Hello all I am getting segmentation faults when we use our program in multithreaded mode on linux (RedHat 9). The same code runs flawlessly on windows. The crash always happens in boost::regex_replace. I had read the following posts on this topic: http://lists.boost.org/MailArchives/boost/msg59110.php and http://lists.boost.org/boost-users/2005/01/9712.php Accordingly, I've initialised all the regexes before the main working threads starts. I also came across the gcc string threading issue at http://gcc.gnu.org/bugzilla/show_bug.cgi?id=21334 and switched to STLport but to no avail. If anything, the crash happens much more quickly. Stack trace is as follows: Program received signal SIGSEGV, Segmentation fault. [Switching to Thread 1129827392 (LWP 3124)] 0x4013f843 in boost::re_detail::basic_regex_formatter<boost::re_detail::string_out_iterator<stlp_std::basic_string<wchar_t, stlp_std::char_traits<wchar_t>, stlp_std::allocator<wchar_t> > >, boost::match_results<wchar_t const*, stlp_std::allocator<boost::sub_match<wchar_t const*> > >, boost::regex_traits_wrapper<boost::regex_traits<wchar_t, boost::cpp_regex_traits<wchar_t> > > >::format_all() ( this=0x4357bcfc) at regex_format.hpp:133 133regex_format.hpp: No such file or directory. in regex_format.hpp (gdb) bt Thread 3 (Thread 1129827392 (LWP 3124)): #0 0x4013f843 in boost::re_detail::basic_regex_formatter<boost::re_detail::string_out_iterator<stlp_std::basic_string<wchar_t, stlp_std::char_traits<wchar_t>, stlp_std::allocator<wchar_t> > >, boost::match_results<wchar_t const*, stlp_std::allocator<boost::sub_match<wchar_t const*> > >, boost::regex_traits_wrapper<boost::regex_traits<wchar_t, boost::cpp_regex_traits<wchar_t> > > >::format_all() (this=0x4357bcfc) at regex_format.hpp:133 #1 0x4013f72c in boost::re_detail::basic_regex_formatter<boost::re_detail::string_out_iterator<stlp_std::basic_string<wchar_t, stlp_std::char_traits<wchar_t>, stlp_std::allocator<wchar_t> > >, boost::match_results<wchar_t const*, stlp_std::allocator<boost::sub_match<wchar_t const*> > >, boost::regex_traits_wrapper<boost::regex_traits<wchar_t, boost::cpp_regex_traits<wchar_t> > > >::format(wchar_t const*, wchar_t const*, boost::regex_constants::_match_flags) ( this=0x4357bcfc, p1=0x4357bdac, p2=0x4357bdc4, f=50331648) at regex_format.hpp:123 #2 0x4013f5bd in boost::re_detail::string_out_iterator<stlp_std::basic_string<wchar_t, stlp_std::char_traits<wchar_t>, stlp_std::allocator<wchar_t> > > boost::re_detail::regex_format_imp<boost::re_detail::string_out_iterator<stlp_std::basic_string<wchar_t, stlp_std::char_traits<wchar_t>, stlp_std::allocator<wchar_t> > >, wchar_t const*, stlp_std::allocator<boost::sub_match<wchar_t const*> >, wchar_t, boost::regex_traits_wrapper<boost::regex_traits<wchar_t, boost::cpp_regex_traits<wchar_t> > >
(boost::regex_traits_wrapper<boost::regex_traits<wchar_t, bo ost::cpp_regex_traits<wchar_t> > >, boost::match_results<wchar_t const*, stlp_std::allocator<boost::sub_match<wchar_t const*> > > const&, wchar_t const*, wchar_t, boost::regex_constants::_match_flags, boost::regex_traits_wrapper<boost::regex_traits<wchar_t, boost::cpp_regex_traits<wchar_t> > > const&) (out=
{<iterator<stlp_std::output_iterator_tag,wchar_t,int,wchar_t*,wchar_t&>> = {<No data fields>}, out = 0x4357becc}, m=@0x80c3d70, p1=0x4357bdac, p2=0x4357bdc4, flags=50331648, t=@0x8077d48) at regex_format.hpp:569 #3 0x4013f28c in format<boost::re_detail::string_out_iterator<stlp_std::basic_string<wchar_t, stlp_std::char_traits<wchar_t>, stlp_std::allocator<wchar_t> > >, boost::basic_regex<wchar_t, boost::regex_traits<wchar_t, boost::cpp_regex_traits<wchar_t> > > > (this=0x80c3d70, out= {<iterator<stlp_std::output_iterator_tag,wchar_t,int,wchar_t*,wchar_t&>> = {<No data fields>}, out = 0x4357becc}, fmt=@0x4357bdac, flags=50331648, re=@0x810eefc) at match_results.hpp:170 #4 0x4013ed6b in boost::re_detail::string_out_iterator<stlp_std::basic_string<wchar_t, stlp_std::char_traits<wchar_t>, stlp_std::allocator<wchar_t> > > boost::regex_replace<boost::re_detail::string_out_iterator<stlp_std::basic_string<wchar_t, stlp_std::char_traits<wchar_t>, stlp_std::allocator<wchar_t> > >, wchar_t const*, boost::regex_traits<wchar_t, boost::cpp_regex_traits<wchar_t> >, wchar_t>(boost::re_detail::string_out_iterator<stlp_std::basic_string<wchar_t, stlp_std::char_traits<wchar_t>, stlp_std::allocator<wchar_t> > >, wchar_t const*, boost::re_detail::string_out_iterator<stlp_std::basic_string<wchar_t, stlp_std::char_traits<wchar_t>, stlp_std::allocator<wchar_t> > >, boost::basic_regex<wchar_t, boos t::regex_traits<wchar_t, boost::cpp_regex_traits<wchar_t> > > const&, boost::re_detail::string_out_iterator<stlp_std::basic_string<wchar_t, stlp_std::char_traits<wchar_t>, stlp_std::allocator<wchar_t> > > const*, boost::regex_constants::_match_flags) (out= {<iterator<stlp_std::output_iterator_tag,wchar_t,int,wchar_t*,wchar_t&>> = {<No data fields>}, out = 0x4357becc}, first=0x4357bfdc, last=0x4357bff8, e=@0x810eefc, fmt=0x4357bf3c, flags=50331648) at regex_replace.hpp:53 #5 0x4013e123 in stlp_std::basic_string<wchar_t, stlp_std::char_traits<wchar_t>, stlp_std::allocator<wchar_t> > boost::regex_replace<boost::regex_traits<wchar_t, boost::cpp_regex_traits<wchar_t> >, wchar_t>(stlp_std::basic_string<wchar_t, stlp_std::char_traits<wchar_t>, stlp_std::allocator<wchar_t> > const&, boost::basic_regex<wchar_t, boost::regex_traits<wchar_t, boost::cpp_regex_traits<wchar_t> > > const&, stlp_std::basic_string<wchar_t, stlp_std::char_traits<wchar_t>, stlp_std::allocator<wchar_t> > const, boost::regex_constants::_match_flags) ( s=@0x4357bfdc, e=@0x810eefc, fmt=@0x4357bf3c, flags=50331648) at regex_replace.hpp:96 #6 0x4013d9c5 in RegExRuleSet::ApplyRules(stlp_std::basic_string<wchar_t, stlp_std::char_traits<wchar_t>, stlp_std::allocator<wchar_t> >&) (this=0x807d93c, zrTok=@0x4357c12c) at common/utils/RuleApplier.cpp:192 #7 0x4014d42a in Transform1::PhonetizeAndSyllabify(stlp_std::vector<Item, stlp_std::allocator<Item> >&) (this=0x807d8e8, zrItems=@0x4188d448) at textProcessor/Transforms/Transform1/Transform1.cpp:620 #8 0x4014c0f9 in Transform1::Process(stlp_std::vector<Item, stlp_std::allocator<Item
&) (this=0x807d8e8, zrItems=@0x4188d448) at textProcessor/Transforms/Transform1/Transform1.cpp:326 #9 0x4012f327 in Fragment::ProcessTransforms(int) (this=0x4188d448, zLangIndex=0) at common/shared/Fragment.cpp:187 #10 0x40119ef8 in Engine::ProcessFragment() (this=0x4357c50c) at main/Engine.cpp:64 #11 0x401110b4 in Input2Stage1(wchar_t const*, Engine&, int) ( zpText=0x80b9cb0, zrEngineObj=@0x4357c50c, zLangIndx=0) at main/InterfaceFunctions.cpp:137 #12 0x401039da in GetOutput (zpText=0x80b9cb0, zSamplingRate=16000, zBitRate=16, zTimeModFact=1, zPitchModFact=0, zpOutFileName=0x4357c60c "./buffer/Thread_1_Line_3.wav", zLangIndx=0, zOutput=WAVEFILE, zppWaveBuffer=0x0) at main/Interface.cpp:185 #13 0x08056ea4 in GetOutputer(void*) (zpThreadPara=0xbfffe5b0) at testing/MultiThreadedApp.cpp:194 #14 0x404da2b6 in start_thread () from /lib/tls/libpthread.so.0
The code fragment is as follows vector <Rule>::iterator yIterInRule = this->inclusiveRuleSet.begin(); for (; yIterInRule != inclusiveRuleSet.end(); yIterInRule++) { const boost::wregex &ySearchExp = yIterInRule->getSearchExpr(); yReplaceStr.assign(yIterInRule->getReplaceExpr()); if (yIterInRule->getContinousStatus() == false) { yInputStr = regex_replace(yInputStr,ySearchExp, yReplaceStr, boost::format_all | match_default | format_sed); } else { do { yInputStr = boost::regex_replace(yInputStr,ySearchExp, yReplaceStr, boost::format_all | match_default | format_sed); ystart = yInputStr.begin(); yend = yInputStr.end(); } while (boost::regex_search(ystart, yend,ySearchExp)); } // End Else }// end of inclusiveRuleSet for loop It crashes in any of the two regex_replace calls. OS is Red Hat Linux 9 The compiler is gcc-3.2.2 STLport is STLport-5.0.2 boost is boost_1_33_1 Crash happens only on multiprocessor machines. It would overcome a great roadblock if someone helps Thanks in advance Yours Sincerely Ashish Varman
Ashish Varman wrote:
Hello all
I am getting segmentation faults when we use our program in multithreaded mode on linux (RedHat 9). The same code runs flawlessly on windows. The crash always happens in boost::regex_replace. I had read the following posts on this topic: http://lists.boost.org/MailArchives/boost/msg59110.php and http://lists.boost.org/boost-users/2005/01/9712.php Accordingly, I've initialised all the regexes before the main working threads starts.
Stack trace is as follows: Program received signal SIGSEGV, Segmentation fault. [Switching to Thread 1129827392 (LWP 3124)] 0x4013f843 in
I notice that the line mentioned in the stack trace is: switch(*m_position) So segmentation fault occurs on iterator dereference. Is there any way that your string being searched can be changed by another thread? After that: are you linking against the thread safe regex lib (the one with -mt in the name)? If not the next sanity check to do is to build and run the test program libs/regex/test/static_mutex/static_mutex_test.cpp - you will need to link this to both Boost.Regex and Boost.Thread. It'll do a basic check to verify that Boost.Regex's static mutex code is working correctly (it uses PTHREAD_MUTEX_INITIALIZER). If this fails then there is an issue with pthreads on the platform std lib combination you're using: try updating glibc if you can. After that try defining BOOST_REGEX_RECURSIVE in boost/regex/user.hpp: it'll then use the same code that it does on Win32, however linux is rather less tolerant of potential stack-overflows than Win32, which is why this isn't the default. You'll need to rebuild everything, including Boost.Regex to try this. HTH, John.
participants (2)
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Ashish Varman -
John Maddock