threadpool: submitMany

Author: furszy

src/test/threadpool_tests.cpp

@@ -263,6 +263,24 @@ BOOST_AUTO_TEST_CASE(threadpool_basic)
         // Pool should be stopped and no workers remaining
         BOOST_CHECK_EQUAL(threadPool.WorkersCount(), 0);
     }
+
+    // Testing multi-task submission.
+    // Note: Tasks can even return different types!
+    {
+        ThreadPool threadPool(POOL_NAME);
+        threadPool.Start(NUM_WORKERS_DEFAULT);
+
+        const auto futures = threadPool.SubmitMany(
+                []() { std::cout << "Hi" << std::endl; },
+                []() { std::cout << "Andrew" << std::endl; },
+                []() { return 1; },
+                []() { return "different return type"; }
+        );
+
+        for (auto& fut : futures) {
+            fut.wait();
+        }
+    }
 }
 
 BOOST_AUTO_TEST_SUITE_END()

src/util/threadpool.h

@@ -161,6 +161,31 @@ class ThreadPool {
         return future;
     }
 
+    template<class... Fs> EXCLUSIVE_LOCKS_REQUIRED(!m_mutex)
+    auto SubmitMany(Fs&&... fns)
+    {
+        std::vector<std::future<void>> futures;
+        futures.reserve(sizeof...(Fs));
+
+        {
+            LOCK(m_mutex);
+            if (m_interrupt || m_workers.empty()) {
+                throw std::runtime_error("No active workers; cannot accept new tasks");
+            }
+
+            auto enqueue = [&](auto&& fn) EXCLUSIVE_LOCKS_REQUIRED(m_mutex) {
+                std::packaged_task<void()> task{std::forward<decltype(fn)>(fn)};
+                futures.emplace_back(task.get_future());
+                m_work_queue.emplace(std::move(task));
+            };
+
+            (enqueue(std::forward<Fs>(fns)), ...);
+        }
+
+        m_cv.notify_all();
+        return futures;
+    }
+
     /**
      * @brief Execute a single queued task synchronously.
      * Removes one task from the queue and executes it on the calling thread.