poll.c

linuxFedure4环境下串口编程后台运行状态机

//#include "echo.h"

#include <linux/poll.h>
#include <netinet/in.h>
#include <errno.h>
#include <stdlib.h>

#define MAXLINE	10
#define OPEN_MAX	10

int
main( int argc , char * * argv )
{
		int i , j, maxi , listenfd , connfd , sockfd;
		int nready;

		ssize_t n;
		char line[ MAXLINE ];
		int clilen;
		struct pollfd client[ OPEN_MAX ];
		struct sockaddr_in cliaddr , servaddr;

		listenfd = socket( AF_INET , SOCK_STREAM , 0 );
		memset( &servaddr , 0 , sizeof( servaddr ) );
		servaddr.sin_family = AF_INET;
		servaddr.sin_addr.s_addr = htonl( INADDR_ANY );
		servaddr.sin_port = htons( 10000 );

		bind( listenfd , (struct sockaddr *)&servaddr , sizeof( servaddr ) );
		listen( listenfd , 1024 );
		client[0].fd = listenfd;
		client[0].events = POLLRDNORM;
		for( i = 1 ; i < OPEN_MAX ; i ++ )
				client[i].fd = -1;
		maxi = 0; 
		for( ; ; )
		{
				nready = poll( client , maxi + 1 , 100 );
				if( client[0].revents & POLLRDNORM )
				{
						clilen = sizeof( cliaddr );
						connfd = accept( listenfd , (struct sockaddr *)&cliaddr , &clilen );
						
						//write(connfd, "CENTRE|NEW_JOB|1|sword|A|C|CENTRE\0", 255);
						for( i = 1 ; i < OPEN_MAX ; i ++ )
						{
								if( client[i].fd < 0 )
								{
										client[i].fd = connfd;
										break;
								}
						}
						if( i == OPEN_MAX )
						{
								printf( "Too many clients!\n" );
								exit( 1 );
						}
						client[i].events = POLLRDNORM;
						if( i > maxi )
								maxi = i;
						if( -- nready <= 0 )
								continue;
				}
				for( i = 1 ; i <= maxi ; i ++ )
				{
						if( ( sockfd = client[i].fd ) < 0 )
								continue;
						if( client[i].revents & ( POLLRDNORM | POLLERR ) )
						{
								if( ( n = read( sockfd , line , MAXLINE ) ) < 0 )
								{
										if( errno == ECONNRESET )
										{
												close( sockfd );
												client[i].fd = -1;
										}
										else
										{
												printf( "readline error\n" );
												exit( 1 );
										}
								}
								else if( n == 0 )
								{
										close( sockfd );
										client[i].fd = -1;
								}
								else
								{
										for( j = 1; j <= maxi; j++ )	
											if( (sockfd = client[j].fd) > 0 ) write( sockfd , line , n );
								}
								if( -- nready <= 0 )
										break;
						}
				}
		}
}