Question

我有以下代码用于从队列中推送和挂起。调用者代码具有多个MsgQ对象。 Push和Pend函数可能正在等待_notFull->wait()和_notEmpty->wait()条件等待。这些等待受_mut互斥锁保护。 notFull和notEmpty等待对empty和full变量进行操作。

当调用析构函数时，_deleteQueue在内部被调用，我希望从中向等待的线程发出信号以进行清理并停止等待信号到来。完成后，我删除了我的对象。但是，在_deleteQueue函数中，当我尝试_mut->acquire()时，我无法获取互斥锁。即使我忽略了获取，我也无法broadcast这些等待的线程。我哪里错了？

谢谢，维克拉姆。

    MsgQ::~MsgQ()
{
    _deleteQueue();

    delete _mut;_mut=NULL;
    delete  _notFull;_notFull=NULL;
    delete _notEmpty;_notEmpty=NULL;
    delete _PostMutex; _PostMutex = NULL;
    delete _PendMutex; _PendMutex = NULL;
    delete _PostInProgressMutex; _PostInProgressMutex = NULL;
    delete _PendInProgressMutex; _PendInProgressMutex = NULL;
    delete _DisconnectMutex; _DisconnectMutex = NULL;
    free( _ptrQueue ); _ptrQueue = NULL;
}

int MsgQ::Post(Message* msg)
{
    _PostMutex->acquire();
    _postInProgress++;
    _PostMutex->release();

    if (msg)
    msg->print();

    _mut->acquire();
    while (full) 
    {
    _notFull->wait();
    }

    if (!_disconnectInProgress)
    _queuePush(msg);
    _mut->release();

    _PostMutex->acquire();
    _postInProgress--;
    if (_postInProgress==0) 
    {
    _PostInProgressMutex->signal();
    }
    _PostMutex->release();

    return _notEmpty->signal();
}

int MsgQ::Pend(Message*& msg)
{

    _PendMutex->acquire();
    _pendInProgress++;
    _PendMutex->release();

    _mut->acquire();
    while (empty) 
    _notEmpty->wait();

    if (!_disconnectInProgress)
    {
    _queuePop(msg);
    }
    _mut->release();

    _PendMutex->acquire();
    _pendInProgress--;
    if (_pendInProgress == 0)
    {
    _PendInProgressMutex->signal();
    }
    _PendMutex->release();

    return _notFull->signal();
}

void MsgQ::_deleteQueue ()
{
    _PostMutex->acquire();
    if (_postInProgress != 0)
    {
    _PostMutex->release();
    TRACE("Acquiring Mutex.");
    _mut->acquire();
    full = 0;
    _notFull->broadcast();
    _mut->release();
    _PostInProgressMutex->wait();
    }
    else
    {
    _PostMutex->release();
    }

    _PendMutex->acquire();
    if (_pendInProgress != 0)
    {
    _PendMutex->release();
    TRACE("Acquiring Mutex.");
    _mut->acquire();
    empty = 0;
    _notEmpty->broadcast();
    _mut->release();
    _PendInProgressMutex->wait();
    }
    else
    {
    _PendMutex->release();
    }
}

void MsgQ::_initQueue()
{
    _ptrQueue = (Message **)(malloc (size * sizeof (Message*)));

    if (_ptrQueue == NULL)
    {
    cout << "queue could not be created!" << endl;
    }
    else
    {
    for (int i = 0; i < size; i++)
        *(_ptrQueue + i) = NULL;
    empty = 1;
    full = 0;
    head = 0;
    tail = 0;

        try{
        _mut = new ACE_Mutex() ;
        _notFull = new ACE_Condition<ACE_Mutex>(*_mut);
        _notEmpty = new ACE_Condition<ACE_Mutex>(*_mut); 

    _PostMutex = new ACE_Mutex();
    _PendMutex = new ACE_Mutex();
    _PostInProgressMutex = new ACE_Condition<ACE_Mutex>(*_PostMutex);
    _PendInProgressMutex = new ACE_Condition<ACE_Mutex>(*_PendMutex);
    _DisconnectMutex = new ACE_Mutex();

    _postInProgress = 0;
    _pendInProgress = 0;
    _disconnectInProgress = false;

        }catch(...){
            cout << "you should not be here" <<  endl;
        }
    }
}

Answer 1

代码似乎有很多问题所以我建议重新编写代码：

您可能会遇到死锁，因为在_mut和Post函数进入等待状态之前，您正在获取Pend。
我建议不要在acquire上使用release和ACE_Mutex，而是在创建时使用ACE_Guard类acquire mutex并在发布时释放它破坏。
为什么不使用ACE_Message_Queue而不是创建自己的？

无法获取ACE_Condition等待持有的互斥锁

1 个答案: