?
Solved

VC++ Debugger DLL Unloaded??

Posted on 2006-07-06
2
Medium Priority
?
481 Views
Last Modified: 2008-03-10
On the output of an application that is running in debug mode.  It will show when the dll's are loading and unloading.  Is this accurate?  When the Output section shows a.dll unloaded.  Is a.dll completely finished unloading.  Is it starting to unload.  If an exception happens and the output says a.dll unloaded is it safe to assume the exception has nothing to do with a.dll since it is 'unloaded'.  

Is any of this accurate.  Or is the debugging output not an accurate measure for when dll's are loaded and unloaded?
0
Comment
Question by:cophi
[X]
Welcome to Experts Exchange

Add your voice to the tech community where 5M+ people just like you are talking about what matters.

  • Help others & share knowledge
  • Earn cash & points
  • Learn & ask questions
  • 2
2 Comments
 
LVL 86

Accepted Solution

by:
jkr earned 2000 total points
ID: 17052749
Yes, that is correct. When the debugger reports a DLL as 'unloaded', it's reference counter (which is increased with 'LoadLibrary()' and decreased with 'FreeLibrary()') has dropped to zero and the DLL is unmapped from the process' memory.

Yet the exception might have to do with some code in the process trying to access code or data in the DLL that has previously been unloaded.

BTW, you might want to double-check that with the DependencyWalker (www.dependencywalker.com) in 'Profile Mode'. The log file that it creates is veryuseful in diagnosing faulty behaviour.
0
 
LVL 86

Expert Comment

by:jkr
ID: 17052886
As a side note - these messages are generated based on a 'UNLOAD_DLL_DEBUG_EVENT' that the debugger receives through 'WaitForDebugEvent()', see http://msdn.microsoft.com/library/en-us/debug/base/debug_event_str.asp ("DEBUG_EVENT") and http://msdn.microsoft.com/library/en-us/debug/base/unload_dll_debug_info_str.asp ("UNLOAD_DLL_DEBUG_INFO").
0

Featured Post

On Demand Webinar: Networking for the Cloud Era

Did you know SD-WANs can improve network connectivity? Check out this webinar to learn how an SD-WAN simplified, one-click tool can help you migrate and manage data in the cloud.

Question has a verified solution.

If you are experiencing a similar issue, please ask a related question

Article by: SunnyDark
This article's goal is to present you with an easy to use XML wrapper for C++ and also present some interesting techniques that you might use with MS C++. The reason I built this class is to ease the pain of using XML files with C++, since there is…
Often, when implementing a feature, you won't know how certain events should be handled at the point where they occur and you'd rather defer to the user of your function or class. For example, a XML parser will extract a tag from the source code, wh…
The viewer will learn how to clear a vector as well as how to detect empty vectors in C++.
The viewer will be introduced to the technique of using vectors in C++. The video will cover how to define a vector, store values in the vector and retrieve data from the values stored in the vector.
Suggested Courses

765 members asked questions and received personalized solutions in the past 7 days.

Join the community of 500,000 technology professionals and ask your questions.

Join & Ask a Question