Re: notifying particular thread to wake up.
Rupesh wrote On 09/25/07 17:37,:
Is there any way to notify a particular thread to wake up? All the
waiting threads are same priority.
What are they waiting for?
If they are waiting on condition variables, then yes:
call pthread_cond_broadcast() on all the condvars, which
will cause all the waiting threads to awaken, including
the one you care about (if it was among those waiting).
But perhaps you want to awaken the designated thread
without awakening any others? If so, the answer is no.
Threads waiting on condvars may awaken at any time, with
or without a good reason. You can ensure that at least
one awakens, but you cannot prevent others from doing so,
too.
You could set a variable specifying "Thread T3 should
run" before calling pthread_cond_signal() or _broadcast().
Unintended threads might or might not wake up, but each
can test your variable and go right back to sleep again
unless it's T3.
The interesting question is: Why do you care which
thread wakes up? It usually shouldn't matter.
--
Eric.Sosman@sun.com