#include #include #include #include #include #include #include #include void record_cpu_usage() { static long prev_idle = 0; static long prev

可以将主函数中的 while 循环内容抽象成一个单独的函数，以提高代码的可读性和可维护性。以下是重构后的代码示例，其中 monitor_cpu_and_send_heartbeat 函数包含了原先 while 循环的逻辑：

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sys/timerfd.h>
#include <unistd.h>
#include <time.h>
#include <fcntl.h>  
#include <errno.h>

void record_cpu_usage() {
    static long prev_idle = 0;
    static long prev_total = 0;

    FILE *fp = fopen("/proc/stat", "r");
    if (!fp) {
        perror("fopen");
        return;
    }

    char buffer[256];
    fgets(buffer, sizeof(buffer), fp);
    
    // 从 /proc/stat 中读取CPU信息
    long user, nice, system, idle, iowait, irq, softirq;
    sscanf(buffer, "cpu %ld %ld %ld %ld %ld %ld %ld", &user, &nice, &system, &idle, &iowait, &irq, &softirq);

    // 计算总时间和空闲时间
    long total = user + nice + system + idle + iowait + irq + softirq;
    
    // 计算CPU占用率
    long diff_idle = idle - prev_idle;
    long diff_total = total - prev_total;

    if (diff_total > 0) {
        double cpu_usage = (double)(diff_total - diff_idle) / diff_total * 100.0;
        printf("CPU Usage: %.2f%%\n", cpu_usage);
    }

    // 更新前一个值
    prev_idle = idle;
    prev_total = total;

    fclose(fp);
}

void heartbeat() {
   printf("Heartbeat: System is alive!\n");
}

void monitor_cpu_and_send_heartbeat(int tfd) {
   uint64_t expirations;
   int heartbeat_counter = 0;

   while (1) {
       fd_set readfds;
       FD_ZERO(&readfds);
       FD_SET(tfd, &readfds);

       // 等待事件发生
       select(tfd + 1, &readfds, NULL,NULL,NULL);

       if (FD_ISSET(tfd ,&readfds)) {
           read(tfd,&expirations,sizeof(expirations));

           // 每次触发都记录 CPU 占用率，并检查是否需要发送心跳
           record_cpu_usage();
           
           heartbeat_counter++;
           if (heartbeat_counter >= 30) { // 每30秒发送一次心跳
               heartbeat();
               heartbeat_counter = 0; // 重置计数器
           }
       }
   }
}

int main() {
   // 创建定时器文件描述符
   int tfd = timerfd_create(CLOCK_MONOTONIC, 0);
   if (tfd == -1) {
       perror("timerfd_create");
       exit(EXIT_FAILURE);
   }

   struct itimerspec new_value;
   new_value.it_value.tv_sec = 1; 
   new_value.it_value.tv_nsec = 0; 
   new_value.it_interval.tv_sec = 1; 
   new_value.it_interval.tv_nsec = 0; 

   timerfd_settime(tfd, 0, &new_value, NULL);

   monitor_cpu_and_send_heartbeat(tfd); // 调用监测和心跳函数

   close(tfd);
   
return EXIT_SUCCESS;
}

在这个版本中，monitor_cpu_and_send_heartbeat 函数负责监控 CPU 使用情况并发送心跳。主函数现在更简洁，只需设置定时器并调用该新函数即可。这种结构化使得代码更易于理解和维护。

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