SOS Extension Commands

SOS Extension Commands

There are many WinDbg debugger extensions. Among them SOS extension is pretty popular and useful for .NET debugging. The SOS debugger extension (SOS.dll) helps you debug .NET managed application in the WinDbg by providing information about the internal Common Language Runtime (CLR) environment. All debugger extension commands start with bang(!). The following table shows frequently used SOS extension commands.

Command Description Example
!clrstack Display a stack trace of managed code only !clrstack -a
!comstate List the COM apartment model for each thread and a Context pointer if available !comstate
!dumpdomain List AppDomain(s) and its assemblies. !dumpdomain
!dumpassembly Display assembly information !dumpassembly 02fe1bd8
!dumpmodule Displays information about a module at the specified address !dumpmodule /d 03224014
!dumpclass Display information about the EEClass structure associated with a type !dumpclass 60be6004
!dumpobj Display information about an object at the specified address !dumpobj /d 04a0226c
!dumpvc Display information about the fields of a value class at the specified address !dumpvc 61061a90 004ff2c4
!dumparray Display elements of an array object. !dumparray 1da226ec
!dumpmt Display information about a method table at the specified address. The -md option displays a list of all methods defined with the object. !dumpmt -md 02c74dc0
!dumpmd Display information about a MethodDesc structure at the specified address !dumpmd 60b474e0
!bpmd Create a breakpoint at the specified method in the specified module !bpmd Mydll.dll MyNS.Calc..ctor
!dumpheap Display the managed heap information and statistics about heap objects. !dumpheap -stat (display statistical type summary only)
!dumpil Display the MSIL that is associated with a method !dumpil 60b474e0
!dumpstack Display stack trace !dumpstack
!dumpstackobjects (!dso) Display all managed objects found within the bounds of the current stack !dso
!eeheap Display information about process memory consumed by internal CLR data structures !eeheap
!eestack Display stack traces for all threads !eestack
!eeversion Display the CLR version !eeversion
!finalizequeue Display all objects registered for finalization !finalizequeue
!gchandles Display statistics about GC handles !gchandles
!gchandleleaks Check any leak for GC handles !gchandleleaks
!gcroot Display information about references (or roots) to an object !gcroot 0459226c
!gcwhere Display the location and size in the GC heap for an object !gcwhere 0459226c
!help (!sos.help) Display help !help gcwhere (help about gcwhere)
!heapstat Display the generation sizes and free spaces for each heap !heapstat
!ip2md Get the method name for jitted code address !ip2md 028204fe
!name2ee Display the MethodTable and EEClass structure for the specified type or method in the specified module !name2ee DbgTest.exe DbgTest.Calc
!objsize Display the size of the specified object !objsize 0459226c
!printexception Display formatted output of any object derived from the Exception class !pe 04592260
!procinfo Display environment variables for the process, CPU and memory statistics !procinfo
!savemodule Writes an image, which is loaded in memory at the specified address, to the specified file !savemodule 001d4014 c:\temp\test.exe
!stoponexception Stop the debugger when the specified exception is thrown !soe -create System.IndexOutOfRangeException 1
!syncblk Display SyncBlock structure(s) !syncblk
!threadpool Display managed thread pool information !threadpool
!threads Display all managed threads in the process !threads
!u Display an annotated disassembly of a managed method. Specify either by a MethodDesc structure pointer for the method or by a code address within the method body. !u 03244e24
!verifyheap Check the GC heap corruption !verifyheap
!vmstat Display summary view of the virtual address space !vmstat
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