AppDomains Created by the CLR

CLR creates 3 Application Domain before exceuting the first line of managed code.

They are,

• System Domain
• Shared Domain
• Default Domain

System Domain

The System domain(Singleton) is responsible for creating and initializing the shared and default domain in the worker process.It loads mscorlib.dll into shared domain and keeps in thrack of all the domains in the process.System domain implements the functionality of loading and unloading the AppDomains.Because it is singleton only one instance of the AppDomain will be running.

Shared Domain

The Shared domain(Singleton) host the domain neutral assemblies ie assemblies used by all Domains which is the core system library(mscorlib.dll).One of the advantage of hosting domain neutral assembly in shared domain is to reuse the jitted code accross the process that host the application domains which increases the speed of the application.Because it is singleton only one instance of the AppDomain will be running.

Default Domain

Default Domain is the instance of AppDomain where the application code is executed.Some applications that require additional AppDomains creates it at runtime.

Regards,

Satheesh