Rewrite executor to template & come back executor unit tests

lib/main/concurrent/executor.h

@@ -27,12 +27,18 @@
  * @brief Thread pools address two different problems: they usually provide improved performance when executing large
  * numbers of asynchronous tasks, due to reduced per-task invocation overhead, and they provide a means of bounding and
  * managing the resources, including threads, consumed when executing a collection of tasks.
+ *
+ * TODO adapt documentation to template
  */
-class PIThreadPoolExecutor {
+template <typename Thread_, typename Dequeue_>
+class PIThreadPoolExecutorTemplate {
 public:
-	explicit PIThreadPoolExecutor(size_t corePoolSize = 1, PIBlockingDequeue<std::function<void()> >* taskQueue_ = new PIBlockingDequeue<std::function<void()> >());
+	explicit PIThreadPoolExecutorTemplate(size_t corePoolSize = 1) : isShutdown_(false) { makePool(corePoolSize); }
 
-	virtual ~PIThreadPoolExecutor();
+	virtual ~PIThreadPoolExecutorTemplate() {
+		shutdownNow();
+		while (threadPool.size() > 0) delete threadPool.take_back();
+	}
 
 	/**
 	 * @brief Executes the given task sometime in the future. The task execute in an existing pooled thread. If the task
@@ -41,24 +47,65 @@ public:
 	 *
 	 * @param runnable not empty function for thread pool execution
 	 */
-	void execute(const std::function<void()>& runnable);
-
-	void shutdownNow();
+	void execute(const std::function<void()> &runnable) {
+		if (!isShutdown_) taskQueue.offer(runnable);
+	}
 
 	/**
 	 * @brief Initiates an orderly shutdown in which previously submitted tasks are executed, but no new tasks will be
 	 * accepted. Invocation has no additional effect if already shut down. This method does not wait for previously
 	 * submitted tasks to complete execution. Use awaitTermination to do that.
 	 */
-	void shutdown();
+	void shutdown() {
+		isShutdown_ = true;
+	}
 
-	bool isShutdown() const;
+	void shutdownNow() {
+		isShutdown_ = true;
+		for (size_t i = 0; i < threadPool.size(); ++i) threadPool[i]->stop();
+	}
 
-	bool awaitTermination(int timeoutMs);
-private:
+	bool isShutdown() const {
+		return isShutdown_;
+	}
+
+	bool awaitTermination(int timeoutMs) {
+		PITimeMeasurer measurer;
+		for (size_t i = 0; i < threadPool.size(); ++i) {
+			int dif = timeoutMs - (int)measurer.elapsed_m();
+			if (dif < 0) return false;
+			if (!threadPool[i]->waitForFinish(dif)) return false;
+		}
+		return true;
+	}
+
+protected:
 	std::atomic_bool isShutdown_;
-	PIBlockingDequeue<std::function<void()> >* taskQueue;
-	PIVector<PIThread*> threadPool;
+	Dequeue_ taskQueue;
+	PIVector<Thread_*> threadPool;
+
+	template<typename Function>
+	PIThreadPoolExecutorTemplate(size_t corePoolSize, Function onBeforeStart) : isShutdown_(false) {
+		makePool(corePoolSize, onBeforeStart);
+	}
+
+	void makePool(size_t corePoolSize, std::function<void(Thread_*)> onBeforeStart = [](Thread_*){}) {
+		for (size_t i = 0; i < corePoolSize; ++i) {
+			auto* thread = new Thread_([&, i](){
+				auto runnable = taskQueue.poll(100);
+				if (runnable) {
+					runnable();
+				}
+				if (isShutdown_ && taskQueue.size() == 0) threadPool[i]->stop();
+			});
+			threadPool.push_back(thread);
+			onBeforeStart(thread);
+			thread->start();
+		}
+	}
 };
 
+typedef PIThreadPoolExecutorTemplate<PIThread, PIBlockingDequeue<std::function<void()> > > PIThreadPoolExecutor;
+
+
 #endif //PIP_TESTS_EXECUTOR_H