Function main

example/asynchronous_echo_c++/client.cpp:52–110

                        

int main(int argc, char* argv[]) {
    // Parse gflags. We recommend you to use gflags as well.
    GFLAGS_NAMESPACE::ParseCommandLineFlags(&argc, &argv, true);

    // A Channel represents a communication line to a Server. Notice that 
    // Channel is thread-safe and can be shared by all threads in your program.
    brpc::Channel channel;

    // Initialize the channel, NULL means using default options.
    brpc::ChannelOptions options;
    options.protocol = FLAGS_protocol;
    options.connection_type = FLAGS_connection_type;
    options.timeout_ms = FLAGS_timeout_ms/*milliseconds*/;
    options.max_retry = FLAGS_max_retry;
    if (channel.Init(FLAGS_server.c_str(), FLAGS_load_balancer.c_str(), &options) != 0) {
        LOG(ERROR) << "Fail to initialize channel";
        return -1;
    }

    // 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(&channel);
    
    // Send a request and wait for the response every 1 second.
    int log_id = 0;
    while (!brpc::IsAskedToQuit()) {
        // Since we are sending asynchronous RPC (`done' is not NULL),
        // these objects MUST remain valid until `done' is called.
        // As a result, we allocate these objects on heap
        example::EchoResponse* response = new example::EchoResponse();
        brpc::Controller* cntl = new brpc::Controller();

        // Notice that you don't have to new request, which can be modified
        // or destroyed just after stub.Echo is called.
        example::EchoRequest request;
        request.set_message("hello world");

        cntl->set_log_id(log_id ++);  // set by user
        if (FLAGS_send_attachment) {
            // Set attachment which is wired to network directly instead of 
            // being serialized into protobuf messages.
            cntl->request_attachment().append("foo");
        }

        // We use protobuf utility `NewCallback' to create a closure object
        // that will call our callback `HandleEchoResponse'. This closure
        // will automatically delete itself after being called once
        google::protobuf::Closure* done = brpc::NewCallback(
            &HandleEchoResponse, cntl, response);
        stub.Echo(cntl, &request, response, done);

        // This is an asynchronous RPC, so we can only fetch the result
        // inside the callback
        sleep(1);
    }

    LOG(INFO) << "EchoClient is going to quit";
    return 0;