1 / 56

Microsoft's .NET Implementation

Microsoft's .NET Implementation. Matthew Conover April 2002. What is .NET?. .NET = dumb name .NET != web services .NET is a framework .NET is platform independent .NET is language insensitive .NET specs are publicly available. Topics of Discussion. Introduction to .NET Assemblies

Mia_John
Download Presentation

Microsoft's .NET Implementation

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Microsoft's .NET Implementation Matthew Conover April 2002

  2. What is .NET? • .NET = dumb name • .NET != web services • .NET is a framework • .NET is platform independent • .NET is language insensitive • .NET specs are publicly available

  3. Topics of Discussion • Introduction to .NET • Assemblies • Microsoft’s implementation of .NET • .NET Hook (dotNetHook) tool

  4. Introduction to .NET • .NET CLI specifications (ECMA) • Partition I – Architecture • Partition II – Metadata • Partition III – CIL • Partition IV – Library • Partition V – Annexes • Class Library (XML specification)

  5. Introduction to .NET • Base Class Library (BCL) • Shared among all languages • Common Language Runtime (CLR) • Common Type System (CTS) • Common Language Specification (CLS) • Execution Engine

  6. Base Class Library • Similar to Java’s System namespace. • Has classes for IO, threading, database, text, graphics, console, sockets/web/mail, security, cryptography, COM, run-time type discovery/invocation, assembly generation

  7. Common Language Runtime • Common Type Specification • Specifies certain types required to be hosted by CLR • Specifies rules for class, structure, enumeration, interfaces, delegates, etc. • Everything is actually an object

  8. Common Language Runtime • Execution Engine • Handles object layout/references • Handles garbage collection • Managed heap • Enforces code access security • Handles verification • Safe methods can only do safe things • Compiles MSIL (bytecode) into native code

  9. Common Language Runtime Assembly BCL Class Loader External Assembly JIT Execution Engine Machine Code

  10. Assemblies • Single-file or multi-file assemblies • Components: • Manifest • Metadata • MSIL (or native) code • Resources

  11. Manifest • Defines assembly • Strong name • Files in the assembly • Type references • Referenced assemblies

  12. Metadata • Contains all .NET data • Streams • #Strings • #Blob • #GUID • #US • #- or #~ • Tables (stored in #- or #~) • In a predefined order • I.e., MethodDef, AssemblyRef, Constant

  13. Metadata Signature, Version, Flags Stream count Metadata Header Data offset Stream size Name Stream Header 1 … Stream Header 2 … Stream bodies

  14. #~ and #- Stream Version Heap sizes Valid tables Sorted tables Tables Header Table row count Valid Table 1 … Valid Table 2 … Table bodies

  15. MethodDef Table (0x06) RVA Offset to method Implementation flags Method flags Method name Offset into #Strings Signature Offset into #Blob Parameters Index into Param table (0x08)

  16. MethodDef Table (0x06) Param Table (0x08) Flags Sequence number Parameter name Offset into #Strings Signature Blob Flags Parameter count Return type Parameter types

  17. MSIL • Pseudo-assembly • nop, break, ret, call, callvirt, newobj, newarr, add, mul, xor, arglist, sizeof, throw, catch, dup • 0xFE = first byte of two byte opcodes • Uses “tokens” instead of offsets/pointers • All calls are stack based • “this” pointer passed as first argument • Arguments passed left-to-right by default • varargs passes an extra signature

  18. MSIL IL Assembler 0x1f 0x09 0x28 0x06000006 ldc.i4.s 9 call Print(Int32) Method token Token Table Number Row Index Upper 8 bits Lower 24 bits

  19. Call Stack ldc.i4.1 ldc.i4.2 call ClassType::func(Int32, Int32) ClassType a; a.func(1, 2) 1 2 this pointer Stack top Left-to-right ordering

  20. MSIL Samples • Ldloc • Puts value on stack from a local variable • Ldarg • Puts an argument on the stack • Ldlen • Puts the length of an array on the stack • Ldelem • Puts the value of an element on the stack • Ld*a • Puts the address of something on the stack

  21. MSIL Samples (cont.) • Brtrue <target> • Branch to target if value on stack is true • Dup • Duplicate a value on the stack • Ldnull • Puts a null value on the stack

  22. Microsoft’s .NET Implementation • %SystemRoot%\Microsoft.NET • %SystemRoot%\Assembly + • \GAC • \NativeImages*

  23. System Libraries • mscoree.dll (execution engine) • mscorjit.dll (contains JIT) • mscorsn.dll (strong name) • mscorlib.dll (BCL) • fushion.dll (assembly binding)

  24. .NET Application • Jumps to _CorExeMain (mscoree) • Calls _CorExeMain in mscorwks.dll • _CorExeMain calls CoInitializeEE • CoInitializeEE calls: • EEStartup • ExecuteEXE

  25. EEStartup • GCHeap.Initialize • Managed heap = Doug Lea’s malloc? • ECall.Init • SetupGenericPInvokeCalliStub • PInvokeCalliWorker • NDirect.Init • UMThunkInit.UMThunkInit • COMDelegate.Init • ExecutionManger.Init • COMNlsInfo.InitializeNLS

  26. EEStartup (cont.) • Security::Start • SystemDomain.Init • Loads BCL • SystemDomain.NotifyProfilerStartup • SystemDomain.NotifyNewDomainLoads • SystemDomain.PublishAppDomainAndInformDebugger (ICorPublish/ICorDebug)

  27. SystemDomain.Init • LoadBaseSystemClasses • SystemDomain.CreatePreallocatedExceptions

  28. LoadBaseSystemClasses • SystemDomain.LoadSystemAssembly • Loads mscorlib.dll • Binder::StartupMscorlib • Binder::FetchClass(OBJECT) • MethodTable::InitForFinalization • InitJITHelpers2 • Binder::FetchClass(VALUE) • Binder::FetchClass(ARRAY)

  29. LoadBaseSystemClasses • Binder.FetchType(OBJECT_ARRAY) • Binder.FetchClass(STRING) • Binder.FetchClass(ENUM) • Binder.FetchClass(ExceptionClass) • Binder.FetchClass(OutOfMemoryExceptionClass) • Binder.FetchClass(StackOverflowExceptionClass)

  30. LoadBaseSystemClasses • Binder.FetchClass(ExecutionEngineExceptionClass) • Binder.FetchClass(DelegateClass) • Binder.FetchClass(MultiDelegateClass)

  31. .NET Application (review) • Jumps to _CorExeMain (mscoree) • Calls _CorExeMain in mscorwks.dll • _CorExeMain calls CoInitializeEE • CoInitializeEE calls: • EEStartup • ExecuteEXE

  32. ExecuteEXE • StrongNamesignatureVerification • In mscorsn.dll • PEFile::Create • Loads executable • ExecuteMainMethod • FushionBind.CreateFushionName • Assembly.ExecuteMainMethod

  33. ExecuteMainMethod • Thread.EnterRestrictiedContext • PEFile::GetMDImport • SystemDomain.SetDefaultDomainAttributes • Sets entry point • SystemDomain.InitializeDefaultDomain • BaseDomain.LoadAssembly

  34. BaseDomain.LoadAssembly • BaseDomain.ApplySharePolicy • AssemblySecurityDescriptor.Init • Module.Create • BaseDomain.SetAssemblyManifestModule • AssemblySecurityDescriptor.AddDescriptorToDomainList

  35. ExecuteEXE (review) • StrongNamesignatureVerification • In mscorsn.dll • PEFile::Create • Loads executable • ExecuteMainMethod • FushionBind.CreateFushionName • Assembly.ExecuteMainMethod

  36. Assembly.ExecuteMainMethod • Assembly::GetEntryPoint • ClassLoader::ExecuteMainMethod • EEClass:FindMethod(entry point token)

  37. EEClass.FindMethod • ValidateMainMethod • CorCommandLine.GetArgvW • MethodDesc.Call • MethodDesc.IsRemotingIntercepted • MethodDesc.CallDescr calls MethodDesc.CallDescrWorker • CallDescrWorker calls Main()

  38. .NET Application • Main() needs to be compiled • Main() calls PreStubWorker (mscorwks) • PreStubWorker • Compiles all IL methods • Calls MethodDesc.DoPrestub

  39. MethodDesc.DoPrestub • MethodDesc.GetSecurityFlags • MethodDesc.GetUnsafeAddrofCode • MethodDesc.GetILHeader • MethodDesc.GetRVA • COR_DECODE_METHOD • Decode tiny/fat format • Security._CanSkipVerification

  40. MethodDesc.DoPrestub • EEConfig.ShouldJitMethod • MakeJitWorker • JITFunction • GetPrejittedCode

  41. JITFunction • ExecutionManager::GetJitForType • EEJitManager::LoadJIT • Loads mscorjit.dll (in LoadJIT) • Calls getJit in mscorjit (in LoadJIT) • CallCompileMethodWithSEHWrapper • Debugger.JitBeginning • CILJit.compileMethod • Debugger.JitComplete

  42. CILJit.compileMethod • Calls jitNativeCode • jitNativeCode • Compiler.compInit • Compiler.compCompile

  43. Compiler.compCompile • Compiler.eeGetMethodClass • Compiler.eeGetClassAttribs • emitter.emitBegCG • Compiler.eeGetMethodAttribs • Compiler.comptInitDebuggingInfo • Compiler.genGenerateCode • emitter.emitEndCG

  44. Compiler.genGenerateCode • emitter.emitBegFN • Compiler.genCodeForBBlist • Compiler.genFnProlog • Compiler.genFnEpilog • emitter.emitEndCodeGen • Compiler.gcInfoBlocKHdrSave • emitter.emitEndFN

  45. .NET Application • Show flowchart

  46. .NET Hook • Reads through method table • Reads method • Parses header, code, EH data • Hooks interest functions • Inserts hooked code at front of method • Stored at the end of the .text section • Updates PE and section headers • Changes function RVAs in Metadata

  47. Method Definition (review) RVA Offset to method Implementation flags Method flags Method name Offset into #Strings Signature Offset into #Blob Parameters Index into Param table (0x08)

  48. Tiny Method Body • Header size = 1 byte • Used when: • Maximum stack size is less than 8 • The method has no local variables • No extra data section • No exceptions

  49. Tiny Method Header (flags and code size) Method body (IL)

  50. Fat Method • Header size = 12 bytes Flags Header size Max. stack size Code size Local var. signature Describes local variables Method body (IL) Extra data sections Currently only used for exceptions

More Related