Checkpoint

daggy/include/daggy/ThreadPool.hpp

@@ -22,10 +22,12 @@ namespace daggy {
 
       std::future<void> addTask(AsyncTask fn);
     private:
+      using QueuedAsyncTask = std::shared_ptr<AsyncTask>;
+
       std::atomic<bool>        shutdown_;
       std::mutex               guard_;
       std::condition_variable  cv_;
       std::vector<std::thread> workers_;
-      std::deque<AsyncTask>    taskQueue_;
+      std::deque<QueuedAsyncTask>    taskQueue_;
   };
 }

daggy/src/ThreadPool.cpp

@@ -8,17 +8,16 @@ ThreadPool::ThreadPool(size_t nWorkers) {
   for (size_t i = 0; i < nWorkers; ++i) {
     workers_.emplace_back([&]() {
         while (true) {
-          AsyncTask tsk;
+          QueuedAsyncTask tsk;
-
           {
             std::unique_lock<std::mutex> lk(guard_);
             cv_.wait(lk, []{ return true; });
             if (shutdown_) return;
-            tsk = taskQueue_.front();
+            tsk.swap(taskQueue_.front());
             taskQueue_.pop_front();
           }
 
-          tsk();
+          (*tsk)();
         }
     });
   }
@@ -38,11 +37,12 @@ void ThreadPool::shutdown() {
 }
 
 std::future<void> ThreadPool::addTask(std::function<void()> fn) {
-  std::packaged_task<void()> task(fn);
+  auto task = std::make_shared<std::packaged_task<void()>>(fn);
-  std::future<void> result = task.get_future();
+  std::future<void> result = task->get_future();
   {
     std::unique_lock<std::mutex> lk(guard_);
-    taskQueue_.push_back(std::move(task));
+    taskQueue_.emplace_back(std::move(task));
   }
   cv_.notify_one();
+  return result;
 }