Method sync_client

tools/rpc_press/rpc_press_impl.cpp:220–264

static butil::atomic<int> g_thread_count(0);

void RpcPress::sync_client() {
    double req_rate = _options.test_req_rate / _options.test_thread_num;
    //max make up time is 5 s
    if (_msgs.empty()) {
        LOG(ERROR) << "nothing to send!";
        return;
    }
    const int thread_index = g_thread_count.fetch_add(1, butil::memory_order_relaxed);
    int msg_index = thread_index;
    int64_t last_expected_time = butil::monotonic_time_ns();
    const int64_t interval = (int64_t) (1000000000L / req_rate);
    // the max tolerant delay between end_time and expected_time. 10ms or 10 intervals
    int64_t max_tolerant_delay = std::max((int64_t) 10000000L, 10 * interval);    
    while (!_stop) {
        brpc::Controller* cntl = new brpc::Controller;
        msg_index = (msg_index + _options.test_thread_num) % _msgs.size();
        Message* request = _msgs[msg_index];
        Message* response = _pbrpc_client->get_output_message();
        const int64_t start_time = butil::cpuwide_time_us();
        google::protobuf::Closure* done = brpc::NewCallback<
            RpcPress, 
            RpcPress*, 
            brpc::Controller*, 
            Message*, 
            Message*, int64_t>
            (this, &RpcPress::handle_response, cntl, request, response, start_time);
        const brpc::CallId cid1 = cntl->call_id();
        _pbrpc_client->call_method(cntl, request, response, done);
        _sent_count << 1;

        if (_options.test_req_rate <= 0) { 
            brpc::Join(cid1);
        } else {
            int64_t end_time = butil::monotonic_time_ns();
            int64_t expected_time = last_expected_time + interval;
            if (end_time < expected_time) {
                usleep((expected_time - end_time)/1000);
            }
            if (end_time - expected_time > max_tolerant_delay) {
                expected_time = end_time;
            }            
            last_expected_time = expected_time;
        }
    }
}

int RpcPress::start() {
    _ttid.resize(_options.test_thread_num);