Method task_runner

src/bthread/task_group.cpp:351–481

#endif // BUTIL_USE_ASAN

void TaskGroup::task_runner(intptr_t skip_remained) {
    // NOTE: tls_task_group is volatile since tasks are moved around
    //       different groups.
    TaskGroup* g = tls_task_group;
#ifdef BRPC_BTHREAD_TRACER
    TaskTracer::set_running_status(g->tid(), g->_cur_meta);
#endif // BRPC_BTHREAD_TRACER

    if (!skip_remained) {
        while (g->_last_context_remained) {
            RemainedFn fn = g->_last_context_remained;
            g->_last_context_remained = NULL;
            fn(g->_last_context_remained_arg);
            g = BAIDU_GET_VOLATILE_THREAD_LOCAL(tls_task_group);
        }

#ifndef NDEBUG
        --g->_sched_recursive_guard;
#endif
    }

    do {
        // A task can be stopped before it gets running, in which case
        // we may skip user function, but that may confuse user:
        // Most tasks have variables to remember running result of the task,
        // which is often initialized to values indicating success. If an
        // user function is never called, the variables will be unchanged
        // however they'd better reflect failures because the task is stopped
        // abnormally.

        // Meta and identifier of the task is persistent in this run.
        TaskMeta* const m = g->_cur_meta;

        if (FLAGS_show_bthread_creation_in_vars) {
            // NOTE: the thread triggering exposure of pending time may spend
            // considerable time because a single bvar::LatencyRecorder
            // contains many bvar.
            g->_control->exposed_pending_time() <<
                (butil::cpuwide_time_ns() - m->cpuwide_start_ns) / 1000L;
        }

        // Not catch exceptions except ExitException which is for implementing
        // bthread_exit(). User code is intended to crash when an exception is
        // not caught explicitly. This is consistent with other threading
        // libraries.
        void* thread_return;
        try {
            thread_return = m->fn(m->arg);
        } catch (ExitException& e) {
            thread_return = e.value();
        }

        if (m->attr.flags & BTHREAD_INHERIT_SPAN) {
            if (g_end_bthread_span) {
                g_end_bthread_span();
            }
        }