Managed Dump debugging support for Visual Studio and ICorDebug

This is the longest I’ve gone without blogging, but our PDC announcements have stuff way too cool to stay quiet about.

If you saw PDC, you’ve head that the CLR Debugging API, ICorDebug, will support dump-debugging. This enables any ICorDebug-based debugger (including Visual Studio and MDbg) to debug dump-files of .NET applications. The coolness goes well beyond that, but dump-debugging is just the easiest feature to describe.

This was not an overnight feature, and required some major architectural changes to be plumbed through the entire system.  Specifically, when dump-debugging, there’s no ‘live’ debuggee, so you can’t rely on a helper-thread running in the debuggee process to service debugging requests anymore, so you need a completely different model.

Rick Byers has an excellent description of the ICorDebug re-architecture in CLR 4.0.  He also describes some of the other advancements in the CLR Tools API space. Go read them.

Comments (4)

  1. MD says:

    Sorry Mike I am writing my comment to this  post .. as comment to earlier post is stoped My question is realted to post "Simple harness to print exceptions in an app"

    Is there any way to detach attached process in that example ?

  2. MD –

    ICorDebug supports detaching the debugger.

    The best place to ask more about that would be at this forums (which has an excellent answer rate):

    Other random detach trivia:

  3. Tanveer Badar says:

    Hello Mike. First of all, I really enjoy reading your blog. Keep up the (very) good work.

    During one of my ‘weird testing of a random application’ sessions, I came across a crash in mdbg.

    Here are the details on lady bug:

    In short, attach two instances of mdgb to each other in a cycle. Now close the console window, it will crash. All attempts to attach VS or windbg fail.

    Can you kindly shed some light on what is going on in this crash?

  4. Tanveer –

    can you post the MDbg issue to the .NET tools forum at:

    The forum has an excellent answer rate and should be able to shed a lot of light on what’s going on.