Howdy, I've come across an odd segfault that originates in some of the boost code. (By originate, meaning thats where the stack trace points, I'm not sure if its me or boost thats wrong) Anyway, the weird part is that its only on my 64 bit machine. I took a look at where its segfaulting in boost::detail::atomic_exchange_and_add(). Its scary inline assembly stuff. Well, mostly I just don't know assembly so I haven't the slightest idea if its right or wrong. And obviously, its a platform specific header and what not so I imagine its limited to this area. I have had other weird segfaults that come and go from the atomic_* set of methods. I can't pin down exactly whats causing it. They mostly seem to be coming from storing shared_ptr's in STL containers. I've never had any problems with it before so I'm assuming its just a relatively untested section of code. And if its relevant, I also tried downloading CVS and running the shared_ptr_test. It ran without segfaulting just fine. Some relevant info: Segfaults on: 2.6.15-25-amd64-generic #1 SMP PREEMPT Wed Jun 14 11:28:03 UTC 2006 x86_64 GNU/Linux g++ (GCC) 4.0.3 (Ubuntu 4.0.3-1ubuntu5) boost/version.hpp #define BOOST_VERSION 103301 Does NOT segfault on: 2.6.15-1.1831_FC4smp #1 SMP Tue Feb 7 13:48:31 EST 2006 i686 i686 i386 GNU/Linux g++ (GCC) 4.0.2 20051125 (Red Hat 4.0.2-8) boost/version.hpp : #define BOOST_VERSION 103200 Stack trace: Program received signal SIGSEGV, Segmentation fault. [Switching to Thread 46912529528592 (LWP 27560)] 0x000000000040a2f8 in boost::detail::atomic_exchange_and_add (pw=0x98, dv=-1) at sp_counted_base_gcc_x86.hpp:50 50 ); (gdb) bt #0 0x000000000040a2f8 in boost::detail::atomic_exchange_and_add (pw=0x98, dv=-1) at sp_counted_base_gcc_x86.hpp:50 #1 0x000000000040a46c in boost::detail::sp_counted_base::release (this=0x90) at sp_counted_base_gcc_x86.hpp:143 #2 0x000000000040a4d0 in ~shared_count (this=0x2514218) at shared_count.hpp:159 #3 0x00002aaaaccb849b in ~shared_ptr (this=0x2514210) at shared_ptr.hpp:106 #4 0x00002aaaaccb88e1 in __gnu_cxx::new_allocator<boost::shared_ptr<min_heap> >::destroy (this=0x7fffffc2b410, __p=0x2514210) at new_allocator.h:107 #5 0x00002aaaaccb9f66 in std::vector<boost::shared_ptr<min_heap>, std::allocator<boost::shared_ptr<min_heap> > >::erase ( this=0x7fffffc2b410, __position={_M_current = 0x2514220}) at vector.tcc:115 #6 0x00002aaaaccb7add in label_map::CloseToAlive (this=0x7fffffc2b3e0, p=@0x7fffffc2b1a0) at build/Modules/Marching/label_map.cc:273 #7 0x00002aaaaccb326f in fast_march::march (this=0x7fffffc2b3c0, mask=@0x527d30, gradient=@0x527d10, labeled=@0x527d40) at build/Modules/Marching/fast_march.cc:76 #8 0x00002aaaaccbec64 in marching::run (this=0x527c50, cli=@0x7fffffc2b5e0, options=@0x7fffffc2b5d0, args=@0x7fffffc2b5c0) at build/Modules/Marching/marching.cc:110 #9 0x00000000004074bd in process (args=@0x7fffffc2c460) at build/DDS/dds.cc:259 #10 0x0000000000408ffd in main (argc=2, argv=0x7fffffc2c5a8) at build/DDS/dds.cc:531 Paul Davis