mp26 at os.inf.tu-dresden.de
Wed Feb 23 19:41:40 CET 2005
Ronald Aigner wrote:
> To imitate the concurrent waiting for an IPC or timer event one could set
> up a timer with the kernel and inculde the "timer-source" into the receive
> scope of the wait IPC. Timer events can be dropped if the receiver is not
> ready. This would also simplify the tasks using IPC timeouts as timer
> event source.
I see one problem with this:
I use finite timeouts in a library emulating keyboard repeat behaviour
(you press the key -> one press event is generated, you keep the key
pressed -> after 250 ms another event is generated every 100 ms until
you release the key).
This is implemented with IPC-Recv from an event thread with the timeouts
The setup and start of the timer and the ipc operation in this scenario
is atomic. If I would have to setup and start the timer independently
of the IPC I could be interupted and/or delayed in-between if no other
meassures (e.g. delayed preemption) would be taken.
There could be similar more critical examples (although I think that a
spongy keyboard is bad enough).
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