Enable objsize in lldb and SOS debugger

documentation/sos-debugging-extension.md

@@ -39,8 +39,8 @@ importance. Shortcut names for popular functions are listed in parenthesis. Type
     DumpHeap (dumpheap)                DumpStack (dumpstack)
     DumpVC                             EEStack (eestack)
     GCRoot (gcroot)                    CLRStack (clrstack)
-    PrintException (pe)                GCInfo
-                                       EHInfo
+    ObjSize                            GCInfo
+    PrintException (pe)                EHInfo
                                        bpmd (bpmd)
 
     Examining CLR data structures      Diagnostic Utilities
@@ -110,6 +110,7 @@ importance. Shortcut names for popular functions are listed in parenthesis. Type
 |**HistRoot** *\<root>*|Displays information related to both promotions and relocations of the specified root.<br /><br /> 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.|
 |**Name2EE** (**name2ee**) \<*module name*> \<*type or method name*><br /><br /> -or-<br /><br /> **Name2EE** \<*module name*>**!**\<*type or method name*>|Displays the `MethodTable` structure and `EEClass` structure for the specified type or method in the specified module.<br /><br /> The specified module must be loaded in the process.<br /><br /> To get the proper type name you can browse the module by using the an IL reflection tool like Ildasm or ILSpy. 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`.<br /><br /> This command supports the Windows debugger syntax of <`module`>`!`<`type`>. The type must be fully qualified.|
+|**ObjSize** [\<*Object address*>] &#124; [**-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.<br /><br /> The **-aggregate** option can be used in conjunction 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.|
 |**PrintException** [**-nested**] [**-lines**] [\<*Exception object address*>]<br /><br /> -or-<br /><br /> **PE** [**-nested**] [\<*Exception object address*>]|Displays and formats fields of any object derived from the <xref:System.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.<br /><br /> The **-nested** option displays details about nested exception objects.<br /><br /> The **-lines** option displays source information, if available.<br /><br /> You can use this command to format and view the `_stackTrace` field, which is a binary array.|
 |**SyncBlk** [**-all** &#124; \<*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.<br /><br /> 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.|
 |**SOSFlush**|Flushes an internal SOS cache.|

src/SOS/Strike/sos_unixexports.src

@@ -48,6 +48,7 @@ HistStats
 IP2MD
 logging
 Name2EE
+ObjectSize
 PrintException
 PathTo
 StopOnCatch

src/SOS/Strike/sosdocsunix.txt

@@ -32,7 +32,8 @@ DumpHeap (dumpheap)                EEStack (eestack)
 DumpVC                             ClrStack (clrstack)
 FinalizeQueue (finalizequeue)      GCInfo
 GCRoot (gcroot)                    EHInfo
-PrintException (pe)                bpmd (bpmd)
+ObjSize                            bpmd (bpmd)
+PrintException (pe)
 
 Examining CLR data structures      Diagnostic Utilities
 -----------------------------      -----------------------------
@@ -487,6 +488,44 @@ objects, there is a -nostacks option.
 The -all option forces all roots to be displayed instead of just the unique roots.
 \\
 
+COMMAND: objsize.
+ObjSize [<Object address>]
+
+With no parameters, ObjSize lists the size of all objects found on managed 
+threads. It also enumerates all GCHandles in the process, and totals the size 
+of any objects pointed to by those handles. In calculating object size, 
+ObjSize includes the size of all child objects in addition to the parent.
+
+For example, DumpObj lists a size of 20 bytes for this Customer object:
+
+    (lldb) dumpobj a79d40
+    Name: Customer
+    MethodTable: 009038ec
+    EEClass: 03ee1b84
+    Size: 20(0x14) bytes
+     (C:\pub\unittest.exe)
+    Fields:
+          MT    Field   Offset                 Type       Attr    Value Name
+    009038ec  4000008        4                CLASS   instance 00a79ce4 name
+    009038ec  4000009        8                CLASS   instance 00a79d2c bank
+    009038ec  400000a        c       System.Boolean   instance        1 valid
+
+but ObjSize lists 152 bytes:
+
+    (lldb) ObjSize a79d40
+    sizeof(00a79d40) =      152 (    0x98) bytes (Customer)
+
+This is because a Customer points to a Bank, has a name, and the Bank points to
+an Address string. You can use ObjSize to identify any particularly large 
+objects, such as a managed cache in a web server.
+
+While running ObjSize with no arguments may point to specific roots that hold 
+onto large amounts of memory it does not provide information regarding the 
+amount of managed memory that is still alive.  This is due to the fact that a 
+number of roots can share a common subgraph, and that part will be reported in 
+the size of all the roots that reference the subgraph.
+\\
+
 COMMAND: pe.
 COMMAND: printexception.
 PrintException [-nested] [-lines] [-ccw] [<Exception object address>] [<CCW pointer>]

src/SOS/Strike/strike.cpp

@@ -11985,10 +11985,8 @@ DECLARE_API(StopOnException)
 \**********************************************************************/
 DECLARE_API(ObjSize)
 {
-#ifndef FEATURE_PAL
     INIT_API();
     MINIDUMP_NOT_SUPPORTED();
-    ONLY_SUPPORTED_ON_WINDOWS_TARGET();
 
     BOOL dml = FALSE;
     StringHolder str_Object;
@@ -12031,10 +12029,6 @@ DECLARE_API(ObjSize)
         ExtOut("sizeof(%p) = %d (0x%x) bytes (%S)\n", SOS_PTR(obj), size, size, methodTable.GetName());
     }
     return Status;
-#else
-    return E_NOTIMPL;
-#endif
-
 }
 
 #ifndef FEATURE_PAL

src/SOS/lldbplugin/soscommand.cpp

@@ -190,6 +190,7 @@ sosCommandInitialize(lldb::SBDebugger debugger)
     g_services->AddCommand("histobj", new sosCommand("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.");
     g_services->AddCommand("histobjfind", new sosCommand("HistObjFind"), "Displays all the log entries that reference an object at the specified address.");
     g_services->AddCommand("histroot", new sosCommand("HistRoot"), "Displays information related to both promotions and relocations of the specified root.");
+    g_services->AddCommand("objsize", new sosCommand("ObjSize"), "Displays the size of the specified object.");
     g_services->AddCommand("setclrpath", new sosCommand("SetClrPath"), "Set the path to load the runtime DAC/DBI files.");
     g_services->AddCommand("setsymbolserver", new sosCommand("SetSymbolServer"), "Enables the symbol server support ");
     g_services->AddCommand("sympath", new sosCommand("SetSymbolServer", "-sympath"), "Add server, cache and directory paths in the Windows symbol path format.");