moved examples from various repos here

Author: dok-net

examples/circular_queue_mp_test/mp_queue_test.cpp

@@ -0,0 +1,74 @@
+// circular_mp_test.cpp : This file contains the 'main' function. Program execution begins and ends there.
+//
+
+#include <iostream>
+#include <thread>
+#include <chrono>
+#include <vector>
+#include <circular_queue_mp.h>
+
+struct qitem
+{
+	// producer id
+	int id;
+	// monotonic increasing value
+	int val = 0;
+};
+
+constexpr int TOTALMESSAGESTARGET = 60000000;
+// reserve one thread as consumer
+const auto THREADS = std::thread::hardware_concurrency() / 2 - 1;
+const int MESSAGES = TOTALMESSAGESTARGET / THREADS;
+circular_queue<std::thread> threads(THREADS);
+circular_queue_mp<qitem> queue(threads.capacity()* MESSAGES / 10);
+std::vector<int> checks(threads.capacity());
+
+int main()
+{
+	using namespace std::chrono_literals;
+	std::cerr << "Utilizing " << THREADS << " producer threads" << std::endl;
+	for (int i = 0; i < threads.capacity(); ++i)
+	{
+		threads.push(std::thread([i]() {
+			for (int c = 0; c < MESSAGES;)
+			{
+				// simulate some load
+				auto start = std::chrono::system_clock::now();
+				while (std::chrono::system_clock::now() - start < 1us);
+				if (queue.push({ i, c }))
+				{
+					++c;
+				}
+				else
+				{
+					//std::cerr << "queue full" << std::endl;
+					//std::this_thread::sleep_for(10us);
+				}
+				//if (0 == c % 10000) std::this_thread::sleep_for(10us);
+			}
+			}));
+	}
+	for (int o = 0; o < threads.available() * MESSAGES; ++o)
+	{
+		auto now = std::chrono::system_clock::now();
+		while (!queue.available())
+		{
+			auto starvedFor = std::chrono::system_clock::now() - now;
+			if (starvedFor > 20s) std::cerr << "queue starved for > 20s" << std::endl;
+			//std::this_thread::sleep_for(20ms);
+		}
+		auto item = queue.pop();
+		if (checks[item.id] != item.val)
+		{
+			std::cerr << "item mismatch" << std::endl;
+		}
+		checks[item.id] = item.val + 1;
+		if (0 == item.val % 1000) std::this_thread::sleep_for(100us);
+	}
+	while (threads.available())
+	{
+		auto thread = threads.pop();
+		thread.join();
+	}
+	return 0;
+}