So there is one solution that comes to mind and meets the following goals:
- Size of the binary would increase by around 300k
- Ability to generate mdump files in a fatale crash.
- Ability to do "pause" the app do a dump, and contiune would be a bonus
I'll give this requirement a complete unknown:
- No way i can port that app to run inn windows mobile.
So what's the solution?
Integrate the required parts you need from the Microsoft Sample for MDbg.exe to provide you with a 'just-in-time' debugger that attaches, dumps, and detaches from the crashing process.
Step 1 - Start by downloading the source code to the mdbg from here: http://www.microsoft.com/downloads/en/details.aspx?FamilyID=38449a42-6b7a-4e28-80ce-c55645ab1310&DisplayLang=en
Step 2 - Create a 'crash' handler that spawns a debugger process and waits for completion. I used the following few lines of code to re-launch the same exe with a few extra arguments to invoke the debugger and output an xml file to std::out.
string tempFile = Path.GetTempFileName();
Mutex handle = new Mutex(true, typeof(Program).Namespace + "-self-debugging");
try
{
Process pDebug = Process.Start(typeof(Program).Assembly.Location,
"debug-dump " + Process.GetCurrentProcess().Id + " " + tempFile);
if (pDebug != null)
pDebug.WaitForExit();
}
catch { }
finally
{
handle.ReleaseMutex();
}
Console.WriteLine(File.ReadAllText(tempFile));
Step 3 - Write the debug dump routine, this can be in the same exe or in a different exe. You will need to reference (or include the source from) the 'raw', 'corapi', and 'mdbgeng' modules from the sample. Then add a few lines to your Main():
public static void Main(string[] args)
{
if (args.Length > 0 && args[0] == "debug-dump")
{ //debug-dump process by id = args[1], output = args[2]
using (XmlTextWriter wtr = new XmlTextWriter(args[2], Encoding.ASCII))
{
wtr.Formatting = Formatting.Indented;
PerformDebugDump(Int32.Parse(args[1]), wtr);
}
return;
}
//... continue normal program execution
}
static void PerformDebugDump(int process, XmlWriter x)
{
x.WriteStartElement("process");
x.WriteAttributeString("id", process.ToString());
x.WriteAttributeString("time", XmlConvert.ToString(DateTime.Now, XmlDateTimeSerializationMode.RoundtripKind));
MDbgEngine e = new MDbgEngine();
MDbgProcess me = e.Attach(process);
me.Go().WaitOne();
try
{
x.WriteStartElement("modules");
foreach (MDbgModule mod in me.Modules)
x.WriteElementString("module", mod.CorModule.Name);
x.WriteEndElement();
foreach (MDbgThread thread in me.Threads)
{
x.WriteStartElement("thread");
x.WriteAttributeString("id", thread.Id.ToString());
x.WriteAttributeString("number", thread.Number.ToString());
int ixstack = -1;
foreach (MDbgFrame frame in thread.Frames)
{
x.WriteStartElement("frame");
x.WriteAttributeString("ix", (++ixstack).ToString());
x.WriteAttributeString("loc", frame.ToString(String.Empty));
string valueText = null;
x.WriteStartElement("args");
try
{
foreach (MDbgValue value in frame.Function.GetArguments(frame))
{
x.WriteStartElement(value.Name);
x.WriteAttributeString("type", value.TypeName);
try { x.WriteAttributeString("value", value.GetStringValue(1, false)); }
finally { x.WriteEndElement(); }
}
}
catch { }
x.WriteEndElement();
x.WriteStartElement("locals");
try
{
foreach (MDbgValue value in frame.Function.GetActiveLocalVars(frame))
{
x.WriteStartElement(value.Name);
x.WriteAttributeString("type", value.TypeName);
try { x.WriteAttributeString("value", value.GetStringValue(1, false)); }
finally { x.WriteEndElement(); }
}
}
catch { }
x.WriteEndElement();
x.WriteEndElement();
}
x.WriteEndElement();
}
}
finally
{
me.Detach().WaitOne();
}
x.WriteEndElement();
}
Example Output
<process id="8276" time="2010-10-18T16:03:59.3781465-05:00">
<modules>
<module>C:\Windows\assembly\GAC_32\mscorlib\2.0.0.0__b77a5c561934e089\mscorlib.dll</module>
...etc
</modules>
<thread id="17208" number="0">
<frame ix="0" loc="System.Windows.Forms.Application.ComponentManager.System.Windows.Forms.UnsafeNativeMethods.IMsoComponentManager.FPushMessageLoop (source line information unavailable)">
<args>
<this type="System.Windows.Forms.Application.ComponentManager" value="System.Windows.Forms.Application.ComponentManager
 oleComponents=System.Collections.Hashtable
 cookieCounter=1
 activeComponent=System.Windows.Forms.Application.ThreadContext
 trackingComponent=<null>
 currentState=0" />
<dwComponentID type="N/A" value="<N/A>" />
<reason type="System.Int32" value="-1" />
<pvLoopData type="System.Int32" value="0" />
</args>
<locals>
<local_0 type="System.Int32" value="0" />
<local_1 type="System.Boolean" value="True" />
<local_2 type="System.Windows.Forms.UnsafeNativeMethods.IMsoComponent" value="<null>" />
<local_3 type="N/A" value="<N/A>" />
<local_4 type="N/A" value="<N/A>" />
<local_5 type="N/A" value="<N/A>" />
<local_6 type="System.Windows.Forms.Application.ThreadContext" value="System.Windows.Forms.Application.ThreadContext
 contextHash=System.Collections.Hashtable
 tcInternalSyncObject=System.Object
 totalMessageLoopCount=1
 baseLoopReason=-1
 currentThreadContext=System.Windows.Forms.Application.ThreadContext
 threadExceptionHandler=System.Threading.ThreadExceptionEventHandler
 idleHandler=<null>
 enterModalHandler=<null>
 leaveModalHandler=<null>
 applicationContext=System.Windows.Forms.ApplicationContext
 parkingWindow=<null>
 marshalingControl=System.Windows.Forms.Application.MarshalingControl
 culture=<null>
 messageFilters=<null>
 messageFilterSnapshot=<null>
 handle=912
 id=17208
 messageLoopCount=1
 threadState=1
 modalCount=0
 activatingControlRef=<null>
 componentManager=System.Windows.Forms.Application.ComponentManager
 externalComponentManager=False
 fetchingComponentManager=False
 componentID=1
 currentForm=Program.MainForm
 threadWindows=<null>
 tempMsg=System.Windows.Forms.NativeMethods.MSG
 disposeCount=0
 ourModalLoop=False
 messageLoopCallback=<null>
 __identity=<null>" />
<local_7 type="N/A" value="<N/A>" />
<local_8 type="N/A" value="<N/A>" />
<local_9 type="N/A" value="<N/A>" />
<local_10 type="N/A" value="<N/A>" />
<local_11 type="N/A" value="<N/A>" />
<local_12 type="N/A" value="<N/A>" />
<local_13 type="System.Boolean" value="False" />
<local_14 type="System.Windows.Forms.NativeMethods.MSG[]" value="array [1]
 [0] = System.Windows.Forms.NativeMethods.MSG" />
</locals>
</frame>
<frame ix="1" loc="System.Windows.Forms.Application.ThreadContext.RunMessageLoopInner (source line information unavailable)">
<args>
<this type="System.Windows.Forms.Application.ThreadContext" value="System.Windows.Forms.Application.ThreadContext
 contextHash=System.Collections.Hashtable
 tcInternalSyncObject=System.Object
 totalMessageLoopCount=1
 baseLoopReason=-1
 currentThreadContext=System.Windows.Forms.Application.ThreadContext
 threadExceptionHandler=System.Threading.ThreadExceptionEventHandler
 idleHandler=<null>
 enterModalHandler=<null>
 leaveModalHandler=<null>
 applicationContext=System.Windows.Forms.ApplicationContext
 parkingWindow=<null>
 marshalingControl=System.Windows.Forms.Application.MarshalingControl
 culture=<null>
 messageFilters=<null>
 messageFilterSnapshot=<null>
 handle=912
 id=17208
 messageLoopCount=1
 threadState=1
 modalCount=0
 activatingControlRef=<null>
 componentManager=System.Windows.Forms.Application.ComponentManager
 externalComponentManager=False
 fetchingComponentManager=False
 componentID=1
 currentForm=Program.MainForm
 threadWindows=<null>
 tempMsg=System.Windows.Forms.NativeMethods.MSG
 disposeCount=0
 ourModalLoop=False
 messageLoopCallback=<null>
 __identity=<null>" />
<reason type="System.Int32" value="-1" />
<context type="System.Windows.Forms.ApplicationContext" value="System.Windows.Forms.ApplicationContext
 mainForm=Program.MainForm
 userData=<null>
 ThreadExit=System.EventHandler" />
</args>
<locals>
<local_0 type="System.Windows.Forms.Form" value="<null>" />
<local_1 type="System.Boolean" value="False" />
<local_2 type="N/A" value="<N/A>" />
<local_3 type="N/A" value="<N/A>" />
<local_4 type="N/A" value="<N/A>" />
</locals>
</frame>
... etc
</thread>
</process>
Since you have the full power of a debugger there is nothing stopping you from writing as much or as little as you like, but the above example should get you started.
UPDATE
This works with the .Net 2.0 and/or 3.5 runtime without any further dependencies.
This can debug .Net 2.0/3.5 code running in a .Net 4.0 process; however, it does not work with 4.0 (yet).
For 4.0 CLR see this post:
http://blogs.msdn.com/b/rmbyers/archive/2008/10/27/icordebug-re-architecture-in-clr-4-0.aspx
