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SubjectRe: sleep for ever ?
Hello, there.

Bo Yang wrote:
> Hi ,
> Take a look at following code :
>
> DECLARE_WAITQUEUE(wait, current);
>
> add_wait_queue(q, &wait);
> while (!condition) {
> /* if there is an interrupt here , and the interrupt
> is just the one the sleeping process wait
> for , is this process sleep for the interrupt
> for ever ?*/
> set_current_state(TASK_INTERRUPTIBLE);
> if (signal_pending(current))
> /* handle signal */
> schedule();
> }
> set_current_state(TASK_RUNNING);
> remove_wait_queue(q, &wait);
>
> Suppose the process just want to sleep for an hardware
> event , but before the set_current_state() call , the event
> come , is the process sleep for ever ?

I guess you already know it but please try not to post the same message
multiple times.

And, yes, you're responsible to set task state *before* testing for the
sleeping condition and sleep. In the above code, you can lose the wake
up event and thus sleep indefinitely.

--
tejun
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