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Re: Is this a bug


TomChen <chenqy_79@163.com> writes:

> Hi All,
> 
> Kernel package src/sched/mlqueue.cxx
> in function Cyg_ThreadQueue_Implementation::enqueue(Cyg_Thread *thread) ,
> 
> When there is more than one thread in the queue and the priority is
> neither higer than the head nor lower than the tail, we have to search
> the queue to find the place. The code for this is:
> 
> Cyg_Thread *qtmp = get_tail();
> while ( thread->priority > qtmp->priority)
>     qtmp = qtmp->get_prev();
> qtmp->append( thread );
> 
> I think this should be:
> 
> Cyg_Thread *qtmp = get_tail();
> while ( thread->priority *<* qtmp->priority)
>     qtmp = qtmp->get_prev();
> qtmp->append( thread );

I believe the original code it correct.

Remember that the priorities go from 0=highest to 31=lowest. So the
loop spins while the thread priorities are numerically greater than
the one we want to insert. Once we find one that is less than or equal
we break out and install the new thread just after it.

-- 
Nick Garnett                    eCos Kernel Architect
http://www.ecoscentric.com/     The eCos and RedBoot experts


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