.NET debugger extensions

The .NET debugger extensions let you view information about code that's running inside the .NET runtime, both on live processes and dumps. The extensions are preinstalled with Windbg, and can be downloaded for use with LLDB. You can use the .NET debugger extensions to:

  • Collect information about the managed heap.
  • Look for heap corruptions.
  • Display internal data types used by the runtime.
  • View information about all managed code running inside the runtime.

The .NET debugger extensions include commands from the existing dotnet-sos tool as well as new commands. A limited set of commands are also now supported for the Native AOT runtime.

Syntax

Under windbg: ![command] [options]

Under LLDB: sos [command] [options]

Many of the commands have aliases or shortcuts under LLDB: clrstack [options]

Commands

The following table of commands is also available under Help or soshelp. Individual command help is available using soshelp <command>.

Command Description
bpmd [-nofuturemodule] [<module name> <method name>] [-md <MethodDesc>] -list -clear <pending breakpoint number> -clearall Creates a breakpoint at the specified method in the specified module.

If the specified module and method has not been loaded, this command waits for a notification that the module was loaded and just-in-time (JIT) compiled before creating a breakpoint.

You can manage the list of pending breakpoints by using the -list, -clear, and -clearall options:

The -list option generates a list of all the pending breakpoints. If a pending breakpoint has a nonzero module ID, that breakpoint is specific to a function in that particular loaded module. If the pending breakpoint has a zero module ID, that breakpoint applies to modules that has not yet been loaded.

Use the -clear or -clearall option to remove pending breakpoints from the list.
CLRStack [-a] [-l] [-p] [-n] [-f] [-r] [-all] Provides a stack trace of managed code only.

The -p option shows arguments to the managed function.

The -l option shows information on local variables in a frame. The .NET debugger extensions cannot retrieve local names, so the output for local names is in the format <local address> = <value>.

The -a option is a shortcut for -l and -p combined.

The -n option disables the display of source file names and line numbers. If the debugger has the option SYMOPT_LOAD_LINES specified, SOS looks up the symbols for every managed frame and if successful, displays the corresponding source file name and line number. The -n (No line numbers) parameter can be specified to disable this behavior.

The -f option (full mode) displays the native frames intermixing them with the managed frames and the assembly name and function offset for the managed frames. This option does not display native frames when used with dotnet-dump.

The -r option dumps the registers for each stack frame.

The -all option dumps the stacks of all the managed threads.
COMState Lists the COM apartment model for each thread and a Context pointer, if available. This command is only supported on Windows.
DumpArray [-start <startIndex>] [-length <length>] [-details] [-nofields] <array object address>

-or-

DA [-start <startIndex>] [-length <length>] [-details] [-nofields] array object address>
Examines elements of an array object.

The -start option specifies the starting index at which to display elements.

The -length option specifies how many elements to show.

The -details option displays details of the element using the DumpObj and DumpVC formats.

The -nofields option prevents arrays from displaying. This option is available only when the -details option is specified.
DumpAsync (dumpasync) [-mt <MethodTable address>] [-type <partial type name>] [-waiting] [-roots] DumpAsync traverses the garbage-collected heap and looks for objects representing async state machines as created when an async method's state is transferred to the heap. This command recognizes async state machines defined as async void, async Task, async Task<T>, async ValueTask, and async ValueTask<T>.

The output includes a block of details for each async state machine object found. These details include:
- A line for the type of the async state machine object, including its MethodTable address, its object address, its size, and its type name.
- A line for the state machine type name as contained in the object.
- A listing of each field on the state machine.
- A line for a continuation from this state machine object, if one or more has been registered.
- Discovered GC roots for this async state machine object.

Supported for Native AOT applications.
DumpAssembly <assembly address> Displays information about an assembly.

The DumpAssembly command lists multiple modules, if they exist.

You can get an assembly address by using the DumpDomain command.
DumpClass <EEClass address> Displays information about the EEClass structure associated with a type.

The DumpClass command displays static field values but does not display nonstatic field values.

Use the DumpMT, DumpObj, Name2EE, or Token2EE command to get an EEClass structure address.
DumpDomain [<domain address>] Enumerates each Assembly object that's loaded within the specified AppDomain object address. When called with no parameters, the DumpDomain command lists all AppDomain objects in a process. Since .NET (Core) only has one AppDomain, DumpDomain only returns one object.
DumpHeap [-stat] [-strings] [-short] [-min <size>] [-max <size>] [-thinlock] [-startAtLowerBound] [-mt <MethodTable address>] [-type <partial type name>] [start [end]] Displays information about the garbage-collected heap and collection statistics about objects.

The DumpHeap command displays a warning if it detects excessive fragmentation in the garbage collector heap.

The -stat option restricts the output to the statistical type summary.

The -strings option restricts the output to a statistical string value summary.

The -short option limits output to just the address of each object. This command lets you easily pipe output from the command to another debugger command for automation.

The -min option ignores objects that are less than the size parameter, specified in bytes.

The -max option ignores objects that are larger than the size parameter, specified in bytes.

The -thinlock option reports ThinLocks. For more information, see the SyncBlk command.

The -startAtLowerBound option forces the heap walk to begin at the lower bound of a supplied address range. During the planning phase, the heap is often not walkable because objects are being moved. This option forces DumpHeap to begin its walk at the specified lower bound. You must supply the address of a valid object as the lower bound for this option to work. You can display memory at the address of a bad object to manually find the next method table. If the garbage collection is currently in a call to memcopy, you may also be able to find the address of the next object by adding the size to the start address, which is supplied as a parameter.

The -mt option lists only those objects that correspond to the specified MethodTable structure.

The -type option lists only those objects whose type name is a substring match of the specified string.

The start parameter begins listing from the specified address.

The end parameter stops listing at the specified address.

Supported for Native AOT applications.
DumpIL <Managed DynamicMethod object> | <DynamicMethodDesc pointer> | <MethodDesc pointer> Displays the common intermediate language (CIL) that's associated with a managed method.

Dynamic CIL is emitted differently than CIL that's loaded from an assembly. Dynamic CIL refers to objects in a managed object array rather than to metadata tokens.
DumpLock [--allthreads] [--waits] Displays information about System.Threading.Lock objects, such as those being held by threads (default), or those being waited upon by threads.
DumpLog [-addr <addressOfStressLog>] [<Filename>] Writes the contents of an in-memory stress log to the specified file. If you do not specify a name, this command creates a file called StressLog.txt in the current directory.

The in-memory stress log helps you diagnose stress failures without using locks or I/O. To enable the stress log, set the following registry keys under HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\.NETFramework:

(DWORD) StressLog = 1

(DWORD) LogFacility = 0xffffffff

(DWORD) StressLogSize = 65536

The optional -addr option lets you specify a stress log other than the default log.

Supported for Native AOT applications.
DumpMD <MethodDesc address> Displays information about a MethodDesc structure at the specified address.

You can use the IP2MD command to get the MethodDesc structure address from a managed function.
DumpMT [-MD] <MethodTable address> Displays information about a method table at the specified address. Specifying the -MD option displays a list of all methods defined with the object.

Each managed object contains a method table pointer.
DumpModule [-mt] <Module address> Displays information about a module at the specified address. The -mt option displays the types defined in a module and the types referenced by the module

You can use the DumpDomain or DumpAssembly command to retrieve a module's address.
DumpObj [-nofields] <object address>

-or-

DO <object address>
Displays information about an object at the specified address. The DumpObj command displays the fields, the EEClass structure information, the method table, and the size of the object.

You can use the DumpStackObjects command to retrieve an object's address.

You can run the DumpObj command on fields of type CLASS because they are also objects.

The -nofields option prevents fields of the object being displayed, it is useful for objects like String.
DumpRuntimeTypes Displays the runtime type objects in the garbage collector heap and lists their associated type names and method tables.
DumpStack [-EE] [-n] [top stack [bottom stack]] Displays a stack trace.

The -EE option causes the DumpStack command to display only managed functions. Use the top and bottom parameters to limit the stack frames displayed on x86 platforms.

The -n option disables the display of source file names and line numbers. If the debugger has the option SYMOPT_LOAD_LINES specified, SOS will look up the symbols for every managed frame and if successful displays the corresponding source file name and line number. The -n (No line numbers) parameter can be specified to disable this behavior.
DumpSig <sigaddr> <moduleaddr> Displays information about a Sig structure at the specified address.
DumpSigElem <sigaddr> <moduleaddr> Displays a single element of a signature object. In most cases, you should use DumpSig to look at individual signature objects. However, if a signature has been corrupted in some way, you can use DumpSigElem to read the valid portions of it.
DumpStackObjects [-verify] [top stack [bottom stack]]

-or-

DSO [-verify] [top stack [bottom stack]]
Displays all managed objects found within the bounds of the current stack.

The -verify option validates each nonstatic CLASS field of an object field.

Use the DumpStackObject command with stack tracing commands such as K (windbg) or bt (lldb) along with the clrstack command to determine the values of local variables and parameters.
DumpVC <MethodTable address> <Address> Displays information about the fields of a value class at the specified address.

The MethodTable parameter allows the DumpVC command to correctly interpret fields. Value classes do not have a method table as their first field.
EEHeap [-gc] [-loader] Displays information about process memory consumed by internal runtime data structures.

The -gc and -loader options limit the output of this command to garbage collector or loader data structures.

The information for the garbage collector lists the ranges of each segment in the managed heap. If the pointer falls within a segment range given by -gc, the pointer is an object pointer.
EEStack [-short] [-EE] Runs the DumpStack command on all threads in the process.

The -EE option is passed directly to the DumpStack command. The -short parameter limits the output to the following kinds of threads:

Threads that have taken a lock.

Threads that have been stalled in order to allow a garbage collection.

Threads that are currently in managed code.
EHInfo [<MethodDesc address>] [<Code address>] Displays the exception handling blocks in a specified method. This command displays the code addresses and offsets for the clause block (the try block) and the handler block (the catch block).
FAQ Displays frequently asked questions. Not supported in dotnet-dump.
FinalizeQueue [-detail] | [-allReady] [-short] Displays all objects registered for finalization.

The -detail option displays extra information about any SyncBlocks that need to be cleaned up, and any RuntimeCallableWrappers (RCWs) that await cleanup. Both of these data structures are cached and cleaned up by the finalizer thread when it runs.

The -allReady option displays all objects that are ready for finalization, regardless of whether they are already marked by the garbage collection as such, or will be marked by the next garbage collection. The objects that are in the "ready for finalization" list are finalizable objects that are no longer rooted. This option can be expensive, because it verifies whether all the objects in the finalizable queues are still rooted.

The -short option limits the output to the address of each object. If it is used in with -allReady, it enumerates all objects that have a finalizer that are no longer rooted. If it is used independently, it lists all objects in the finalizable and "ready for finalization" queues.
FindAppDomain <Object address> Determines the application domain of an object at the specified address.
FindRoots -gen <N> | -gen any |<object address> Causes the debugger to break in the debuggee on the next collection of the specified generation. The effect is reset as soon as the break occurs. To break on the next collection, you have to reissue the command. The <object address> form of this command is used after the break caused by the -gen or -gen any has occurred. At that time, the debuggee is in the right state for FindRoots to identify roots for objects from the current condemned generations. Only supported on Windows.
GCHandles [-perdomain] Displays statistics about garbage collector handles in the process.

The -perdomain option arranges the statistics by application domain.

Use the GCHandles command to find memory leaks caused by garbage collector handle leaks. For example, a memory leak occurs when code retains a large array because a strong garbage collector handle still points to it, and the handle is discarded without freeing it.

Only supported on Windows.
GCHandleLeaks Searches memory for any references to strong and pinned garbage collector handles in the process and displays the results. If a handle is found, the GCHandleLeaks command displays the address of the reference. If a handle is not found in memory, this command displays a notification. Only supported on Windows.
GCInfo <MethodDesc address><Code address> Displays data that indicates when registers or stack locations contain managed objects. If a garbage collection occurs, the collector must know the locations of references to objects so it can update them with new object pointer values.
GCRoot [-nostacks] [-all] <Object address> Displays information about references (or roots) to an object at the specified address.

The GCRoot command examines the entire managed heap and the handle table for handles within other objects and handles on the stack. Each stack is then searched for pointers to objects, and the finalizer queue is also searched.

This command does not determine whether a stack root is valid or is discarded. Use the clrstack and U commands to disassemble the frame that the local or argument value belongs to in order to determine if the stack root is still in use.

The -nostacks option restricts the search to garbage collector handles and reachable objects.

The -all option forces all roots to be displayed instead of just the unique roots.
GCWhere <object address> Displays the location and size in the garbage collection heap of the argument passed in. When the argument lies in the managed heap but is not a valid object address, the size is displayed as 0 (zero).
Help (soshelp) [<command>] [faq] Displays all available commands when no parameter is specified, or displays detailed help information about the specified command.

The faq parameter displays answers to frequently asked questions.
HeapStat [-inclUnrooted | -iu] Displays the generation sizes for each heap and the total free space in each generation on each heap. If the -inclUnrooted option is specified, the report includes information about the managed objects from the garbage collection heap that is no longer rooted. Only supported on Windows.
HistClear Releases any resources used by the family of Hist commands.

Generally, you do not have to explicitly call HistClear, because each HistInit cleans up the previous resources.
HistInit Initializes the SOS structures from the stress log saved in the debuggee.
HistObj <obj_address> Examines all stress log relocation records and displays the chain of garbage collection relocations that may have led to the address passed in as an argument.
HistObjFind <obj_address> Displays all the log entries that reference an object at the specified address.
HistRoot <root> Displays information related to both promotions and relocations of the specified root.

The root value can be used to track the movement of an object through the garbage collections.
IP2MD (ip2md) <Code address> Displays the MethodDesc structure at the specified address in code that has been JIT-compiled.
ListNearObj (lno) <obj_address> Displays the objects preceding and following the specified address. The command looks for the address in the garbage collection heap that looks like a valid beginning of a managed object (based on a valid method table) and the object following the argument address. Only supported on Windows.
MinidumpMode [0] [1] Prevents running unsafe commands when using a minidump.

Pass 0 to disable this feature or 1 to enable this feature. By default, the MinidumpMode value is set to 0.

Minidumps created with the .dump /m command or .dump command have limited CLR-specific data and allow you to run only a subset of SOS commands correctly. Some commands may fail with unexpected errors because required areas of memory are not mapped or are only partially mapped. This option protects you from running unsafe commands against minidumps.

Only supported with Windbg.
Name2EE (name2ee) <module name> <type or method name>

-or-

Name2EE <module name>!<type or method name>
Displays the MethodTable structure and EEClass structure for the specified type or method in the specified module.

The specified module must be loaded in the process.

To get the proper type name, browse the module by using the Ildasm.exe (IL Disassembler). You can also pass * as the module name parameter to search all loaded managed modules. The module name parameter can also be the debugger's name for a module, such as mscorlib or image00400000.

This command supports the Windows debugger syntax of <module>!<type>. The type must be fully qualified.
ObjSize [<Object address>] | [-aggregate] [-stat] Displays the size of the specified object. If you do not specify any parameters, the ObjSize command displays the size of all objects found on managed threads, displays all garbage collector handles in the process, and totals the size of any objects pointed to by those handles. The ObjSize command includes the size of all child objects in addition to the parent.

The -aggregate option can be used in with the -stat argument to get a detailed view of the types that are still rooted. By using !dumpheap -stat and !objsize -aggregate -stat, you can determine which objects are no longer rooted and diagnose various memory issues.

Only supported on Windows.
PrintException [-nested] [-lines] [<Exception object address>]

-or-

PE [-nested] [<Exception object address>]
Displays and formats fields of any object derived from the Exception class at the specified address. If you do not specify an address, the PrintException command displays the last exception thrown on the current thread.

The -nested option displays details about nested exception objects.

The -lines option displays source information, if available.

You can use this command to format and view the _stackTrace field, which is a binary array.
ProcInfo [-env] [-time] [-mem] Displays environment variables for the process, kernel CPU time, and memory usage statistics. Only supported with Windbg.
RCWCleanupList <RCWCleanupList address> Displays the list of runtime callable wrappers at the specified address that are awaiting cleanup. Only supported with Windbg.
SaveModule <Base address> <Filename> Writes an image, which is loaded in memory at the specified address, to the specified file. Only supported with Windbg.
SetHostRuntime [<runtime-directory>] This command sets the path to the .NET runtime to use to host the managed code that runs as part of SOS in the debugger (LLDB). The runtime needs to be at least version 2.1.0 or greater. If there are spaces in directory, it needs to be single-quoted (').

Normally, SOS attempts to find an installed .NET runtime to run its managed code automatically but this command is available if it fails. The default is to use the same runtime (libcoreclr) being debugged. Use this command if the default runtime being debugged isn't working enough to run the SOS code or if the version is less than 2.1.0.

If you received the following error message when running a SOS command, use this command to set the path to 2.1.0 or greater .NET runtime.

(lldb) clrstack
Error: Fail to initialize CoreCLR 80004005 ClrStack failed

(lldb) sethostruntime /usr/share/dotnet/shared/Microsoft.NETCore.App/2.1.6

You can use the "dotnet --info" in a command shell to find the path of an installed .NET runtime.
SetSymbolServer [-ms] [-disable] [-log] [-loadsymbols] [-cache <cache-path>] [-directory <search-directory>] [-sympath <windows-symbol-path>] [<symbol-server-URL>] Enables the symbol server downloading support.

The -ms option enables downloading from the public Microsoft symbol server.

The -disable option turns on the symbol download support.

The -cache <cache-path> option specifies a symbol cache directory. The default is $HOME/.dotnet/symbolcache if not specified.

The -directory option adds a path to search for symbols. Can be more than one.

The -sympath option adds server, cache, and directory paths in the Windows symbol path format.

The -log option enables symbol download logging.

The -loadsymbols option attempts to download the native .NET symbols for the runtime. Supported on lldb and dotnet-dump.
SOSFlush Flushes an internal SOS cache.
SOSStatus [-reset] Displays internal SOS status or reset the internal cached state.
StopOnException [-derived] [-create | -create2] <Exception> <Pseudo-register number> Causes the debugger to stop when the specified exception is thrown, but to continue running when other exceptions are thrown.

The -derived option catches the specified exception and every exception that derives from the specified exception.

Only supported with Windbg.
SyncBlk [-all | <syncblk number>] Displays the specified SyncBlock structure or all SyncBlock structures. If you do not pass any arguments, the SyncBlk command displays the SyncBlock structure corresponding to objects that are owned by a thread.

A SyncBlock structure is a container for extra information that does not need to be created for every object. It can hold COM interop data, hash codes, and locking information for thread-safe operations.
ThreadPool Displays information about the managed thread pool, including the number of work requests in the queue, the number of completion port threads, and the number of timers.
Threads (clrthreads) [-live] [-special] Displays all managed threads in the process.

The Threads command displays the debugger shorthand ID, the CLR thread ID, and the operating system thread ID. Additionally, the Threads command displays a Domain column that indicates the application domain in which a thread is executing, an APT column that displays the COM apartment mode, and an Exception column that displays the last exception thrown in the thread.

The -live option displays threads associated with a live thread.

The -special option displays all special threads created by the CLR. Special threads include garbage collection threads (in concurrent and server garbage collection), debugger helper threads, finalizer threads, AppDomain unload threads, and thread pool timer threads.

Supported for Native AOT applications.
ThreadState < State value field > Displays the state of the thread. The value parameter is the value of the State field in the Threads report output.
Token2EE <module name> <token> Turns the specified metadata token in the specified module into a MethodTable structure or MethodDesc structure.

You can pass * for the module name parameter to find what that token maps to in every loaded managed module. You can also pass the debugger's name for a module, such as mscorlib or image00400000.
U [-gcinfo] [-ehinfo] [-n] <MethodDesc address> | <Code address> Displays an annotated disassembly of a managed method specified either by a MethodDesc structure pointer for the method or by a code address within the method body. The U command displays the entire method from start to finish, with annotations that convert metadata tokens to names.

The -gcinfo option causes the U command to display the GCInfo structure for the method.

The -ehinfo option displays exception information for the method. You can also obtain this information with the EHInfo command.

The -n option disables the display of source file names and line numbers. If the debugger has the option SYMOPT_LOAD_LINES specified, SOS looks up the symbols for every managed frame and, if successful, displays the corresponding source file name and line number. You can specify the -n option to disable this behavior.
VerifyHeap Checks the garbage collector heap for signs of corruption and displays any errors found.

Heap corruptions can be caused by platform invoke calls that are constructed incorrectly.

Supported for Native AOT applications.
VerifyObj <object address> Checks the object that is passed as an argument for signs of corruption. Only supported on Windows.
VMMap Traverses the virtual address space and displays the type of protection applied to each region. Only supported with Windbg.
VMStat Provides a summary view of the virtual address space, ordered by each type of protection applied to that memory (free, reserved, committed, private, mapped, image). The TOTAL column displays the result of the AVERAGE column multiplied by the BLK COUNT column. Only supported with Windbg.

Windows Debugger

You can also use the .NET debugger extensions by loading it into the WinDbg/dbg debugger and executing commands within the Windows debugger. The commands can be used on live processes or dumps.

Windbg should load the extension automatically whenever the process being debugged contains the .NET runtime (coreclr.dll or libcoreclr.so).

LLDB Debugger

For instructions on configuring the .NET debugger extensions for LLDB, see dotnet-debugger-extensions. The commands can be used on live processes or dumps.

By default you can reach all the commands by entering: sos [command_name]. However, the common commands have been aliased so that you don't need the sos prefix:

Command Function
analyzeoom Displays the info of the last OOM that occurred on an allocation request to the GC heap.
bpmd Creates a breakpoint at the specified managed method in the specified module.
clrmodules Lists the managed modules in the process.
clrstack Provides a stack trace of managed code only.
clrthreads Lists the managed threads that are running.
clru Displays an annotated disassembly of a managed method.
dbgout Enables/disables (-off) internal SOS logging.
dso Displays all managed objects found within the bounds of the current stack.
dumpalc Displays details about a collectible AssemblyLoadContext to which the specified object is loaded.
dumparray Displays details about a managed array.
dumpasync Displays info about async state machines on the garbage-collected heap.
dumpassembly Displays details about an assembly.
dumpclass Displays information about the EEClass structure at the specified address.
dumpconcurrentdictionary Displays concurrent dictionary content.
dumpconcurrentqueue Displays concurrent queue content.
dumpdelegate Displays information about a delegate.
dumpdomain Displays information about the all assemblies within all the AppDomains or the specified one.
dumpgcdata Displays information about the GC data.
dumpgen Displays heap content for the specified generation.
dumpheap Displays info about the garbage-collected heap and collection statistics about objects.
dumpil Displays the common intermediate language (CIL) that's associated with a managed method.
dumplock Displays information about System.Threading.Lock objects, such as those being held by threads (default), or those being waited upon by threads. This command is available in .NET debugger extensions only.
dumplog Writes the contents of an in-memory stress log to the specified file.
dumpmd Displays information about the MethodDesc structure at the specified address.
dumpmodule Displays information about the module at the specified address.
dumpmt Displays information about the method table at the specified address.
dumpobj Displays info the object at the specified address.
dumpruntimetypes Finds all System.RuntimeType objects in the GC heap and prints the type name and MethodTable they refer too.
dumpsig Dumps the signature of a method or field specified by <sigaddr> <moduleaddr>.
dumpsigelem Dumps a single element of a signature object.
dumpstack Displays a native and managed stack trace.
dumpstackobjects Displays all managed objects found within the bounds of the current stack.
dumpvc Displays info about the fields of a value class.
eeheap Displays info about process memory consumed by internal runtime data structures.
eestack Runs dumpstack on all threads in the process.
eeversion Displays information about the runtime and SOS versions.
ehinfo Displays the exception handling blocks in a JIT-ed method.
finalizequeue Displays all objects registered for finalization.
findappdomain Attempts to resolve the AppDomain of a GC object.
findroots Finds and displays object roots across GC collections.
gchandles Displays statistics about garbage collector handles in the process.
gcheapstat Displays statistics about garbage collector.
gcinfo Displays the JIT GC encoding for a method.
gcroot Displays info about references (or roots) to the object at the specified address.
gcwhere Displays the location in the GC heap of the specified address.
histclear Releases any resources used by the family of Hist commands.
histinit Initializes the SOS structures from the stress log saved in the debuggee.
histobj Examines all stress log relocation records and displays the chain of garbage collection relocations that may have led to the address passed in as an argument.
histobjfind Displays all the log entries that reference the object at the specified address.
histroot Displays information related to both promotions and relocations of the specified root.
histstats Displays stress log stats.
ip2md Displays the MethodDesc structure at the specified address in code that has been JIT-compiled.
listnearobj Displays the object preceding and succeeding the specified address.
loadsymbols Loads the .NET native module symbols.
logging Enables/disables internal SOS logging.
name2ee Displays the MethodTable and EEClass structures for the specified type or method in the specified module.
objsize Displays the size of the specified object.
parallelstacks Displays the merged threads stack similarly to the Visual Studio 'Parallel Stacks' panel.
pathto Displays the GC path from <root> to <target>.
pe Displays and formats fields of any object derived from the Exception class at the specified address.
printexception Displays and formats fields of any object derived from the Exception class at the specified address.
runtimes Lists the runtimes in the target or change the default runtime.
stoponcatch Target process will break the next time a managed exception is caught during execution.
setclrpath Sets the path to load coreclr dac/dbi files. setclrpath <path>.
sethostruntime Sets or displays the .NET runtime directory to use to run managed code in SOS.
setsymbolserver Enables the symbol server support.
setsostid Sets the current OS tid/thread index instead of using the one LLDB provides. setsostid <tid> <index>.
sos Executes various coreclr debugging commands. Use the syntax sos <command-name> <args>. For more information, see 'soshelp'.
soshelp Displays all available commands when no parameter is specified, or displays detailed help information about the specified command: soshelp <command>.
syncblk Displays the SyncBlock holder info.
taskstate Displays a Task state in a human readable format.
threadpool Displays info about the runtime thread pool.
threadpoolqueue Displays queued thread pool work items.
threadstate Pretty prints the meaning of a threads state.
timerinfo Displays information about running timers.
token2ee Displays the MethodTable structure and MethodDesc structure for the specified token and module.
traverseheap Writes out heap information to a file in a format understood by the CLR Profiler.
verifyheap Checks the GC heap for signs of corruption.
verifyobj Checks the object that is passed as an argument for signs of corruption.

Windbg/cdb example usage

Command Description
!dumparray -start 2 -length 5 -details 00ad28d0 Displays the contents of an array at the address 00ad28d0. The display starts from the second element and continues for five elements.
!dumpassembly 1ca248 Displays the contents of an assembly at the address 1ca248.
!dumpheap Displays information about the garbage collector heap.
!DumpLog Writes the contents of the in-memory stress log to a (default) file called StressLog.txt in the current directory.
!dumpmd 902f40 Displays the MethodDesc structure at the address 902f40.
!dumpmodule 1caa50 Displays information about a module at the address 1caa50.
!DumpObj a79d40 Displays information about an object at the address a79d40.
!DumpVC 0090320c 00a79d9c Displays the fields of a value class at the address 00a79d9c using the method table at the address 0090320c.
!eeheap -gc Displays the process memory used by the garbage collector.
!finalizequeue Displays all objects scheduled for finalization.
!findappdomain 00a79d98 Determines the application domain of an object at the address 00a79d98.
!gcinfo 5b68dbb8 Displays all garbage collector handles in the current process.
!name2ee unittest.exe MainClass.Main Displays the MethodTable and EEClass structures for the Main method in the class MainClass in the module unittest.exe.
!token2ee unittest.exe 02000003 Displays information about the metadata token at the address 02000003 in the module unittest.exe.

LLDB example usage

Command Description
dumparray -start 2 -length 5 -details 00ad28d0 Displays the contents of an array at the address 00ad28d0. The display starts from the second element and continues for five elements.
dumpassembly 1ca248 Displays the contents of an assembly at the address 1ca248.
dumpheap Displays information about the garbage collector heap.
dumplog Writes the contents of the in-memory stress log to a (default) file called StressLog.txt in the current directory.
dumpmd 902f40 Displays the MethodDesc structure at the address 902f40.
dumpmodule 1caa50 Displays information about a module at the address 1caa50.
dumpobj a79d40 Displays information about an object at the address a79d40.
dumpvc 0090320c 00a79d9c Displays the fields of a value class at the address 00a79d9c using the method table at the address 0090320c.
eeheap -gc Displays the process memory used by the garbage collector.
findappdomain 00a79d98 Determines the application domain of an object at the address 00a79d98.
gcinfo 5b68dbb8 Displays all garbage collector handles in the current process.
name2ee unittest.exe MainClass.Main Displays the MethodTable and EEClass structures for the Main method in the class MainClass in the module unittest.exe.
token2ee unittest.exe 02000003 Displays information about the metadata token at the address 02000003 in the module unittest.exe.
clrthreads Displays the managed threads.

See also