Re: Timer resolution for sys$setimr() ?

On 12/4/2024 10:01 AM, Arne Vajhøj wrote:

On 12/4/2024 8:37 AM, Simon Clubley wrote:

What is the actual resolution of timer events queued using the
sys$setimr() system service ?
>
NOTE: this is about when the timer becomes eligible to fire, not when
it actually does, given that VMS is not a hard RTOS.
>
The base VMS time format is in 100ns units, but I couldn't see anything
about the units actually used when firing timer events. Is it the same
as the hopeless terminal driver timeouts, or is it 100ns, or is it
something in between ?

 IDS VMS Alpha 1.5 (30 years old!) says:
 <quote>

...

</quote>
 which I read as if that on Alpha then VMS checks for SYS$SETIMR
AST's to queue every 1 millisecond.
 No guarantees when the AST's will actually run.
 And some things may have changed in newer VMS versions and
newer hardware.

https://hunter.goatley.com/writing-vms-privileged-code/part-v-timer-queues/
has a lot of details.
But is about the same age as the old IDS.
Arne