output.

4.During the execution of the program ,the Common Language Runtime (CLR) manages memory, Thread execution, Garbage Collection (GC) , Exception Handling, Common Type System (CTS), code safety verifications, and other system services.

üCLR performs code management, code execution, memory management, memory allocation, memory de-allocation etc.

üAll processes from program compilation to execution will be handled by CLR.

üCLR also having one most important block called as Garbage Collector (GC) which runs simultaneously with your application. The task of this is, it frees the memory of unused object in the application. So that developer does not need to explicitly take care of memory management it can be done by CLR implicitly.

5.The Common Language Runtime (CLR) environment is also referred to as a managed environment, because during the execution of a program it also controls the interaction with the Operating System.

üCLR operates with the help of operating system and works as a layer between OS and dotnet framework that’s why dotnet is platform dependent it only works in WINDOWS Operating systems like XP, Windows 7, Server etc.

The code which is compiled by the CLR is called as Managed Code. If we are using any third party code which is called by Unmanaged code because that is not compiled by CLR.