Ernest Galbrun wrote:

Dear Boost community,

I have a rather simple question (some would say dumb) : I have been using the deadline_timer in asio library for a couple of hours, but I don't get why it is associated with an io_service (in fact, I don't get why this is in this library rather than in the date_time or timer library).

I know it may seem trivial, but it is not to me, and I am worried I am missing something.

regards,

Ernest Galbrun.

Ernest - Asio provides a proactor implementation that is useful for many asynchronous tasks. It happens to provide a timer service which you are using with deadline_timer. So, why is deadline_timer associated with io_service? Because the io_service is part of the proactor. Why not in a different library? There maybe other timer facilities in other libraries; however, it is very common to need timers in an asynchronous design. Having a timer service makes good sense. You are approaching the problem from a "I need a timer" point-of-view. Why the deadline_timer is part of Asio is answered from the "what is part of an async-IO library" point-of-view. If you are not familiar with the proactor and how it works, this link may be useful: http://www.objectmodelingdesigns.com/boostcon10/asio_presentation_with_story... hth - michael -- ---------------------------------- Michael Caisse Object Modeling Designs www.objectmodelingdesigns.com