1. .NET and .NET Core
2. .NET Runtimes
Pan Wuming
2017

2. Copyright © 2012 by Jeffrey Richter

4. .NET runtimes Common Language Runtime (CLR) for the .NET Framework
Core Common Language Runtime (CoreCLR) for .NET Core
.NET Native for Universal Windows Platform
The Mono runtime for Xamarin.iOS, Xamarin.Android, Xamarin.Mac, and the Mono desktop framework

5. Topics .NET Application Common Language Runtime (CLR)
Assembly: Application Unit
Metadata
Runtime host
Application domains

6. IL: intermediate language
.NET Application
A .NET Application contains one or more Assemblies
An assembly contains Metadata and IL Code, and resources, within one or many files
A .NET Application must run in a host environment
The execution of a .NET Application is Managed by CLR
IL: intermediate language
Self-Host?

7. Managed execution process
Choosing a compiler.
Compiling your code to MSIL.
Compiling MSIL to native code.
Running code.
Managed By CLR
Create Assembly

8. Common Language Runtime (CLR)

9. CLR Services Class Layout Security JIT Compiler Other Runtime Services
Type Awareness
Exception
Integration
JIT Compiler
Other Runtime Services
Class Layout
Memory
& GC
Security

10. The Roles of CLR Compiler Assembly Development Source code C# VB F# …
public static void Main(String[] args )
usr=Environment.GetEnvironmentVariable("USERNAME");
try {
{ String usr; FileStream f; StreamWriter w;
w.WriteLine(usr);
w=new StreamWriter(f);
f=new FileStream(“C:\\test.txt",FileMode.Create);
Console.WriteLine("Exception:"+e.ToString());
} catch (Exception e){
w.Close(); }
Compiler
public static void Main(String[] args )
usr=Environment.GetEnvironmentVariable("USERNAME");
try {
{ String usr; FileStream f; StreamWriter w;
w.WriteLine(usr);
w=new StreamWriter(f);
f=new FileStream(“C:\\test.txt",FileMode.Create);
Console.WriteLine("Exception:"+e.ToString());
} catch (Exception e){
w.Close(); }
Source code C# VB F# …
MSIL
Metadata
Resources

11. Global Assembly Cache (GAC) Application Directory
The Roles of CLR
Assembly
Development
Compiler
Assembly
Development C# VB F# …
MSIL
Metadata
Resources
public static void Main(String[] args )
usr=Environment.GetEnvironmentVariable("USERNAME");
try {
{ String usr; FileStream f; StreamWriter w;
w.WriteLine(usr);
w=new StreamWriter(f);
f=new FileStream(“C:\\test.txt",FileMode.Create);
Console.WriteLine("Exception:"+e.ToString());
} catch (Exception e){
w.Close(); }
Source code
Global Assembly Cache (GAC)
Install
Setup
Copy
Browser
Application Directory
Download Cache

12. The Roles of CLR Assembly on Target Machine
Development
Application Directory
Setup
Copy
Browser
Download Cache
Deployment
Assembly on Target Machine
Global Assembly Cache (GAC)
Install
Policy
<security>
<mscorlib>
<configuration>
<?xml version="1.0" encoding="utf-8" ?>
<policy>
version="1"
<CodeGroup class="UnionCodeGroup"
<PolicyLevel version="1">
PermissionSetName="Nothing"
Description="Code group grants no permissio ns and forms the root of the code group tree.">
Name="All_Code"
<IMembershipCondition clas s="AllMembershipCondition"
version="1"/>
PermissionSetName="FullTrust"
Execution
IL to Native Compiler
Class Loader
Security
Assembly
Loader
Garbage Collection
Native code + GC table
Code Manager
Exception Manager
Thread Support
COM Interop
Debug Engine

13. Benefits of Presence of the CLR
Performance improvements
Cross-language integration
Cross-language exception handling
Enhanced security
Versioning and deployment support
A simplified model for component interaction
Debugging and profiling services.

14. Assembly: Application Unit
Contains Code
Security boundary.
Type boundary
Reference scope boundary
Version boundary
Deployment unit
To support Side-by-side execution

16. Manifest Enumerates the files that make up the assembly.
Governs how references to the assembly's types and resources map to the files that contain their declarations and implementations.
Enumerates other assemblies on which the assembly depends.
Provides a level of indirection between consumers of the assembly and the assembly's implementation details.
Renders the assembly self-describing.

17. GAC and Strong-Named Assembly
Global Assembly Cache: Machine-wide Code Cache
Strongly Named Assemblies Are Tamper-Resistant
Strong-Named
the simple text name
the version number
optional culture information
a digital signature, and the token of the public key that corresponds to the private key used for signing.
Delay Signing or Partial Signing an Assembly
Assemblies deployed in the GAC must have a strong name

18. Signing an assembly

19. The AssemblyRef metadata information

20. Metadata within a PE File
PE section
Contents of PE section
PE header
The index of the PE file's main sections
the address of the entry point.
MSIL instructions
The Microsoft intermediate language instructions (MSIL)
Accompanied by metadata tokens.
Metadata
Metadata tables and heaps
Every type and member
Custom attributes
Security information.
Win32 Portable Executable File Format

21. Metadata Tables and Heaps
Each metadata table holds information about a certain type of elements of your program
Method, type, and so on
Metadata also stores information in four heap structures
String
Blob: binary objects of arbitrary size
user string
GUID: 16-byte binary objects
Metadata tokens are used in MSIL to reference a row of a particular metadata table.

22. Application Domains
Application domains are typically created by runtime hosts
To provide isolation between assemblies
Objects that pass between domains are either copied or accessed by proxy

23. Runtime Hosts
Shell executables IE
ASP.NET
Before any managed code can be executed, the host must load and initialize the CLR.
Loads the runtime into a process
Creates the application domains within the process
Loads user code into the application domains
The hosting APIs
All hosts start with an unmanaged stub because the runtime is not yet running in the process.
C++!
#include <metahost.h>
#pragma comment(lib, "mscoree.lib") …
hr = CLRCreateInstance(CLSID_CLRMetaHost,
IID_ICLRMetaHost, (LPVOID*)&pMetaHost);

24. Finally, These are the key words:
Common Language Runtime (CLR)
Assembly
Metadata
Manifest
Global Assembly Cache(GAC)
Strong Named Assembly
Intermediate language (IL)
Delay Sign
JIT Complier
Garbage collection (GC)