Re: [Mingw-users] runtime library: msvcrt not thread safe. How to use msvcr90?

[Alexander S. <ash...@gm...>]

On Thu, 20 Aug 2009 18:08:01 +0200
Frédéric Bron <fre...@m4...> wrote:

> Hi folks,
> 
> The simple program below crashes with segmentation fault when compiled
> in cygwin with option -mno-cygwin while it works perfectly when
> compiled with MSVC++ 2008.
> The difference is that the program compiled from cygwin is linked with
> msvcrt.dll while the one compiled from MSVC is linked with msvcr90.dll
> and msvcp90.dll.
> Do you know the difference between the libraries and why mingw uses
> a different one than MSVC?
> How can I use the same runtime library as MSVC with mingw but still
> get portable programs (I mean I can run them on any windows system)?
> 
> If it helps I am on Windows XP.
> 
> Frédéric
> 
> #include <iostream>
> #include <sstream>
> #include <boost/thread.hpp>
> 
> struct Task {
>        void operator()() {
>                for (size_t k=0 ; k<10000 ; ++k) {
>                        double x ;
>                        std::istringstream is("10.") ;
>                        is >> x ;
>                }
>        }
> } ;
> 
> int main() {
>        boost::thread_group g_thread ;
>        for (size_t k=0 ; k<10 ; ++k) g_thread.create_thread(Task()) ;
>        g_thread.join_all() ;
>        return 0 ;
> }


Are you sure the CRT library is the culprit?
std::istringstream is part of libstdc++, which is part of gcc.
So, I would assume that it's libstdc++ that's non-reentrant here.
Maybe the recently discussed broken __thread in 4.4.0 has
something to do with this.
Which mingw version are you using?


Alexander