第28章-主模块业务结构搭建

首先我们要在主线程中，启动3个UDP Server线程，这个是提供业务层/API层的服务。然后分别启动report_client线程，用来和reporter Service进行通信，将请求上报信息发送给Reporter Service。 然后再启动dns_client线程，用来和dns service通信。

lars_loadbalance_agent/include/main_server.h

#pragma once
#include "lars_reactor.h"
#include "lars.pb.h"
//与report_client通信的thread_queue消息队列
extern thread_queue<lars::ReportStatusRequest>* report_queue;
//与dns_client通信的thread_queue消息队列
extern thread_queue<lars::GetRouteRequest>* dns_queue;
// 启动udp server服务,用来接收业务层(调用者/使用者)的消息
void start_UDP_servers(void);
// 启动lars_reporter client 线程
void start_report_client(void);
// 启动lars_dns client 线程
void start_dns_client(void);

lars_loadbalance_agent/src/main_server.cpp

#include "main_server.h"
#include "lars.pb.h"
//与report_client通信的thread_queue消息队列
thread_queue<lars::ReportStatusRequest>* report_queue = NULL;
//与dns_client通信的thread_queue消息队列
thread_queue<lars::GetRouteRequest>* dns_queue = NULL;
int main(int argc, char **argv)
{
    //1 加载配置文件
    //2 启动udp server服务,用来接收业务层(调用者/使用者)的消息
    start_UDP_servers();
    //3 启动lars_reporter client 线程
    report_queue = new thread_queue<lars::ReportStatusRequest>();
    if (report_queue == NULL) {
        fprintf(stderr, "create report queue error!\n");
        exit(1);
    }
    start_report_client();
    //4 启动lars_dns client 线程
    dns_queue = new thread_queue<lars::GetRouteRequest>();
    if (dns_queue == NULL) {
        fprintf(stderr, "create dns queue error!\n");
        exit(1);
    }
    start_dns_client();
    std::cout <<"done!" <<std::endl;
    while (1) {
        sleep(10);
    }
    return 0;
}

这里我们分别在main()中 ，开启以上线程。

    其中`report_client`线程需要携带`thread_queue<lars::ReportStatusRequest>`消息队列通道。`agent`负责将上报请求消息`lars::ReportStatusRequest`通过thread_queue发送给reporter service。
    其中`dns_client`线程需要携带`thread_queue<lars::GetRouteRequest>`。`agent`负责将请求modid/cmdid的route消息`lars::GetRouteRequest`通过thread_queue发送给dns service。

3个udp server的线程开辟实现如下：

lars_loadbalance_agent/src/agent_udp_server.cpp

#include "lars_reactor.h"
#include "main_server.h"
void * agent_server_main(void * args)
{
    int *index = (int*)args;
    short port = *index + 8888;
    event_loop loop;
    udp_server server(&loop, "0.0.0.0", port);
    //TODO 给server注册消息分发路由业务
    printf("agent UDP server :port %d is started...\n", port);
    loop.event_process();
    return NULL;
}
void start_UDP_servers(void)
{
    for (int i = 0; i < 3; i ++) {
        pthread_t tid;
        int ret = pthread_create(&tid, NULL, agent_server_main, &i);
        if (ret == -1) {
            perror("pthread_create");
            exit(1);
        }
        pthread_detach(tid);
    }
}

reporter thread创建实现如下：

lars_loadbalance_agent/src/reporter_client.cpp

#include "lars_reactor.h"
#include "main_server.h"
#include <pthread.h>
void *report_client_thread(void* args)
{
    printf("report client thread start\n");
#if 0
    event_loop loop;
    //1 加载配置文件得到repoter ip + port
    std::string ip = config_file::instance()->GetString("reporter", "ip", "");
    short port = config_file::instance()->GetNumber("reporter", "port", 0);
    //2 创建客户端
    tcp_client client(&loop, ip.c_str(), port, "reporter client");
    //3 将 thread_queue消息回调事件，绑定到loop中
    report_queue->set_loop(&loop);
    report_queue->set_callback()
    //4 启动事件监听
    loop.event_process();
#endif
    return NULL;
}
void start_report_client()
{
    //开辟一个线程
    pthread_t tid;
    //启动线程业务函数
    int ret = pthread_create(&tid, NULL, report_client_thread, NULL);
    if (ret == -1) {
        perror("pthread_create");
        exit(1);
    }
    //设置分离模式
    pthread_detach(tid);
}

dns thread创建实现如下：

lars_loadbalance_agent/src/dns_client.cpp

#include "lars_reactor.h"
#include "main_server.h"
#include <pthread.h>
void *dns_client_thread(void* args)
{
    printf("dns client thread start\n");
    return NULL;
}
void start_dns_client()
{
    //开辟一个线程
    pthread_t tid;
    //启动线程业务函数
    int ret = pthread_create(&tid, NULL, dns_client_thread, NULL);
    if (ret == -1) {
        perror("pthread_create");
        exit(1);
    }
    //设置分离模式
    pthread_detach(tid);
}

编译，然后我们简单启动一下./bin/lars_lb_agent

$ ./bin/lars_lb_agent 
dns client thread start
report client thread start
done!
msg_router init...
server on 0.0.0.0:8888 is running...
agent UDP server :port 8888 is started...
msg_router init...
server on 0.0.0.0:8888 is running...
agent UDP server :port 8888 is started...
msg_router init...
server on 0.0.0.0:8888 is running...
agent UDP server :port 8888 is started...
...