_veli,
$WAKEs can come from anywhere. If your application cares about being woken up from the "right" place, you need to code some mechanism to confirm the wakeup.
Properly written code should be able to handle any number of $WAKEs without any problems. For example, RUN/INTERVAL=delta-time will cause a $WAKE at delta-time intervals. At worst, this should cause your process to consume a bit more CPU time.
This is a general principle in any code that deals with events signalled by $WAKE, $SETEF or any other "broadcast" mechanism. You need something that positively identifies that the specific event you're waiting for has occurred. All asynchronous system services use an IOSB for this purpose.
For example:
Declare a flag variable:
global woken
Sleep code:
woken=false
...
code to "prime" the event
...
while not woken do
$hiber()
end while
$wake(,)
Wakeup code
woken=true
$wake(,)
This assumes the $WAKEs will come from the process itself. If they're from an external process, the flag is a bit harder to implement. Sometimes the confirmation can be implicit, for example, the presence of a packet on a work queue. Also note that there is an extra $WAKE after the sleep loop. That's because you may have consumed someone else's $WAKE while iterating the loop. The extra $WAKE also assumes that OTHER people's code can also deal with spurious $WAKEs.
Also remember that if there is a pending $WAKE, $HIBER will return immediately. Only one pending $WAKE is "remembered". If it's important that your code really sleeps, you can code it like this:
$WAKE(,) ! Force pending $WAKE
$HIBER() ! Consume pending $WAKE
$HIBER() ! Sleep
$WAKE(,)
A crucible of informative mistakes
