Re: [ros-dev] Re: [ros-svn] [ion] 20554: - Fix shamefully dangerously broken Work Thread/Queue/Item implementation:

[Hartmut Birr]

Alex Ionescu wrote:
>   Hartmut Birr wrote:
>
> >   Hi,
> >
> >  there are three places in the kernel, which does remove wait blocks.
> >  They are in KiAbortWaitThread, KiInsertQueue and KiBlockThread. Only in
> >  KiBlockThread, Thread->WaitBlockList is  set to NULL. Is this the
> >  problem?
> >
> >  - Hartmut
> >   
> >  
>  Hi,
>
>  I have been reading Windows Internals II and Windows Internals 4th
>  Edition and I see that the wait blocks are actually supposed to be a
>  circular list... so there should never really be any "NULL". It's
>  possible I based some previous code on this knowledge, which is now
>  conflicting with the ROS implementation of a null-terminated list. I
>  will change the wait code to use circular lists as documented and post
>  a patch.
>
>  Best regards,
>  Alex Ionescu
>  
I think, the real problem isn't if the list is NULL terminated or if the
WaitBlockList entry from thread is NULL. The real problem is,
KiAbortWaitThread is called for a thread which does not waiting.

- Hartmut