CODEWITHSUNDEEP
c++multithreadingvisual-studio-2010opencv
Domenico
Domenico

Reputation: 292

Visual C++ A queue of Mat images elements: how?

I try to do a queue of Mat images elements, but Visual C++ give me an error about "tipe" of queue.

I want to have an concurrent queue of OpenCV Mat images for use it with multiple threads.

How can I do this?

This is the code of the queue give me error (created about an example see in this forum):

template<data Mat>
 class coda_concorr
  {
  private:
std::queue<Mat> la_coda;
HANDLE mutex;
public:
void push(Mat const& data)
{
    WaitForSingleObject(mutex,INFINITE):
    la_coda.push(data);
    RelaseMutex(mutex);
}
bool vuota() const
{
    WaitForSingleObject(mutex,INFINITE);
    return la_coda.empty();
    ReleaseMutex(mutex);
}

bool try_pop(Mat& popped)
{
    WaitForSingleObject(mutex,INFINITE);
    if (la_coda.empty())
    {
        return false;
    }
    popped = la_coda.front();
    la_coda.pop();
    return true;
}

void aspetta_per_pop(Mat& popped)
{
    WaitForSingleObject(mutex,INFINITE);
    while (la_coda.empty())
    {
        WaitForSingleObject(mutex,INFINITE);
    }
    popped=la_coda.front();
    la_coda.pop();
}
};

I use Visual Studio 2010 and OpenCV 2.4.4

Upvotes: 0

Views: 1391

Answers (2)

juanchopanza
juanchopanza

Reputation: 227468

This is invalid template syntax:

template<data Mat>
class coda_concorr { .... };

You are not using any template parameters in your class, so you could make it a non-template. But it would make more sense to make it a template, and replace Mat by the template parameter.

template<typename T>
class coda_concorr
{
 private:
  std::queue<T> la_coda;
  ....
 public:
  void push(T const& data) { .... }
};

then, you can instantiate the template for a cv::Mat:

coda_concorr<cv::Mat> matQueue;

or a different type, this being the point of making the class a template in the first place:

coda_concorr<int> intQueue;
coda_concorr<std::string> stringQueue;

Upvotes: 1

Ralph Tandetzky
Ralph Tandetzky

Reputation: 23640

If I were you, I'd use a third-party library for a concurrent queue, because writing efficient thread-safe code is considered hard. I can recommend the PPL library from Microsoft or the TBB library from Intel.

Upvotes: 1

Related Questions