Use null util::function instead of a stop_execution exception when stopping threadpool threads to prevent exceptions from triggering when debugging

libs/async/include/psemek/async/executor.hpp

@@ -4,7 +4,6 @@
 #include <psemek/util/function.hpp>
 
 #include <chrono>
-#include <memory>
 
 namespace psemek::async
 {

libs/async/include/psemek/async/threadpool.hpp

@@ -4,7 +4,6 @@
 #include <psemek/util/thread.hpp>
 #include <psemek/util/synchronyzed_queue.hpp>
 
-#include <future>
 #include <vector>
 #include <string>
 #include <mutex>

libs/async/source/threadpool.cpp

@@ -9,13 +9,6 @@
 namespace psemek::async
 {
 
-	namespace
-	{
-
-		struct stop_execution{};
-
-	}
-
 	threadpool::threadpool(std::string const & name, std::size_t thread_count)
 		: working_count_{0}
 	{
@@ -25,10 +18,13 @@ namespace psemek::async
 			threads_.emplace_back([this, tname = std::move(tname)]() mutable
 			{
 				log::thread_registrator reg(std::move(tname));
-				for (bool running = true; running;)
+				while (true)
 				{
 					auto task = task_queue_.pop();
 
+					if (!task)
+						break;
+
 					{
 						std::lock_guard lock{working_count_mutex_};
 						++working_count_;
@@ -38,10 +34,6 @@ namespace psemek::async
 					{
 						task();
 					}
-					catch (stop_execution const &)
-					{
-						running = false;
-					}
 					catch (util::exception const & e)
 					{
 						log::error() << "Unhandled exception in threadpool executor: " << e;
@@ -86,7 +78,7 @@ namespace psemek::async
 		for (auto const & thread: threads_)
 		{
 			unused(thread);
-			task_queue_.push([]{ throw stop_execution{}; });
+			task_queue_.push(nullptr);
 		}
 		threads_.clear();
 	}