Re: [Boost-users] seg fault on windows with Boost threads, istringstream, mingw

Subject: Re: [Boost-users] seg fault on windows with Boost threads, istringstream, mingw
From: Kenny Riddile (kfriddile_at_[hidden])
Date: 2009-01-30 05:25:32

Tod Courtney wrote:
> I believe the problem is related to this code, which uses a
> istringstream to convert a string to a basic type (say a double):
> 
> template <typename T>
> bool FromString(T &t,const std::string &s,
>         std::ios_base &(*f)(std::ios_base &)=std::dec) {
>    std::istringstream iss(s);
>    return !(iss >> f >> t).fail();
> }

Somewhat off-topic, but couldn't you maybe use boost::lexical_cast to do 
this?

> 1) Is there a multi-thread bug in the MinGW implementation istringstream?

If there is, I wouldn't call it a bug.  The standard library makes no 
guarantees about thread safety.  For all you know a std::string 
implementation could internally reference-count its buffers in a 
non-thread-safe way.

 > // wait until all threads to end
 >  for(int n=0;n<numThreads;n++) {
 >    worker[n]->join();
 >    delete worker[n];
 >    delete vec[n];
 >  }

Does moving the two delete calls outside of this loop so that no deletes 
happen until all threads have finished fix the problem?  If so, you 
might consider using boost::ptr_vector to eliminate the explicit deletes 
  and simplify some of the allocation code.