• Introduction
  • ThreadPool
  • BlockingQueue
• Installation

Introduction

My collection of Concurrency related header-only classes while going through C++ Concurrency in Action book. Following is the brief description of classes

ThreadPool

A thread pool to manage a group of worker threads to execute tasks - It expects a template parameter for the underlying container to store tasks:

• By default, it uses BlockingQueue to store and extract tasks
• Otherwise, PriorityQueue is another candidate for underlying queue

Threadpool permits concurrent invocation of add_task member methods and other helper methods

• except stop and stop_early
• and methods which permit concurrent invocation have been annotated with thread_safe

BlockingQueue

A std::condition_variable based BlockingQueue to hold tasks in a queue and supports following methods:

• push to push an item (task) on the queue
• pop waits for std::chrono::milliseconds::max() for an element to be on queue to pop, otherwise throws std::runtime_error
• try_pop_for waits for a user specified time interval for an element to be on queue and returns a pair:
  • pair.first is a std::unique_ptr containing the item, otherwise nullptr if there was nothing in the queue
  • pair.second returns true if queue has been closed, otherwise false
• try_pop like try_pop_for, only difference is that it tries for _wait_time milliseconds (set in constructor)

Following is the class template details

• tparam T: type of tasks, can be either executables or executables wrapped inside PriorityWrapper to add priority
• tparam Container: std::queue<T> or std::multiset<T>, not any other container. This is enforced in constructor std::multiset<T> is supported in case item has a priority (e.g. wrapped inside PriorityWrapper)

Installation

As the classes are header-only, user can simply copy the include directory and use in their projects.