Function check_pausing

tests/BS_thread_pool_test.cpp:2090–2118

* @brief Check that pausing works. */

 * @brief Check that pausing works.
 */
void check_pausing()
{
    constexpr std::chrono::milliseconds sleep_time(200);
    BS::pause_thread_pool pool;
    logln("Checking that the pool correctly reports that it is not paused after construction...");
    check(!pool.is_paused());
    logln("Pausing pool.");
    pool.pause();
    logln("Checking that the pool correctly reports that it is paused...");
    check(pool.is_paused());
    logln("Submitting task and waiting.");
    std::atomic<bool> flag = false;
    pool.detach_task(
        [&flag]
        {
            flag = true;
            logln("Task executed.");
        });
    std::this_thread::sleep_for(sleep_time);
    logln("Verifying that the task has not been executed...");
    check(!flag);
    logln("Unpausing pool and waiting.");
    pool.unpause();
    std::this_thread::sleep_for(sleep_time);
    logln("Verifying that the task has been executed...");
    check(flag);
    logln("Checking that the pool correctly reports that it is not paused...");
    check(!pool.is_paused());
}

/**
 * @brief Check that purge() works.