c++ - C++ Non-Blocking ASIO Run

Question

I have created a series of functions that talk to Libcurl Multi and download files asynchronously via ASIO and Boost.

Obviously though when I call io_service.run it blocks my main thread when it is run. I have tried to make it non blocking but my app crashes.

I was wondering what is the simplest and best approach to running this in the background, in a non-blocking manner and have it call a call-back function when it is done (Like how you can do it in javascript).

So I could just go:

Runthisinthebackground( thingtodo, callback); 

It would run the thingtodo and return the result to the callback. One thing though this must use Libraries such as boost that can run on devices with out C++ 11 as its for a mobile app running on Android and iOS

Answer 1

Run io_service in another thread and post to it your functions:

asio::io_service io_service;
// give it some work, to prevent premature exit
shared_ptr<asio::io_service::work> work(new asio::io_service::work(io_service));
boost::thread t(&asio::io_service::run, &io_service);
t.detach();
//...
io_service.post(yourFunctor); // yourFunctor will be executed in the separate thread