Re: [Mingw-users] Mingw, COM, JNI, MFC and threads

[Paul G. <pga...@te...>]

Hi folks,

On 8 Dec 2000, at 9:10, the Illustrious niceguy wrote:

> Yes, I am trying to combine all the items in the subject in a
> single project.  :)

> The problem:
> 
> When I start the JUnit application and attempt to run tests, I
> get a spectacular crash from the MS C++ runtime.  After much
> fiddling and debugging, I have determined that the crash only
> happens when a thread other than the the main thread of the Java
> application makes a call to the COM interface of the CAD
> application.  If I start the JUnit program and pass in the name
> of a test to run, the test completes successfully.  If I select
> the test from a list in the GUI and try to run it, the crash
> occurs, because the code is running in the Java event dispatch
> thread.  If I create a new thread from inside the main thread and
> run tests, the crash occurs.  So it is definitely thread-related.
>  This problem essentially means that no Java application with a
> GUI can be used to interact with the CAD application, which is a
> restriction I would rather not have, for obvious reasons.
> 
> The question:
> 
> Are there any specific issues related to COM and threads in the
> context of a DLL compiled with Mingw?  Is there anything special
> I should be doing when compiling and/or linking?

	Hmm...will give this a shot by itemizing a few things to check -
- Bear in mind that this is mostly speculation and deduction 
based on your post.

	a) verify that your mingw app is being compiled with -mthreads 
(this provides a level of thread safety that doesn't exist when -
mthreads is not used)

	b) verify that your mingw app also has the -fvtable-thunks 
enabled (this is to insure that the COM stuff is being 
initialized properly)

	c) verify that you have -fnative-structs defined

	d) If the CAD program was generated using msvc/c++, verify that 
you are using an MS type of .dll as  opposed to a mingw type of 
.dll.  They are different.  -fnative-structs works to help 
minimize the conflicts between the mingw .dll and the MS .dlls.

	Hope this helps.

	Peace,

		Paul G.

> 
> Any/All assistance appreciated,
> 
> Jim S.
> 
> _______________________________________________
> MinGW-users mailing list
> Min...@li...
> 
> You may change your MinGW Account Options at:
> http://lists.sourceforge.net/mailman/listinfo/mingw-users
> 




Nothing real can be threatened.
    Nothing unreal exists.