Question

I use python version of libtorrent. When I run a torrent session for a longer time with many files, it crashes with an error:

terminate called after throwing an instance of 'boost::lock_error'
  what():  boost::lock_error

so, I thought I will wrap the torrent related function into a separate thread and when it crashes, it will kill just the thread (instead of the entire app):

from threading import Thread

class TWrapper (Thread) :
    #  ...
    def run(self):
        try:
            run_torrent_stuff()
        except:
            # print message
            pass


t = TWrapper()
t.run()
t.join()
# check if all OK with t, if not - restart again

I thought that if the library crashes, the thread will die and I will join it in the main loop. But, when the libtorrent crashes, all the application dies 🙁

Why the error escalates outside the thread?

(libtorrent is an example (real life), the question is general)

Answer 1

Usually if thread crashes, it leads to process crash, if you want to avoid it run libtorrent in a separate process.