[Embedlets-dev] Re: Timer Service
Status: Alpha
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From: Andrzej J. T. <an...@ch...> - 2003-03-16 20:49:55
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Brill: > Is the timer service you have set up emulating a hardware timer, or is it a > service in general? (I think a "service in general" would be useful). It is a general service and is not intended to emulate or otherwise replace hardware-based timers. Due to the design of the service, and the facilities provided by the underlying Java implementations, the Timer service can only provide an "approximation" of the timer duration that a component (eg. Embedlet) developer may request. So a 100 ms. repetitive timer may fire at 150 ms, 120 ms, 100ms etc. The timer service should be used for situations where the absolute timer interval is not overly critical. Hardware (and interrupt based timers) are typically used when the timing requrirements are more stringent. For example, the timer service might be more than sufficient for an Embedlet to poll the value of a sensor on a periodic basis, but would not be a good choice for the generation of a pulse stream that had a very regular high- speed frequency. Does that help? Andrzej Jan Taramina Chaeron Corporation: Enterprise System Solutions http://www.chaeron.com |