Boost::调用join时发生线程访问冲突

我在尝试创建多线程服务器时遇到一些问题。一切都很好，直到我需要从服务器上删除一个客户端。

服务器在自己的线程中运行，然后每个客户端也有自己的线程。

我对所有线程使用boost:：thread。当我需要停止客户端时，我会呼叫

void StopClient()
{
    assert(mThread);
    mStopMutex.lock();
    mStopRequested = true;
    mStopMutex.unlock();
    shutdown(mSocket,2);
    mThread->join();
}

向行添加断点

shutdown(mSocket,2);

我可以看到mThread不存在！这是否意味着线程已经退出？是否总是需要调用join((来获得boost:：线程？

如果我允许代码运行，我会得到一个访问冲突错误。

更新

服务器线程

void StartServer() 
{
    assert(!mListenThread);
    mListenThread = boost::shared_ptr<boost::thread>(new boost::thread(boost::bind(&ServerThread::Listen, this)));
    mUpdateThread = boost::shared_ptr<boost::thread>(new boost::thread(boost::bind(&ServerThread::Update, this)));
}
void StopServer()
{
    assert(mListenThread);
    mStopRequested = true;
            mMutex.lock();
            for(int i = 0; i < mClients.size(); i++ )
                mClients[i]->StopClient();
            mMutex.unlock();
    mListenThread->join();
}
void Listen()
{
    while (!mStopRequested)
    {
        std::cout << "Waiting for connection" << std::endl;         
        if(mClientSocket = accept( mServerSocket, (sockaddr*) &mServerAddr, &addrlen ) )
        {
            mMutex.lock();
            if( mClients.size() > 0 )
            {
                for( int i = 0; i < mClients.size(); i++ )
                {
                    if( mClients[i]->getClientSocket() != mClientSocket )
                    {
                        ClientThread newClient;
                        newClient.Initialise(mClientSocket);
                        mClients.push_back(&newClient);
                        mClients[mClients.size()-1]->StartClient();
                        break;
                    }
                }
            }
            else
            {
                ClientThread newClient;
                newClient.Initialise(mClientSocket);
                mClients.push_back(&newClient);
                mClients[mClients.size()-1]->StartClient();
            }
            mMutex.unlock();
        }
    }
}          
void Update()
{
    while (!mStopRequested)
    {
        mMutex.lock();
        std::cout << "::::Server is updating!::::" << mClients.size() << std::endl;
        for( int i = 0; i< mClients.size(); i++ )
        {
            if( !mClients[i]->IsActive() )
            {
                mClients[i]->StopClient();
                mClients.erase( mClients.begin() + i );
            }
        }
        mMutex.unlock();
    }
}

客户端线程

void StartClient()
{
    assert(!mThread);
    mThread = boost::shared_ptr<boost::thread>(new boost::thread(boost::bind(&ClientThread::Update, this)));
}
void Update()
{
    bool stopRequested;
    do
    {
        mStopMutex.lock();
        stopRequested = mStopRequested;
        mStopMutex.unlock();
        std::cout << "lol" << std::endl;
        if( mTimeOut < 1000 )
        {
            mTimeOut++;
        }
        else
        {
            mActive = false;
        }
        boost::this_thread::interruption_point();
    }
    while( !stopRequested);
}

            ClientThread newClient;
            newClient.Initialise(mClientSocket);
            mClients.push_back(&newClient);