At 5:00 PM -0500 2000/01/28, Michael Theroux wrote:
>I was reading in the SDK about procedure alarms, and wrote a couple
>of sample apps to try them out, however, I am curious on how they
>work. Is this done through a context switch-like operation? Is it
>a special type of event? With regular alarms, no other alarms will
>trigger until your alarm is processed. Is this also true for procedure
>alarms? I am particularly curious because procedure alarms seem to
>execute in the scope of a currently running application. If anyone
>can point me to some additional info on this, it would be greatly
>appreciated.
Currently, all alarms are triggered from within the EvtGetEvent call of the active
application, while the UI task is executing (i.e. alarms are not preemptive). There is
no behavioral difference between launch code based alarms and procedure based alarms
other than one is notified by launch code and the other by function pointer.
Display-only launch code based alarms may also be triggered from within the
SysHandleEvent call of the current application via a vchrAlarm virtual keydown event.
UI may be invoked from either callback mechanism. Just be aware that the callback may
occur while some other application is active, therefore broadcast launch code rules
apply for both alarm types.
Hope that helps...
Regards,
Jim Schram
3Com/Palm Computing
Partner Engineering
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