Tracking issue for the follow up comments in #22904. It seems that PR has introduced lock contentions, and/or the `checkqueue_tests` are now behaving very poorly, with long runtimes and generating GBs of log output in some cases. See comments starting here: https://github.com/bitcoin/bitcoin/pull/22904#issuecomment-930466935.

cc @ajtowns @theuni @martinus  
{
    auto queue = std::make_unique<Unique_Queue>(QUEUE_BATCH_SIZE);
    queue->StartWorkerThreads(SCRIPT_CHECK_THREADS);
    size_t COUNT = 100000;
    size_t total = COUNT;
    {
        CCheckQueueControl<UniqueCheck> control(queue.get());
        while (total) {
            size_t r = InsecureRandRange(10);
            std::vector<UniqueCheck> vChecks;
            for (size_t k = 0; k < r && total; k++)
                vChecks.emplace_back(--total);
            control.Add(vChecks);
        }
    }
    {
        LOCK(UniqueCheck::m);
        bool r = true;
        BOOST_REQUIRE_EQUAL(UniqueCheck::results.size(), COUNT);
        for (size_t i = 0; i < COUNT; ++i) {
            r = r && UniqueCheck::results.count(i) == 1;
        }
        BOOST_REQUIRE(r);
    }
    queue->StopWorkerThreads();
}
BOOST_AUTO_TEST_CASE(test_CheckQueue_Memory)