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I've written an io_service+signal_set signal handling implementation in a thread of my application that triggers an orderly shutdown when (among other things) the user presses Ctrl+C.

I first hear about asio signals, but I believe purpose of these signal facility in asio is only to help you to implement *waiting* for signals, like SIGCHLD, or SIGUSR{12}, whateverer you may choose for your IPC communication. You should not misuse asio for general signal handling. Normally signals are instantaneous things to be delivered right now right here without any regard in which state the target is.

I personally agree with Benjamin and think that the main goal of asio::signal_set is to provide the Asio way to handle signals. Look at the Asio examples (http://www.boost.org/doc/libs/1_55_0/doc/html/boost_asio/examples/cpp03_exa mples.html) - the "HTTP Servers" series. They use asio::signal_set for the same goal/reason as Benjamin does. Regards, Marat Abrarov.