Tweak the shared ticket lock test

tests/shared-lock-test.cc

@@ -5,11 +5,11 @@
 
 #include <iostream>
 
-static constexpr std::size_t test_count = 20 * 1000;
+static constexpr std::size_t test_count = 10 * 1000 * 1000;
 
 static constexpr std::size_t table_size = 8;
 
-static constexpr std::size_t thread_num = 10;
+static constexpr std::size_t thread_num = 8;
 static_assert(thread_num < 16, "for testing purposes shared_ticket_lock is intentionally restricted to at most 15 threads.");
 
 struct entry
@@ -32,7 +32,7 @@ thread_routine(std::size_t thread_idx)
 		table_lock.unlock_shared();
 
 		table_lock.lock();
-		if ((i % 1000) == 0)
+		if ((i % 1000000) == 0)
 			std::cout << "thread #" << thread_idx << " " << i << "\n";
 		for (std::size_t j = 0; j < table_size; j++)
 			table[j].value++;
@@ -43,6 +43,12 @@ thread_routine(std::size_t thread_idx)
 int
 main()
 {
+	std::size_t hw_threads = std::thread::hardware_concurrency();
+	if (thread_num > hw_threads) {
+		std::cout << "WARNING: the test runs extremely slow if the number of CPU cores is below " << thread_num
+			  << " while your machine appears to have just " << hw_threads << ".\n";
+	}
+
 	evenk::thread thread_array[thread_num];
 	for (std::size_t i = 0; i < thread_num; i++)
 		thread_array[i] = evenk::thread(thread_routine, i);