c++ - Difference between `deadline_timer`and `waitable_timer` in `boost asio` -

c++ - Difference between `deadline_timer`and `waitable_timer` in `boost asio` -

to expire timer in 5 seconds, there practical difference between these two? 1 preferable(performance, resource, etc.) other case?

[option 1] deadline_timer:

boost::asio::deadline_timer timer(io_service); timer.expires_from_now(boost::posix_time::seconds(5));

[option 2] waitable_timer(system_timer or steady_timer):

boost::asio::system_timer timer(io_service); timer.expires_from_now(std::chrono::seconds(5));

ps: please concentrate on comparing deadline_timer vs. system_timer, rather system_timer vs. steady_timer.

the difference between clock types used.

as of boost 1.56, both basic_deadline_timer , basic_waitable_timer utilize detail::deadline_timer_service inside.

there's no difference in how performs waiting, difference in how performs time calculation.

in wait() method uses time_traits::now() check if needs wait more. system_timer it's std::chrono::system_clock::now(), , deadline_timer it's boost::posix_time::microsec_clock::universal_time() or boost::posix_time::second_clock::universal_time() depending on presence of high precision clock (see time_traits.hpp).

std::chrono::system_clock implementation provided compiler/standard library vendor, whereas boost::posix_time::*clock implemented boost using available scheme functions.

these implementations of course of study may have different performance and/or precision depending on platform , compiler.

c++ boost timer boost-asio