Method start_background

src/bthread/task_group.cpp:564–613

template <bool REMOTE>
int TaskGroup::start_background(bthread_t* __restrict th,
                                const bthread_attr_t* __restrict attr,
                                void * (*fn)(void*),
                                void* __restrict arg) {
    if (__builtin_expect(!fn, 0)) {
        return EINVAL;
    }
    const int64_t start_ns = butil::cpuwide_time_ns();
    const bthread_attr_t using_attr = (attr ? *attr : BTHREAD_ATTR_NORMAL);
    butil::ResourceId<TaskMeta> slot;
    TaskMeta* m = butil::get_resource(&slot);
    if (BAIDU_UNLIKELY(NULL == m)) {
        return ENOMEM;
    }
    CHECK(m->current_waiter.load(butil::memory_order_relaxed) == NULL);
    m->sleep_failed = false;
    m->stop = false;
    m->interrupted = false;
    m->about_to_quit = false;
    m->fn = fn;
    m->arg = arg;
    CHECK(m->stack == NULL);
    m->attr = using_attr;
    m->local_storage = LOCAL_STORAGE_INIT;
    if (using_attr.flags & BTHREAD_INHERIT_SPAN) {
        if (g_create_bthread_span) {
            m->local_storage.rpcz_parent_span = g_create_bthread_span();
        } else {
            m->local_storage.rpcz_parent_span = BAIDU_GET_VOLATILE_THREAD_LOCAL(tls_bls).rpcz_parent_span;
        }
    }
    m->cpuwide_start_ns = start_ns;
    m->stat = EMPTY_STAT;
    m->tid = make_tid(*m->version_butex, slot);
    *th = m->tid;
    if (using_attr.flags & BTHREAD_LOG_START_AND_FINISH) {
        LOG(INFO) << "Started bthread " << m->tid;
    }
    _control->_nbthreads << 1;
    _control->tag_nbthreads(tag()) << 1;
#ifdef BRPC_BTHREAD_TRACER
    _control->_task_tracer.set_status(TASK_STATUS_CREATED, m);
#endif // BRPC_BTHREAD_TRACER
    if (REMOTE) {
        ready_to_run_remote(m, (using_attr.flags & BTHREAD_NOSIGNAL));
    } else {
        ready_to_run(m, (using_attr.flags & BTHREAD_NOSIGNAL));
    }
    return 0;
}

// Explicit instantiations.
template int