QList thread safety

Kayote

hello, I have a question about thread-safety as I want to use a QList across multiple threads. Normally you would use a QMutex for this, but I dont want to have to create a new QMutex object for every list I want to use and call lock/unlock manually at each place, so I had the idea to make my own "List" class which uses QList.

This is the code:

template <class T>
class ThreadSafeList
{
public:
    ThreadSafeList();

    void append(const T &value)
    {
        mutex.lock();
        list.append(value);
        mutex.unlock();
    }

    void removeAt(int i)
    {
        mutex.lock();
        list.removeAt(i);
        mutex.unlock();
    }

    int count()
    {
        mutex.lock();
        int count = list.count();
        mutex.unlock();
        return count;
    }

private:
    QList<T> list;
    QMutex mutex;
};

so my question is if this would actually be considered thread-safe and if this could be used without any problems across many threads? or is there a better solution?

Christian Ehrlicher

As long as you only use those three functions (which I doubt) it's fine although I would prefer a mutex outside the QList instead. And I would use a QMutexLocker instead manual lock/unlock.