[asio] Handling of unix signals

[dgoncharov@…]

This proposal suggests adding to asio the ability to invoke a handler whenever a unix signal arrives.

Motivation:

1. The extension lets the user have a unix signal handler of an arbitrary signature.

2. The extension also removes the "async-signal safe calls" restriction from a handler of a unix signal.

The extension is supposed to be used like this:

void on_signal(boost::system::error_code const& error) {

if (!error)

cout << "sigint received" << endl;

}

int main(int argc, char const* argv[])

{

boost::asio::io_service ios; boost::asio::posix::signal_handler<SIGINT> sigint(ios); while (true) {

ios.reset(); sigint.async_wait(boost::bind(on_signal, _1)); ios.poll();

}

}

The original proposal on the mail list can be found here. ​http://lists.boost.org/Archives/boost/2009/03/149890.php

Please find the implementation and examples in the attachments.

[dgoncharov@…]

an example

[dgoncharov@…]

implementation

[dgoncharov@…]

implementation

[dgoncharov@…]

an example

[samjmill@…]

adding myself, this is exactly what I've been looking for. Any chance this feature can make it into the next version of asio?

[kyle.tarplee@…]

I would like this as well.

[anonymous]

There was also interest aside from the mail list. So, i made a small library out of this proposal. The library can be found here ​http://github.com/dgoncharov/libunixsignal/. The library uses autotools. So, basically all you need to do is to type ./configure; make install.

[anonymous]

Forgot to subscribe the previous comment. dgoncharov at unison.com

[boris@…]

Signal handler based on Boost.Asio design guidelines

[anonymous]

The implementation proposed in the last comment is incorrect. It uses async-signal-unsafe syscalls like locking a mutex inside a signal handler.

[bschaeling]

Updated signal handler (based on Boost.Asio design patterns)

[bschaeling]

I've updated the signal handler's implementation. Can you (who you are anonymous :-) please check the new version? It uses a pipe now (there is only write() called in the signal handler function). The tests are still all passed.

[chris_kohlhoff]

As of [72428], the release branch contains the new signal_set class.