Re: Inserting into a map corrupting the map data

From:

"John H." <oldman_fromthec@yahoo.com>

Newsgroups:

microsoft.public.vc.stl

Date:

Wed, 7 Apr 2010 16:31:55 -0700 (PDT)

Message-ID:

<08f97a65-baa9-4ad3-b3d1-f8c04a58a718@q15g2000yqj.googlegroups.com>

Aditya wrote:

typedef map<long, long> CIndexToDataMap;
CIndexToDataMap m_IndexToDataMap;

HRESULT Thread1Method()
{
    {
    AutoLock autoLock(m_CritSec);
       Trace(_T("Before inserting Map size is = %d...\n"),
m_IndexToDataMap.size()); // size 10
    CIndexToDataMap ::iterator itr = m_IndexToDataMap.begin();
    while (itr != m_IndexToDataMap.end())
    {
      Trace(_T("Index%d corresponds to data %d."), itr->first, itr-

second); // can see all the 10 data

  itr++;
    }
   }

   {
    AutoLock autoLock(m_CritSec);
    m_IndexToDataMap.insert(pair<long, long>(nIndex, ldata));
    Trace(_T(" After inserting Map size is = %d...\n"),
m_IndexToDataMap.size()); //size is 11

        for(CIndexToDataMap ::iterator itr1 =
m_IndexToDataMap.begin(); itr1 != m_IndexToDataMap.end(); ++itr1)
    {
     Trace(_T("Index%d corresponds to data %d."), itr1->first, itr1-

second); //PROBLEM HERE, can see only 2 records

}
}

HRESULT Thread2Method(nIndex)
{
   AutoLock autoLock(m_CritSec);
   if (m_IndexToDataMap.find(nIndex) != m_IndexToDataMap.end())
   {
    nScanConfigIndex = m_IndexToDataMap[nIndex];
    return TRUE;
   }
}

I couldn't eyeball the problem, but the code you posted is not
compilable so I couldn't see what was wrong by running it either. Do
you think you could try to simplify the project and post a minimum set
of code that demonstrates the problem?