thread-pool.h

/**
 * File: thread-pool.h
 * -------------------
 * This class defines the ThreadPool class, which accepts a collection
 * of thunks (which are zero-argument functions that don't return a value)
 * and schedules them in a FIFO manner to be executed by a constant number
 * of child threads that exist solely to invoke previously scheduled thunks.
 */

#ifndef _thread_pool__
#define _thread_pool__

#include <cstdlib>
#include <functional>

class ThreadPool {
 public:

/**
 * Constructs a ThreadPool configured to spawn up to the specified
 * number of threads.
 */
  ThreadPool(size_t numThreads);

/**
 * Destroys the ThreadPool class
 */
  ~ThreadPool();

/**
 * Schedules the provided thunk (which is something that can
 * be invoked as a zero-argument function without a return value)
 * to be executed by one of the ThreadPool's threads as soon as
 * all previously scheduled thunks have been handled.
 */
  void schedule(const std::function<void(void)>& thunk);

/**
 * Blocks and waits until all previously scheduled thunks
 * have been executed in full.
 */
  void wait();

 private:
  class ThreadPoolImpl *impl;

  ThreadPool(const ThreadPool& original) = delete;
  ThreadPool& operator=(const ThreadPool& rhs) = delete;
};

#endif