The Progress Counter is a lightweight tool class for counting the progress of some random amount of tasks.
Let's imagine you have a visual progress bar which displays some of next: progress of connection with network server, massive operations with files on hard disk, loading the game level; the reasonably question is how smoothly display the progress of such long tasks. More than, the real number of tasks and its complexity is real unknown, it different at any time. But you wish to display the smooth progress in this situation.
"It will be great to design some tiny object, like std::shared_ptr, which may be placed into task and notify me that task is finished on its destructor!"
Indeed! The ProgressCounter is designed for such situations. The instance of ProgressCounter (just counter) can produce the goals (aka instances of ProgressGoal). When the goal is attempted to be destroyed, it notifies the its host counter to update the state of progress. User can produce as much goals as he need using any of two ways: direct production from counter or proxied production from any goal.
Internally it based on std::shared_ptr, so, if you believe to the description of standard, using of goals is thread-safe.
More than, the operations with progress counter are secured with critical section, what make entire work to be thread-safe.
Inside of "/tests/test-concurrency/" folder the example of concurrency counting is placed.
The minimum what user have to do is to allocate the counter:
auto counter = ps::ProgressCounter::Create();After that user only have to allocate some goals:
auto goal = counter->ProduceGoal();
auto goal2 = goal->GetHostCounter()->ProduceGoal();That is all. Polling of counter will give the value of progress. Each time the goal is destroyed, the value of progress will be updated in the counter.
Indeed, the current version of code is far from ideal. It uses allocation on heap, it needs the critical section, it may be improved by using more features of c++14, smth else? So here the future plans:
- Get rid of
SharedProgressGoal, make the goal to be safely movable without affecting the progress. - Use more features of c++14
- Use the
atomicvalues and getting rid of critical section.