Re: [Boost-users] [spirit] Segmentation fault when parsing grammar with threads

From: Jeff Flinn (TriumphSprint2000_at_[hidden])
Date: 2008-03-06 18:30:38

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Jeff Flinn

Andreas Bruckmeier wrote:
> Hi out there,
> 
> after searching for the cause of segmentation faults in my program 
> i figured out that it happens while parsing my grammar with spirit.
> But this happens only if i run multiple threads, 
> with only one thread all works as expected.
> 
> I used the current boost trunk, gcc 4.1.2 and option D_REENTRANT
> 
> Does anybody have a clue what happens inside parse(...) 
> that could cause this segfault?
> 
> Best regards
> Andi
> 
> calling code: ('buf' is a zero-terminated string)
> --------------------------------------------------------
> HttpRequestGrammar parser;
> parse_info<const char*> parserInfo = parse(buf, parser);
> 
> 
> my grammar: (cutted some rules to limit length ;-))
> --------------------------------------------------------
> #ifndef BASIC_HTTP_GRAMMAR_H_
> #define BASIC_HTTP_GRAMMAR_H_
> 
> #include <boost/spirit/core.hpp>
> #include <boost/spirit/actor/assign_actor.hpp>
> #include <boost/spirit/actor/insert_at_actor.hpp>
> 
> using namespace boost::spirit;
> 
> struct HttpRequestGrammar : public grammar<HttpRequestGrammar> {
> 
>   template <typename ScannerT> struct definition {
> 
>     definition(HttpRequestGrammar const& self) {
>       first = (
> 
>         request                = *( SP | CRLF ) >> requestLine >> CRLF 
>                                  >> *(( generalHeader | requestHeader |
> entityHeader ) >> CRLF) >> CRLF,
> 
>         requestLine            = method[insert_at_a(self.headerMap,
> "method")] >> SP 
>                                  >> requestUri[insert_at_a(self.headerMap,
> "url")] 
>                                  >> SP >>
> httpVersion[insert_at_a(self.headerMap, "version")],
> 
>         method                 = str_p("GET") | "HEAD",
> ...
> ..
>         token                  = +graph_p,
>         SP                     = str_p(" "),
>         CRLF                   = str_p("\r\n")
>       );
>     }
> 
>     subrule<0> request;
>     subrule<1> requestLine;
>     subrule<2> generalHeader;
> ...
> ..
>     subrule<1000> SP;
>     subrule<1001> CRLF;
> 
>     rule<ScannerT> first;
>     rule<ScannerT> const&
> 
>     start() const {
>       return first;
>     }
> 
>   };
> 
>   mutable std::map<std::string, std::string> headerMap; };
> 
> #endif /*BASIC_HTTP_GRAMMAR_H_*/