socket

aio.cpp

#include <stdio.h>
#include <stdlib.h>
#include <errno.h>
#include <string.h>
#include <netinet/in.h>
#include <sys/socket.h>
#include <unistd.h>
#include <fcntl.h>
#include <aio.h>
#include <pthread.h>
 
#define BUF_SIZE 1024
 
 
void aio_completion_handler(sigval_t sigval);
 
void setup_io(int fd, aiocb& my_aiocb)
{
  //初始化AIO请求
	bzero( (char *)&my_aiocb, sizeof(struct aiocb) );
	my_aiocb.aio_fildes = fd;
	my_aiocb.aio_buf = malloc(BUF_SIZE+1);
	my_aiocb.aio_nbytes = BUF_SIZE;
	my_aiocb.aio_offset = 0;
	
	//设置线程回调函数
	my_aiocb.aio_sigevent.sigev_notify = SIGEV_THREAD;
	my_aiocb.aio_sigevent.sigev_notify_function = aio_completion_handler;
	my_aiocb.aio_sigevent.sigev_notify_attributes = NULL;
	my_aiocb.aio_sigevent.sigev_value.sival_ptr = &my_aiocb;
}
 
//回调函数
void aio_completion_handler(sigval_t sigval)
{
	struct aiocb *req;
	int ret;
	
	req = (struct aiocb *)sigval.sival_ptr;
	
	if (aio_error(req) == 0) 
	{
		if((ret = aio_return(req)) > 0)
		{
			printf("Thread id %u recv:%s\n", (unsigned int)pthread_self(), (char*)req->aio_buf);
		}
	}
 
	char* buf = (char*)req->aio_buf;
	
	if(send(req->aio_fildes, buf, strlen(buf), 0) == -1)
	{
		perror("send");
		return;
	}
 
	close(req->aio_fildes);
 
	return;
}
 
int main()
{
	int sockfd;
	int sin_size;
	struct sockaddr_in addr, cliaddr;
	
	//创建socket
	if((sockfd = socket(AF_INET, SOCK_STREAM, 0)) < 0)
	{
		perror("createSocket");
		return -1;
	}
	
	//初始化socket结构
	memset(&addr, 0, sizeof(addr));
	addr.sin_family = AF_INET;
	addr.sin_port = htons(7092);
	addr.sin_addr.s_addr = htonl(INADDR_ANY);
	
	//绑定套接口
	if(bind(sockfd,(struct sockaddr *)&addr,sizeof(struct sockaddr))==-1)
	{
		perror("bind");
		return -1;
	}
	
	//创建监听套接口
	if(listen(sockfd,10)==-1)
	{
		perror("listen");
		return -1;
	}
	
	
	printf("server is running!\n");
	
	//等待连接
	while(1) 
	{
		int new_fd;
  		struct aiocb my_aiocb;
		sin_size = sizeof(struct sockaddr_in);
		
		//接受连接
		if((new_fd = accept(sockfd, (struct sockaddr *)&cliaddr, (socklen_t*)&sin_size))==-1)
		{
			perror("accept");
			return -1;
		}
 
		printf("Thread id %u accept connect, fd: %d\n", (unsigned int)pthread_self(), new_fd);
		
		setup_io(new_fd, my_aiocb);
		aio_read(&my_aiocb);
	}
	close(sockfd);
}

BockingIO.cpp

#include <stdio.h>
#include <stdlib.h>
#include <errno.h>
#include <string.h>
#include <netinet/in.h>
#include <sys/socket.h>
#include <unistd.h>
 
int main()
{
  int sockfd, new_fd;
	int sin_size, numbytes;
	struct sockaddr_in addr, cliaddr;
	
	//创建socket
	if((sockfd = socket(AF_INET, SOCK_STREAM, 0)) < 0)
	{
		perror("createSocket");
		return -1;
	}
	
	//初始化socket结构
	memset(&addr, 0, sizeof(addr));
	addr.sin_family = AF_INET;
	addr.sin_port = htons(7092);
	addr.sin_addr.s_addr = htonl(INADDR_ANY);
	
	//绑定套接口
	if(bind(sockfd,(struct sockaddr *)&addr,sizeof(struct sockaddr))==-1)
	{
		perror("bind");
		return -1;
	}
	
	//创建监听套接口
	if(listen(sockfd,10)==-1)
	{
		perror("listen");
		return -1;
	}
	
	
	printf("server is running!\n");
	
	char buff[1024];
	//等待连接
	while(1) 
	{
		sin_size = sizeof(struct sockaddr_in);
		
		//接受连接
		if((new_fd = accept(sockfd, (struct sockaddr *)&cliaddr, (socklen_t*)&sin_size))==-1)
		{
			perror("accept");
			return -1;
		}
		
		//生成一个子进程来完成和客户端的会话，父进程继续监听
		if(!fork())
		{
			//读取客户端发来的信息
			memset(buff,0,sizeof(buff));
			if((numbytes = recv(new_fd,buff,sizeof(buff),0))==-1)
			{
				perror("recv");
				return -1;
			}
			printf("buff=%s\n",buff);
			
			//将从客户端接收到的信息再发回客户端
			if(send(new_fd,buff,strlen(buff),0)==-1)
			{
				perror("send");
			}
	
			close(new_fd);
			return 0;
		}
		//父进程关闭new_fd
		close(new_fd);
	}
	close(sockfd);
}

EventDrivenIO.cpp

#include <sys/socket.h>   
#include <sys/epoll.h>   
#include <netinet/in.h>   
#include <arpa/inet.h>   
#include <fcntl.h>   
#include <unistd.h>   
#include <stdio.h>   
#include <errno.h>   
#include <iostream>   
using namespace std;   

#define MAX_EVENTS 1024 

struct myevent_s   
{   
    int fd;   
    void (*call_back)(int fd, int events, void *arg);   
    int events;   
    void *arg;   
    int status; // 1: in epoll wait list, 0 not in   
    char buff[128]; // recv data buffer  
    int len;  
    long last_active; // last active time   
};   

int g_epollFd;   
myevent_s g_Events[MAX_EVENTS+1]; // g_Events[MAX_EVENTS] is used by listen fd   
void RecvData(int fd, int events, void *arg);   
void SendData(int fd, int events, void *arg);

// set event   
void EventSet(myevent_s *ev, int fd, void (*call_back)(int, int, void*), void *arg)   
{   
    ev->fd = fd;   
    ev->call_back = call_back;   
    ev->events = 0;   
    ev->arg = arg;   
    ev->status = 0;   
    ev->len = 0;
    ev->last_active = time(NULL);   
}   

// add/mod an event to epoll   
void EventAdd(int epollFd, int events, myevent_s *ev)   
{   
    struct epoll_event epv = {0, {0}};   
    int op;   
    epv.data.ptr = ev;   
    epv.events = ev->events = events;   
    if(ev->status == 1){   
        op = EPOLL_CTL_MOD;   
    }   
    else{   
        op = EPOLL_CTL_ADD;   
        ev->status = 1;   
    }   
    if(epoll_ctl(epollFd, op, ev->fd, &epv) < 0)   
        printf("Event Add failed[fd=%d]\n", ev->fd);   
    else  
        printf("Event Add OK[fd=%d]\n", ev->fd);   
}   

// delete an event from epoll   
void EventDel(int epollFd, myevent_s *ev)   
{   
    struct epoll_event epv = {0, {0}};   
    if(ev->status != 1) return;   
    epv.data.ptr = ev;   
    ev->status = 0;   
    epoll_ctl(epollFd, EPOLL_CTL_DEL, ev->fd, &epv);   
}  
    
// accept new connections from clients   
void AcceptConn(int fd, int events, void *arg)   
{   
    struct sockaddr_in sin;   
    socklen_t len = sizeof(struct sockaddr_in);   
    int nfd, i;   
    // accept   
    if((nfd = accept(fd, (struct sockaddr*)&sin, &len)) == -1)   
    {   
        if(errno != EAGAIN && errno != EINTR)   
        {   
            printf("%s: bad accept", __func__);   
        }   
        return;   
    }   
    do  
    {   
        for(i = 0; i < MAX_EVENTS; i++)   
        {   
            if(g_Events[i].status == 0)   
            {   
                break;   
            }   
        }   
        if(i == MAX_EVENTS)   
        {   
            printf("%s:max connection limit[%d].", __func__, MAX_EVENTS);   
            break;   
        }   
        // set nonblocking   
        if(fcntl(nfd, F_SETFL, O_NONBLOCK) < 0) break;   
        // add a read event for receive data   
        EventSet(&g_Events[i], nfd, RecvData, &g_Events[i]);   
        EventAdd(g_epollFd, EPOLLIN|EPOLLET, &g_Events[i]);   
        printf("new conn[%s:%d][time:%d]\n", inet_ntoa(sin.sin_addr), ntohs(sin.sin_port), g_Events[i].last_active);   
    }while(0);   
}   

// receive data   
void RecvData(int fd, int events, void *arg)   
{   
    struct myevent_s *ev = (struct myevent_s*)arg;   
    int len;   
    // receive data   
    len = recv(fd, ev->buff, sizeof(ev->buff)-1, 0);     
    EventDel(g_epollFd, ev);   
    if(len > 0)   
    {   
        ev->len = len;   
        ev->buff[len] = '\0';   
        printf("C[%d]:%s\n", fd, ev->buff);   
        // change to send event   
        EventSet(ev, fd, SendData, ev);   
        EventAdd(g_epollFd, EPOLLOUT|EPOLLET, ev);   
    }   
    else if(len == 0)   
    {   
        close(ev->fd);   
        printf("[fd=%d] closed gracefully.\n", fd);   
    }   
    else  
    {   
        close(ev->fd);   
        printf("recv[fd=%d] error[%d]:%s\n", fd, errno, strerror(errno));   
    }   
}  
 
// send data   
void SendData(int fd, int events, void *arg)   
{   
    struct myevent_s *ev = (struct myevent_s*)arg;   
    int len;  
    
    time_t now = time(0);
  sprintf(ev->buff, "Server Time is : %s", ctime(&now)); 
    // send data   
    len = send(fd, ev->buff, strlen(ev->buff), 0);   
    ev->len = 0;   
    EventDel(g_epollFd, ev);   
    if(len > 0)   
    {   
        // change to receive event   
        EventSet(ev, fd, RecvData, ev);   
        EventAdd(g_epollFd, EPOLLIN|EPOLLET, ev);   
    }   
    else  
    {   
        close(ev->fd);   
        printf("recv[fd=%d] error[%d]\n", fd, errno);   
    }   
}   
void InitListenSocket(int epollFd, short port)   
{   
    int listenFd = socket(AF_INET, SOCK_STREAM, 0);   
    fcntl(listenFd, F_SETFL, O_NONBLOCK); // set non-blocking   
    printf("server listen fd=%d\n", listenFd);   
    EventSet(&g_Events[MAX_EVENTS], listenFd, AcceptConn, &g_Events[MAX_EVENTS]);   
    // add listen socket   
    EventAdd(epollFd, EPOLLIN|EPOLLET, &g_Events[MAX_EVENTS]);   
    // bind & listen   
    sockaddr_in sin;   
    bzero(&sin, sizeof(sin));   
    sin.sin_family = AF_INET;   
    sin.sin_addr.s_addr = INADDR_ANY;   
    sin.sin_port = htons(port);   
    bind(listenFd, (const sockaddr*)&sin, sizeof(sin));   
    listen(listenFd, 5);   
}   

int main(int argc, char **argv)   
{   
    short port = 7092; // default port   
    
    // create epoll   
    g_epollFd = epoll_create(MAX_EVENTS);   
    if(g_epollFd <= 0) printf("create epoll failed.%d\n", g_epollFd);   
    	
    // create & bind listen socket, and add to epoll, set non-blocking   
    InitListenSocket(g_epollFd, port);  
     
    // event loop   
    struct epoll_event events[MAX_EVENTS];   
    printf("server running:port[%d]\n", port); 
      
    int checkPos = 0;   
    while(1){   
        // a simple timeout check here, every time 100, better to use a mini-heap, and add timer event   
        long now = time(NULL);   
        for(int i = 0; i < 100; i++, checkPos++) // doesn't check listen fd   
        {   
            if(checkPos == MAX_EVENTS) checkPos = 0; // recycle   
            if(g_Events[checkPos].status != 1) continue;   
            long duration = now - g_Events[checkPos].last_active;   
            if(duration >= 60) // 60s timeout   
            {   
                close(g_Events[checkPos].fd);   
                printf("[fd=%d] timeout[%d--%d].\n", g_Events[checkPos].fd, g_Events[checkPos].last_active, now);   
                EventDel(g_epollFd, &g_Events[checkPos]);   
            }   
        }   
        // wait for events to happen   
        int fds = epoll_wait(g_epollFd, events, MAX_EVENTS, 1000);   
        if(fds < 0){   
            printf("epoll_wait error, exit\n");   
            break;   
        }   
        for(int i = 0; i < fds; i++){   
            myevent_s *ev = (struct myevent_s*)events[i].data.ptr;   
            if((events[i].events&EPOLLIN)&&(ev->events&EPOLLIN)) // read event   
            {   
                ev->call_back(ev->fd, events[i].events, ev->arg);   
            }   
            if((events[i].events&EPOLLOUT)&&(ev->events&EPOLLOUT)) // write event   
            {   
                ev->call_back(ev->fd, events[i].events, ev->arg);   
            }   
        }   
    }   
    // free resource   
    return 0;   
}   

IOMutiPlexing.cpp

#include <stdio.h>
#include <stdlib.h>
#include <errno.h>
#include <string.h>
#include <netinet/in.h>
#include <sys/socket.h>
#include <unistd.h>
#include <fcntl.h>
#include <netdb.h>
#include <sys/epoll.h>
 
#define MAXEVENT 1024
 
int create_server_socket(int& sockfd)
{
  struct sockaddr_in addr;
	
	//创建socket
	if((sockfd = socket(AF_INET, SOCK_STREAM, 0)) < 0)
	{
		perror("createSocket");
		return -1;
	}
	
	//初始化socket结构
	memset(&addr, 0, sizeof(addr));
	addr.sin_family = AF_INET;
	addr.sin_port = htons(7092);
	addr.sin_addr.s_addr = htonl(INADDR_ANY);
	
	//绑定套接口
	if(bind(sockfd,(struct sockaddr *)&addr,sizeof(struct sockaddr))==-1)
	{
		perror("bind");
		return -1;
	}
	
	//创建监听套接口
	if(listen(sockfd,10)==-1)
	{
		perror("listen");
		return -1;
	}
	
	return 0;	
}
 
int set_socket_non_blocking(int fd)
{
	int flags, s;
	
	flags = fcntl (fd, F_GETFL, 0);
	if (flags == -1)
	{
		perror ("fcntl F_GETFL failed");
		return -1;
	}
	
	flags |= O_NONBLOCK;
	s = fcntl (fd, F_SETFL, flags);
	if (s == -1)
	{
		perror ("fcntl F_SETFL failed");
		return -1;
	}
	
	return 0;
}
 
int main()
{
	int sockfd, efd;
	struct epoll_event event;
	struct epoll_event *events;	
	int s;
	
	if(create_server_socket(sockfd) != 0)
	{
		perror("create server sock failed\n");
		return 1;
	}
	set_socket_non_blocking(sockfd);
	
	printf("server is running!\n");
 
	//创建一个epoll的句柄
	//int epoll_create(int size)  
	//Since Linux 2.6.8, the size argument is unused. (The kernel dynamically sizes the required data structures without needing this initial hint.)
	efd = epoll_create(MAXEVENT);
	if (efd == -1)
	{
		perror ("epoll_create");
		abort ();
	}
 
	//注册新事件到epoll efd
	event.data.fd = sockfd;
	event.events = EPOLLIN | EPOLLET;
	s = epoll_ctl(efd, EPOLL_CTL_ADD, sockfd, &event);
	if (s == -1)
	{
		perror ("epoll_ctl EPOLL_CTL_ADD failed");
		abort ();
	}
	
	events = (epoll_event*)calloc(MAXEVENT, sizeof(event));
	
	while (1)
    {
		int n, i;
		n = epoll_wait(efd, events, MAXEVENT, -1);
		for (i = 0; i < n; i++)
    	{
    		//fd error
      		if ((events[i].events & EPOLLERR) ||
              	(events[i].events & EPOLLHUP) ||
              (!(events[i].events & EPOLLIN)))
        	{
				perror("epoll error\n");
				close (events[i].data.fd);
				continue;
			}
			//新连接
      		else if (sockfd == events[i].data.fd)
       		{
				while (1)
				{
					struct sockaddr in_addr;
					socklen_t in_len;
					int infd;
					char hbuf[NI_MAXHOST], sbuf[NI_MAXSERV];
					
					//接受连接
					in_len = sizeof(in_addr);
					infd = accept(sockfd, &in_addr, &in_len);
					if (infd == -1)
					{
						if ((errno == EAGAIN) ||
						  (errno == EWOULDBLOCK))
						{
							//已接受所有连接
					      	break;
					    }
						else
						{
							perror ("accept");
							break;
						}
					}
					
					s = getnameinfo (&in_addr, in_len,
					               hbuf, sizeof hbuf,
					               sbuf, sizeof sbuf,
					               NI_NUMERICHOST | NI_NUMERICSERV);
					if (s == 0)
					{
					  printf("Accepted connection on descriptor %d "
					         "(host=%s, port=%s)\n", infd, hbuf, sbuf);
					}
					
					/* 设置新接受的socket连接无阻塞*/
					s = set_socket_non_blocking (infd);
					if (s == -1)
					{
					return 1;
					}
					
					//注册新事件到epoll
					event.data.fd = infd;
					event.events = EPOLLIN | EPOLLET;
					s = epoll_ctl(efd, EPOLL_CTL_ADD, infd, &event);
					if (s == -1)
					{
					  perror ("epoll_ctl");
					  return 1;
					}
				}
				continue;
            }
            //数据可读
          	else
            {
              int done = 0;
              while (1)
              {
                  ssize_t count;
                  char buf[512];
                  count = read(events[i].data.fd, buf, sizeof(buf));
                  if(count == -1)
                  {
                      //数据读完
                      if (errno != EAGAIN)
                      {
                          perror ("read");
                          done = 1;
                      }
                      break;
                  }
                  else if(count == 0)
                  {
                      /* End of file. The remote has closed the
                         connection. */
                      done = 1;
                      break;
                   }
 
                  printf("recv: %s\n", buf);
                }
 
              if (done)
              {
                  printf ("Closed connection on descriptor %d\n", events[i].data.fd);
                  close (events[i].data.fd);
              }
            }
        }
    }
 
  free (events);
  close(sockfd);
  return 0;
}

NoBlockingIO.cpp

#include <stdio.h>
#include <stdlib.h>
#include <errno.h>
#include <string.h>
#include <netinet/in.h>
#include <sys/socket.h>
#include <unistd.h>
#include <fcntl.h>
 
int main()
{
  int sockfd, new_fd;
	int sin_size;
	struct sockaddr_in addr, cliaddr;
	
	//创建socket
	if((sockfd = socket(AF_INET, SOCK_STREAM, 0)) < 0)
	{
		perror("createSocket");
		return -1;
	}
	
	//初始化socket结构
	memset(&addr, 0, sizeof(addr));
	addr.sin_family = AF_INET;
	addr.sin_port = htons(7092);
	addr.sin_addr.s_addr = htonl(INADDR_ANY);
	
	//绑定套接口
	if(bind(sockfd,(struct sockaddr *)&addr,sizeof(struct sockaddr))==-1)
	{
		perror("bind");
		return -1;
	}
	
	//创建监听套接口
	if(listen(sockfd,10)==-1)
	{
		perror("listen");
		return -1;
	}
	
	
	printf("server is running!\n");
	
	char buff[1024];
	//等待连接
	while(1) 
	{
		sin_size = sizeof(struct sockaddr_in);
		
		//接受连接
		if((new_fd = accept(sockfd, (struct sockaddr *)&cliaddr, (socklen_t*)&sin_size))==-1)
		{
			perror("accept");
			return -1;
		}
			
		//生成一个子进程来完成和客户端的会话，父进程继续监听
		if(!fork())
		{
			//设置new_fd无阻塞属性
			int flags;
			if((flags=fcntl(new_fd, F_GETFL, 0))<0)  
            {
            	perror("fcntl F_GETFL");  
            }
    	    flags |= O_NONBLOCK;  
      		if(fcntl(new_fd, F_SETFL,flags)<0)  
            {
            	perror("fcntl F_SETFL");  
			}
			
			//读取客户端发来的信息
			memset(buff,0,sizeof(buff));
			while(1)
			{
				if((recv(new_fd,buff,sizeof(buff),0)) < 0)
				{
					if(errno==EWOULDBLOCK)
					{
						perror("recv error, wait....");
						sleep(1);
						continue;
					}
				}
				else
				{
					printf("buff=%s\n",buff);
				}	
				break;
			}
 
			//发送数据
			while(1)
			{
				if(send(new_fd,buff,strlen(buff),0) < 0)
				{
					if(errno==EWOULDBLOCK)
					{
						perror("send error, wait....");
						sleep(1);
						continue;
					}
				}
				else
				{
					printf("buff=%s\n",buff);
				}	
				break;
			}
	
			close(new_fd);
			return 0;
		}
		//父进程关闭new_fd
		close(new_fd);
	}
	close(sockfd);
}

SocketClientUnix.cpp

#include <stdio.h>
#include <stdlib.h>
#include <errno.h>
#include <string.h>
#include <netdb.h>
#include <sys/types.h>
#include <netinet/in.h>
#include <sys/socket.h>
#include <unistd.h>
 
int main(int argc,char *argv[])
{
  if(argc!=3)
	{
		printf("%s: input IP & port\n",argv[0]);
		return 1;
	}
	int sockfd,numbytes;
	char buf[100] = "hello world";
	struct hostent *he;
	struct sockaddr_in their_addr;
	
	//将基本名字和地址转换
	he = gethostbyname(argv[1]);
	
	//建立一个TCP套接口
	if((sockfd = socket(AF_INET,SOCK_STREAM,0))==-1)
	{
		perror("socket");
		exit(1);
	}
	
	//初始化结构体，连接到服务器的2323端口
	their_addr.sin_family = AF_INET;
	their_addr.sin_port = htons(atoi(argv[2]));
	their_addr.sin_addr = *((struct in_addr *)he->h_addr);
	bzero(&(their_addr.sin_zero),8);
	
	//和服务器建立连接
	if(connect(sockfd,(struct sockaddr *)&their_addr,sizeof(struct sockaddr))==-1)
	{
		perror("connect");
		exit(1);
	}
	
	//向服务器发送字符串
	if(send(sockfd,buf,strlen(buf),0)==-1)
	{
		perror("send");
		exit(1);
	}
	memset(buf,0,sizeof(buf));
	
	//接受从服务器返回的信息
	if((numbytes = recv(sockfd,buf,100,0))==-1)
	{
		perror("recv");
		exit(1);
	}
	
	close(sockfd);
	return 0;
}