Boost C++ Libraries: Ticket #10093: Exceptions "teleport" between coroutines when switching inside catch

component changed

olli — Thu, 05 Jun 2014 06:21:13 GMT

component coroutine → context

boost.context provides the 'jump' facility

snaury@… — Thu, 05 Jun 2014 19:10:57 GMT

In my opinion boost.context is too low level for this, for example boost.context doesn't know anything about exceptions (and boost.coroutine does), besides calling C++ ABIs from assembler would be too tedious, and there's just nothing platform-dependant about it (more compiler or libc++ dependant). At the same time boost.coroutine has its own abstraction, coroutine_context, where coroutine_context::jump would be easy to modify: declare and call __cxx_get_globals() (similar to the way boost.log already does) and save/restore the exception information.

olli — Thu, 05 Jun 2014 20:44:06 GMT

Replying to snaury@…:

for example boost.context doesn't know anything about exceptions

boost.context handles Windows' structured exception handling

olli — Mon, 09 Jun 2014 08:51:48 GMT

32bit MSVC works
64bit MSVC crashes the app - no info regarding to this issue found in the INet
compiler using C++ Itanium ABI are problematic because cxaget_globals() does call malloc() store/restore of __cxa_eh_globals::caughtExceptions and __cxa_eh_globals::uncaughtExceptions per context we might end up with memory leaks (== closing a context without cleaning up its list of the active exceptions).

=> maybe the best solution would be a hint in the docu. not to call context inside a catch-block

status changed; resolution set

olli — Sat, 23 Aug 2014 12:29:56 GMT

status new → closed
resolution → wontfix

It is not easy to solve because the different compilers handle it in a different way. even worse for some compilers (for instance MSVC) it is not know where currently catched exceptions are stored.

I've added a note in the doc not to re-throw exceptions from a catch-clause inside a coroutine/context.