C++: How to implement a timeout for an arbitrary function call


I need to call a library function that sometimes won't terminate within a given time, unfortunately. Is there a way to call the function but abort it if it doesn't terminate within n seconds?

I cannot modify the function, so I cannot put the abort condition into it directly. I have to add a timeout to the function externally.

Is it maybe a possible solution to start it as a (boost) thread, which I can then terminate after a certain time? Would something like that work? I actually believe the function is not thread-safe, but that wouldn't matter if I run it as the only single thread, right? Are there other (better) solutions?

Best Solution

You could spawn a boost::thread to call the API:

boost::thread api_caller(::api_function, arg1, arg2);
if (api_caller.timed_join(boost::posix_time::milliseconds(500)))
    // API call returned within 500ms
    // API call timed out

Boost doesn't allow you to kill the worker thread, though. In this example, it's just orphaned.

You'll have to be careful about what that API call does, because it may never release resources it's acquired.