[Boost-users] [threads] Using boost::mutex raises access violation exception

From: v2cechura (v2cechura_at_[hidden])
Date: 2007-11-22 09:45:18

I just recently installed and built boost library (1.34.1) using
bcbboost. I wanted to try the boost::thread class. This simple 
code gives me "Access Violation" in Borland C++ Builder 2006 when
boost::mutex is 
used:

//--------------------------------------------------------------------------
-
#include <iostream>
#include <boost/thread.hpp>
//--------------------------------------------------------------------------
-
boost::xtime xt = {2};

boost::mutex console; // line A

void thr() // int n, boost::mutex & display
{
        for (int i = 0; i < 10; i++)
        {
                {
                        boost::mutex::scoped_lock l(console); // line B
                        std::cout << "thr" << 1 << ":" << i << std::endl;
                }
                boost::thread::sleep(xt);
        } // end for
}

int main(int argc, char* argv[])
{
        boost::thread_group tg;
        tg.create_thread(&thr);

        char c;
        std::cin >> c ;
        return 0;
}

If line A and line B are commented-out then the error is gone.

The project is a multithreaded console application, both boost.threads and
rtl are static-linked.

Caller stack is:
:7c812a5b kernel32.RaiseException + 0x52
:004129aa ___raiseDebuggerException + 0x1A
:00412a84 ; ___raiseDebuggerException
:7c9037bf ntdll.RtlConvertUlongToLargeInteger + 0x7a
:7c90378b ntdll.RtlConvertUlongToLargeInteger + 0x46
:7c90eafa ntdll.KiUserExceptionDispatcher + 0xe
:0041FA2B boost::mutex::do_unlock(this=NULL,  =:0012FDE8)
:0041E3A2 boost::detail::thread::lock_ops<boost::mutex>::unlock(m=NULL,
state=:0012FDE8)
:0041E12D boost::condition::do_wait<boost::mutex>(this=:0012FEA4,
mutex=NULL)
:0041DE2E
boost::condition::wait<boost::detail::thread::scoped_lock<boost::mutex>
>(this=:0012FEA4, lock=:0012FE5C)
:0041D42F
__UNNS__thread_01c827c2c2c9169a::thread_param::wait(this=:0012FE9C)
:0041D201 boost::thread::thread(this=:00000FCC, threadfunc=:00000FC8)
:00000001 
:0012fe01 

I put mutex.cpp in my directory and BCB2006 locates the error to
be here:

void mutex::do_unlock()
{
    if (m_critical_section) //------------- Access violation HERE 
        release_critical_section(m_mutex);
    else
        release_mutex(m_mutex);
}

The access violation is raised when thread::thread constructor
is called.

Looking at the caller stack I noticed that mutex parameter is 
NULL from some point and it results in this==NULL for the last 
call. Note that this mutex parameter is not the mutex "console" 
object I use in the program. It is a mutex that boost.threads 
library uses during thread initialization. On the other hand
there is some dependance on mutex "console" because when I 
comment it out the error is gone.

I maked console a pointer with appropriate changes to source and 
created it using new but it did not help.

Am I missing something?

Any help appreciated. Does anybody have experiences with 
boost::thread and mutex under BCB(2006,2007...)?

Vaclav