Function sender

example/selective_echo_c++/client.cpp:46–85

bvar::Adder<int> g_error_count("client_error_count");

static void* sender(void* arg) {
    // Normally, you should not call a Channel directly, but instead construct
    // a stub Service wrapping it. stub can be shared by all threads as well.
    example::EchoService_Stub stub(static_cast<google::protobuf::RpcChannel*>(arg));

    int log_id = 0;
    while (!brpc::IsAskedToQuit()) {
        // We will receive response synchronously, safe to put variables
        // on stack.
        example::EchoRequest request;
        example::EchoResponse response;
        brpc::Controller cntl;

        request.set_message(g_request);
        cntl.set_log_id(log_id++);  // set by user

        if (!g_attachment.empty()) {
            // Set attachment which is wired to network directly instead of 
            // being serialized into protobuf messages.
            cntl.request_attachment().append(g_attachment);
        }

        // Because `done'(last parameter) is NULL, this function waits until
        // the response comes back or error occurs(including timedout).
        stub.Echo(&cntl, &request, &response, NULL);
        const int64_t elp = cntl.latency_us();
        if (!cntl.Failed()) {
            g_latency_recorder << cntl.latency_us();
        } else {
            g_error_count << 1; 
            CHECK(brpc::IsAskedToQuit() || !FLAGS_dont_fail)
                << "error=" << cntl.ErrorText() << " latency=" << elp;
            // We can't connect to the server, sleep a while. Notice that this
            // is a specific sleeping to prevent this thread from spinning too // fast. You should continue the business logic in a production 
            // server rather than sleeping.
            bthread_usleep(50000);
        }
    }
    return NULL;
}

int main(int argc, char* argv[]) {
    // Parse gflags. We recommend you to use gflags as well.