[Boost-bugs] [Boost C++ Libraries] #9385: Call current_exception in concurrent manner for the same exception object

Subject: [Boost-bugs] [Boost C++ Libraries] #9385: Call current_exception in concurrent manner for the same exception object
From: Boost C++ Libraries (noreply_at_[hidden])
Date: 2013-11-13 14:55:08

#9385: Call current_exception in concurrent manner for the same exception object
-------------------------------------------------+-------------------------
 Reporter:  cupper.jj@…                          |      Owner:
     Type:  Bugs                                 |  emildotchevski
Milestone:  To Be Determined                     |     Status:  new
  Version:  Boost 1.53.0                         |  Component:  exception
 Keywords:                                       |   Severity:  Problem
  boost::exception_detail::refcount_ptr          |
-------------------------------------------------+-------------------------
 In attached file you can find minimal test that crashes when uses boost
 implementation of exception_ptr. It happens when call current_exception in
 concurrent manner for the same exception object.

 Why does I expect that it should work? Because documentation does not say
 opposite (and it works in std implementation).

 In boost till
 1.42([http://www.boost.org/doc/libs/1_43_0/libs/exception/doc/exception_ptr.html])
 was said:
   Therefore, in general it is not safe to call rethrow_exception
 concurrently to throw the same exception object into multiple threads.

 And I have called it under mutex. But even in 1.42 was not said that call
 current_exception in concurrent manner (for the same exception object) not
 allowed.

 The problem in class boost::exception_detail::exception

 {{{#!c++
 class boost::exception_detail::exception
 {
 ...
   mutable
 exception_detail::refcount_ptr<exception_detail::error_info_container>
 data_;
 }}}

 when you call current_exception it's cloning current object of exception
 that create race condition.

 The documentation not enough clear about thread safety restrictions for
 current_exception and rethrow_excepoption.

 Here is back trace
 {{{
 #0  0x000000000225a110 in ?? ()
 #1  0x0000000000410455 in
 boost::exception_detail::refcount_ptr<boost::exception_detail::error_info_container>::add_ref()
 ()
 #2  0x000000000040dc0a in
 boost::exception_detail::refcount_ptr<boost::exception_detail::error_info_container>::refcount_ptr(boost::exception_detail::refcount_ptr<boost::exception_detail::error_info_container>
 const&) ()
 #3  0x000000000040c1ba in boost::exception::exception(boost::exception
 const&) ()
 #4  0x0000000000413033 in
 boost::exception_detail::current_exception_std_exception_wrapper<std::runtime_error>::current_exception_std_exception_wrapper(boost::exception_detail::current_exception_std_exception_wrapper<std::runtime_error>
 const&) ()
 #5  0x00000000004130bd in
 boost::exception_detail::clone_impl<boost::exception_detail::current_exception_std_exception_wrapper<std::runtime_error>
 >::clone_impl(boost::exception_detail::clone_impl<boost::exception_detail::current_exception_std_exception_wrapper<std::runtime_error>
 > const&) ()
 #6  0x0000000000420563 in
 boost::exception_detail::clone_impl<boost::exception_detail::current_exception_std_exception_wrapper<std::runtime_error>
 >::rethrow() const ()
 #7  0x000000000040cca8 in boost::rethrow_exception(boost::exception_ptr
 const&) ()
 #8  0x0000000000409825 in executer(boost::mutex&, boost::exception_ptr) ()
 #9  0x0000000000421ff2 in void
 boost::_bi::list2<boost::reference_wrapper<boost::mutex>,
 boost::_bi::value<boost::exception_ptr> >::operator()<void
 (*)(boost::mutex&, boost::exception_ptr),
 boost::_bi::list0>(boost::_bi::type<void>, void (*&)(boost::mutex&,
 boost::exception_ptr), boost::_bi::list0&, int) ()
 #10 0x00000000004211cd in boost::_bi::bind_t<void, void (*)(boost::mutex&,
 boost::exception_ptr),
 boost::_bi::list2<boost::reference_wrapper<boost::mutex>,
 boost::_bi::value<boost::exception_ptr> > >::operator()() ()
 #11 0x0000000000420122 in
 boost::detail::thread_data<boost::_bi::bind_t<void, void
 (*)(boost::mutex&, boost::exception_ptr),
 boost::_bi::list2<boost::reference_wrapper<boost::mutex>,
 boost::_bi::value<boost::exception_ptr> > > >::run() ()
 #12 0x00007fdff7194d29 in thread_proxy () from
 /home/roman-s/libraries/boost_1_53_0/stage/lib/libboost_thread.so.1.53.0
 #13 0x00007fdff6f71f8e in start_thread (arg=0x7fdff5178700) at
 pthread_create.c:311
 #14 0x00007fdff6782a0d in clone () at
 ../sysdeps/unix/sysv/linux/x86_64/clone.S:113
 }}}

 In my project where we use boost::exception on more difficult case,
 problem happens all time in refcount_ptr that try delete already deleted
 object. In this synthetical test problems arrives in a little bit another
 manner. But it's exactly reproduce our logic. Of course we can avoid this
 problem, but problem is.

 Thank you.

-- 
Ticket URL: <https://svn.boost.org/trac/boost/ticket/9385>
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