linux实现基础网络库（socket,epoll,pthread,cmake,pipe, sem,codition,）

面试时经常会问到网络库，好久没看过这块知识了，实现一下，用到了一下一些知识点

1. socket搭建网络库必须用到的
2. epoll 多路复用技术用的是epoll
3. pthread 服务器用到了多线程，主线程启动服务器，子线程处理来自各个连接的数据
4. pipe 用在进程间通讯 0是读 1是写
5. sem 信号 用在进程间通讯
6. pthread_con_t 条件变量，用于进程间通讯
7. cmake 用来编译工程

下面是服务器代码：epollserver.cpp

#include<stdio.h>
#include<iostream>
#include<cstring>
#include<sys/socket.h>
#include<netinet/in.h>
#include<arpa/inet.h>
#include<unistd.h>
#include<fcntl.h>
#include<sys/epoll.h>
#include<errno.h>
#include<pthread.h>
#include <semaphore.h>

using namespace std;
typedef struct sockaddr_in sockaddr_in;

sem_t sem;	// 信号
pthread_cond_t cond; // 条件变量
pthread_mutex_t mutex; // 互斥锁

int pipeHandle[2];	// 管道 0读端， 1写端

void set_non_blocking(int sock)
{
	int flag;
	flag = fcntl(sock, F_GETFL);
	if (flag < 0) {
		cout << "error fcntl(sock, GETFL)! " << endl;
		return;
	}

	flag |= O_NONBLOCK;
	if (fcntl(sock, F_SETFL, flag) < 0) {
		cout << "error fcntl(sock, F_SETFL, opts)! " << endl;
		return;
	}
}

void* voteAction(void* data) {
	while (1)
	{
		pthread_cond_wait(&cond, &mutex);				// 无条件等待，与互斥锁配合防止多个线程同时调用
		pthread_t senderId;
		read(pipeHandle[0], &senderId, sizeof(senderId));
		cout << "vote action: people " << senderId << " vote action happen, please call 110" << endl;
		write(pipeHandle[1], &senderId, sizeof(senderId));
		sem_post(&sem);
	}
	return NULL;
}

void* policeCenter(void* data)
{
	while (1) {
		sem_wait(&sem);
		pthread_t senderId;
		read(pipeHandle[0], &senderId, sizeof(senderId));
		cout << "110 center recevice people" << senderId << " notify vote event happened" << endl;
	}
	return NULL;
}


struct my_params {
	int