Method initPerformanceCounters

src/Interpreters/ThreadStatusExt.cpp:209–262

}

void ThreadStatus::initPerformanceCounters()
{
    performance_counters_finalized = false;

    /// Clear stats from previous query if a new query is started
    /// TODO: make separate query_thread_performance_counters and thread_performance_counters
    performance_counters.resetCounters();
    memory_tracker.resetCounters();
    memory_tracker.setDescription("(for thread)");

    // query_start_time_{microseconds, nanoseconds} are all constructed from the same time point
    // to ensure that they are all equal up to the precision of a second.
    const auto now = std::chrono::system_clock::now();

    query_start_time_nanoseconds = time_in_nanoseconds(now);
    query_start_time = time_in_seconds(now);
    query_start_time_microseconds = time_in_microseconds(now);
    ++queries_started;

    // query_start_time_nanoseconds cannot be used here since RUsageCounters expect CLOCK_MONOTONIC
    *last_rusage = RUsageCounters::current();

    if (auto query_context_ptr = query_context.lock())
    {
        const Settings & settings = query_context_ptr->getSettingsRef();
        if (settings.metrics_perf_events_enabled)
        {
            try
            {
                current_thread_counters.initializeProfileEvents(
                    settings.metrics_perf_events_list);
            }
            catch (...)
            {
                tryLogCurrentException(__PRETTY_FUNCTION__);
            }
        }
    }

    if (!taskstats)
    {
        try
        {
            if (auto query_context_ptr = query_context.lock(); query_context_ptr && query_context_ptr->getSettingsRef().enable_os_task_stats)
                taskstats = TasksStatsCounters::create(thread_id);
        }
        catch (...)
        {
            tryLogCurrentException(log);
        }
    }
    if (taskstats)
        taskstats->reset();
}

void ThreadStatus::finalizePerformanceCounters()
{