How to make push and pop on queue atomic, how to lock those operations?

boost, c++, multithreading, queue, stl

Solution

Probably the most portable non-C++11 locking mechanism is are the synchronisztion types from the Boost.Thread library. In particular the mutex class gives you a simple lockable object for giving exclusive access to a resource. For example:

#include <boost/thread/mutex.hpp>
#include <queue>

template <typename T>
class locking_queue {
public:
    void push(T const & value) {
        boost::mutex::scoped_lock lock(mutex);
        queue.push(value);
    }

    bool pop(T & value) {
        boost::mutex::scoped_lock lock(mutex);
        if (queue.empty()) {
            return false;
        } else {
            value = queue.front();
            queue.pop();
            return true;
        }
    }

private:
    std::queue<T> queue;
    boost::mutex mutex;
};

Another advantage is that this is quite similar to the C++11 `std::mutex` class, which will make conversion quite straightforward if you decide to use that instead.

Problem

Original source