>>>>> "mab" == mark a biggar <[EMAIL PROTECTED]> writes:
mab> You wrote: >> i don't think there is a need for all those variants. why would alarm >> need any special opcode when it is just a timer with a delay of abs_time >> - NOW? let the coder handle that and lose the extra op codes. mab> No, you don't want to do it that way. Becasue you want to make mab> the latency between getting the abs_time, doing the substract and mab> actually setting up the time as small, as possible you almost mab> have to do this operation as a builtin op. In fact you can argue mab> that you want to lock out async events while doing it as well. i always assume timers to trigger after a specified delay. accuracy of delivery (latency) is silly to worry about in perl for granularities of more than about .05 seconds or so. building a very fine grained accurate real time system in perl makes little sense to me. so i usually don't worry about who does the delta calculation and the slight amount of delay it takes. it will be much smaller than the typical granularity of the timings anyway. yes, i can see how an slow async event between the delta calc and the actual event creation could cause a problem. a way around it is to use a cronlike thing which has an interval timer and checks for the actual absolute time and not some precalculated (and possibly way off) delta. again, i assume event timers are minimum delay devices and i never assume any sort of decent latency. you get called some time AFTER the delay is over. so absolute times should be done with a repeat timer set for the actual granularity you want. and most absolute timers are in 1 minute or more granularites (e.g. cron). so i would never use the absolute timer in parrot since i couldn't trust it any more than i can trust a repeated interval timer. but while i can synchronize interval timers to the real clock, i can't adjust a miscalculated absolute timer. uri -- Uri Guttman ------ [EMAIL PROTECTED] -------- http://www.stemsystems.com --Perl Consulting, Stem Development, Systems Architecture, Design and Coding- Search or Offer Perl Jobs ---------------------------- http://jobs.perl.org
