[Ace-users] [ace-users] Why the spawned thread must be waited?

Douglas C. Schmidt schmidt at dre.vanderbilt.edu
Thu Nov 1 11:23:58 CDT 2007

Hi John,

>    I am developing a windows client with MFC and ACE. For user-
>friendliness, the request to the server can be  cancelled. I put two
>threads in the client, one is for UI, the other is for network
>    I want to use the active object pattern to handle the net
>1. The MFC message handler received a button-click event
>2. The message handler creates an agent proxy and an
>ACE_Future_Observer object
>   (exactly like %ACE_ROOT%/examples/apg/active_objects/AO2.cpp)
>3. When the request completed, the ACE_Future_Observer object would
>get the result, then notify the UI thread.
>    Now I face a problem: if I don't call ACE_Thread_Manager::instance
>()->wait(), the spawned thread would crash; but when I call it, the UI
>thread would be blocked (and it would succeed to get the result).
>    Why must we wait the spawned thread?
>    When activated it, I used the flag (THR_NEW_LWP | THR_DETACHED).

It's not clear what version of ACE you are using.  Perhaps you have an
old version with a bug in it?  To ensure that we have proper
version/platform/compiler information, please make sure you fill out
the appropriate problem report form (PRF), which is in


or in


in older versions of ACE+TAO.  Make sure to include this information
when asking any questions about ACE+TAO since otherwise we have to
"guess" what version/platform/compiler/options you've using, which is
very error-prone and slows down our responsiveness.  If you don't use
the PRF, therefore, it is less likely that someone from the core
ACE+TAO developer team will be able to answer your question.
Naturally, we encourage and appreciate other members of the ACE+TAO
user community who can respond to questions that they have the answers


Dr. Douglas C. Schmidt                       Professor and Associate Chair
Electrical Engineering and Computer Science  TEL: (615) 343-8197
Vanderbilt University                        WEB: www.dre.vanderbilt.edu/~schmidt
Nashville, TN 37203                          NET: d.schmidt at vanderbilt.edu

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