Re: [Boost-users] [Boost-user]multithreaded app hangs in boost libraries

Farberov, Inga wrote:

Hello,

I have written a static library that uses boost program_options, threads, date-time and serialization libraries. There is also an extensive use of shared_ptr.

I am working on a multithreaded application, so when I link my library into the executable, I use multithreaded versions of the boost libraries. When I compile my library and application that links to it, I use -pthread flag in attempt to make it multi-threaded.

Everything compiles and links without a problem, however when I try to run the application, it hangs. I have tried to bedug it and when I suspend a hanging thread it gives me following stack trace:

...

9 pthread_mutex_lock() 0x0042097e

8 scoped_lock() /usr/include/boost/detail/lwm_pthreads.hpp:72 0x080598eb

7 boost::detail::sp_counted_base::add_ref_copy() /usr/include/boost/detail/shared_count.hpp:122 0x0805b679

6 shared_count() /usr/lib/boost/include/boost-1_34/boost/detail/shared_count.hpp:216 0x0805b65b

This stack trace makes no sense to me. I understand the shared_count:216 portion; it's the line: if( pi_ != 0 ) pi_->add_ref_copy(); But the next level, add_ref_copy is shown to be at shared_count.hpp:122, and there's no add_ref_copy there. shared_count:122 is the line pi_ = new sp_counted_impl_pd(p, d); in the no-exception branch of shared_count( p, d ). Next down the stack we have scoped_lock at lwm_pthreads.hpp:72; this is even more baffling. add_ref_copy doesn't call into lwm_pthreads; it would typically call into sp_counted_base_gcc_*.hpp if you CPU is x86, PPC or IA64, or sp_counted_base_pt if it isn't. Are you sure that you aren't using 1.34 headers and older libraries? Have you used -DBOOST_SP_USE_QUICK_ALLOCATOR by any chance? Can you try placing a static boost::shared_ptr<int> p( new int ); variable before your Settings variable? Can you try a debug version of boost::program_options with inlining off, in a hope that this will produce a more reliable stack trace?