Method dump_thread

src/bvar/collector.cpp:362–411

Call user's callbacks in this thread.

// Call user's callbacks in this thread.
void Collector::dump_thread() {
    int64_t last_ns = butil::cpuwide_time_ns();

    // vars
    double busy_seconds = 0;
    bvar::PassiveStatus<double> busy_seconds_var(deref_value<double>, &busy_seconds);
    bvar::PerSecond<bvar::PassiveStatus<double> > busy_seconds_second(
        "bvar_collector_dump_thread_usage", &busy_seconds_var);

    bvar::PassiveStatus<int64_t> ndumped_var(deref_value<int64_t>, &_ndump);
    bvar::PerSecond<bvar::PassiveStatus<int64_t> > ndumped_second(
        "bvar::collector_dump_second", &ndumped_var);

    butil::LinkNode<Collected> root;
    size_t round = 0;

    // The main loop
    while (!_stop) {
        ++round;
        // Get new samples set by grab_thread.
        butil::LinkNode<Collected>* newhead = NULL;
        {
            BAIDU_SCOPED_LOCK(_dump_thread_mutex);
            while (!_stop && _dump_root.next() == &_dump_root) {
                const int64_t now_ns = butil::cpuwide_time_ns();
                busy_seconds += (now_ns - last_ns) / 1000000000.0;
                pthread_cond_wait(&_dump_thread_cond, &_dump_thread_mutex);
                last_ns = butil::cpuwide_time_ns();
            }
            if (_stop) {
                break;
            }
            newhead = _dump_root.next();
            _dump_root.RemoveFromList();
        }
        CHECK(newhead != &_dump_root);
        newhead->InsertBeforeAsList(&root);

        // Call callbacks.
        for (butil::LinkNode<Collected>* p = root.next(); !_stop && p != &root;) {
            // We remove p from the list, save next first.
            butil::LinkNode<Collected>* saved_next = p->next();
            p->RemoveFromList();
            Collected* s = p->value();
            s->dump_and_destroy(round);
            ++_ndump;
            p = saved_next;
        }
    }
}

// Submit a sample for asynchronous dumping. The Collector holds only the Collected*
// pointer (e.g., SpanContainer*). Regardless of which branch is taken below, the