Method Join

src/brpc/server.cpp:1305–1353

NOTE: Join() can happen before Stop().

// NOTE: Join() can happen before Stop().
int Server::Join() {
    if (_status != RUNNING && _status != STOPPING) {
        return -1;
    }
    if (_am) {
        _am->Join();
    }
    if (_internal_am) {
        _internal_am->Join();
    }

    if (_session_local_data_pool) {
        // We can't delete the pool right here because there's a bvar watching
        // this pool in _derivative_thread which does not quit yet.
        _session_local_data_pool->Reset(NULL);
    }

    if (_keytable_pool) {
        // Destroy _keytable_pool to delete keytables inside. This has to be
        // done here (before leaving Join) because it's legal for users to
        // delete bthread keys after Join which makes related objects
        // in KeyTables undeletable anymore and leaked.
        CHECK_EQ(0, bthread_keytable_pool_destroy(_keytable_pool));
        // TODO: Can't delete _keytable_pool which may be accessed by
        // still-running bthreads (created by the server). The memory is
        // leaked but servers are unlikely to be started/stopped frequently,
        // the leak is acceptable in most scenarios.
        _keytable_pool = NULL;
    }

    // Delete tls_key as well since we don't need it anymore.
    if (_tl_options.tls_key != INVALID_BTHREAD_KEY) {
        CHECK_EQ(0, bthread_key_delete(_tl_options.tls_key));
        _tl_options.tls_key = INVALID_BTHREAD_KEY;
    }

    // Have to join _derivative_thread, which may assume that server is running
    // and services in server are not mutated, otherwise data race happens
    // between Add/RemoveService after Join() and the thread.
    if (_derivative_thread != INVALID_BTHREAD) {
        bthread_stop(_derivative_thread);
        bthread_join(_derivative_thread, NULL);
        _derivative_thread = INVALID_BTHREAD;
    }

    g_running_server_count.fetch_sub(1, butil::memory_order_relaxed);
    _status = READY;
    return 0;
}

int Server::AddServiceInternal(google::protobuf::Service* service,
                               bool is_builtin_service,