linux select I/O共享服务端

花了两天时间，终于写好了一个select I/O复用服务端，真不容易，拿出来和大伙分享一下，O(∩_∩)O~

/******************************************************************************  Copyright (C), 2001-2011, DCN Co., Ltd. ******************************************************************************  File Name     : main.c  Version       : Initial Draft  Author        : Dong Shen  Created       : 2012/9/19  Last Modified :  Description   : transcode main******************************************************************************/#include <stdio.h>#include <stdlib.h>#include <unistd.h>#include <errno.h>#include <string.h>#include <sys/types.h>#include <sys/socket.h>#include <netinet/in.h>#include <arpa/inet.h>#include <sys/queue.h>#include <m_type.h>#define MYPORT          1234    // the port users will be connecting to#define BACKLOG         512     // how many pending connections queue will hold#define BUF_SIZE        1024#define MAX_PATH_LEN    255#ifndef bool    #define bool int#endif#define FALSE 0#define TRUE  1typedef enum media_handle_e{    E_NONE      = 0,    E_PARSER    = 1,    E_TRANSCODE = 2}media_handle_e;typedef enum platform_e{    E_PF_NONE   = 0,    E_PF_PC     = 1,    E_PF_PAD    = 2,    E_PF_PHONE  = 3}platform_e;typedef struct fd_a_t{    int     fd_a;        bool    need_write;    media_handle_e handle_type;    char path[MAX_PATH_LEN];    char out_path[MAX_PATH_LEN];    SO_Format_Type fmt_type;    SO_Codec_ID v_codec;    SO_Codec_ID a_codec;    int * bitrate;    int bitrate_count;    int width;    int height;    char * plat_form;        char *  ret_buf;    int     ret_buf_len;    TAILQ_ENTRY(fd_a_t) fd_a_node;}fd_a_t;typedef  TAILQ_HEAD(fd_a_list_t_, fd_a_t) fd_a_list_t;int main(void){        int ret     = 0;    int sock_fd = 0; // listen on sock_fd    int new_fd  = 0; // new connection on new_fd    struct sockaddr_in server_addr; // server address information    struct sockaddr_in client_addr; // connector's address information    memset(&server_addr, 0, sizeof(struct sockaddr_in));    memset(&client_addr, 0, sizeof(struct sockaddr_in));        sock_fd = socket(AF_INET, SOCK_STREAM, 0);    if (-1 == sock_fd)     {        perror("socket");        return -1;    }      int yes = 1;      ret = setsockopt(sock_fd, SOL_SOCKET, SO_REUSEADDR, &yes, sizeof(int));      if (-1 == ret)       {          perror("setsockopt");          return -1;      }      server_addr.sin_family      = AF_INET;              // host byte order    server_addr.sin_port        = htons(MYPORT);        // short, network byte order    server_addr.sin_addr.s_addr = INADDR_ANY;           // automatically fill with my IP    memset(server_addr.sin_zero, '\0', sizeof(server_addr.sin_zero));    ret = bind(sock_fd, (struct sockaddr *)&server_addr, sizeof(server_addr));    if (-1 == ret)     {        perror("bind");        return -1;    }    ret = listen(sock_fd, BACKLOG);    if (-1 == ret)    {        perror("listen");        return -1;    }    int maxsock     = 0;    int conn_amount = 0;    fd_a_list_t  fd_a_hd;    TAILQ_INIT(&fd_a_hd);        fd_set read_fdsr;    fd_set write_fdsr;             // timeout setting        // struct timeval tv;                while (1)     {        // tv.tv_sec = 30;        // tv.tv_usec = 0;                // initialize file descriptor set            FD_ZERO(&read_fdsr);        FD_ZERO(&write_fdsr);        FD_SET(sock_fd, &read_fdsr);        // FD_SET(sock_fd, &write_fdsr);        maxsock = sock_fd;        fd_a_t * cur_fd_node = TAILQ_FIRST(&fd_a_hd);        while (cur_fd_node != NULL)        {            FD_SET(cur_fd_node->fd_a, &read_fdsr);            FD_SET(cur_fd_node->fd_a, &write_fdsr);            if (cur_fd_node->fd_a > maxsock)            {                maxsock = cur_fd_node->fd_a;            }            cur_fd_node = TAILQ_NEXT(cur_fd_node, fd_a_node);                    }        // select read write socket fd, read_fdsr.        ret = select(maxsock + 1, &read_fdsr, &write_fdsr, NULL, NULL);        if (ret < 0)         {            perror("select");            break;        }         else if (ret == 0)         {            printf("select timeout\n");            continue;        }                // check whether a new connection comes        if (FD_ISSET(sock_fd, &read_fdsr))         {            int sin_size = sizeof(client_addr);            new_fd = accept(sock_fd, (struct sockaddr *)&client_addr, &sin_size);            if (new_fd <= 0)             {                perror("accept");                continue;            }            // add to fd queue            if (conn_amount < BACKLOG)             {                // create new fd node, insert into fd list                fd_a_t * new_fd_a_node  = calloc(1, sizeof(fd_a_t));                new_fd_a_node->fd_a     = new_fd;                TAILQ_INSERT_TAIL(&fd_a_hd, new_fd_a_node, fd_a_node);                conn_amount++;                                printf("new connection client[%d] %s:%d\n", new_fd, inet_ntoa(client_addr.sin_addr), ntohs(client_addr.sin_port));                    }            else             {                printf("max connections arrive, exit\n");                send(new_fd, "bye", 4, 0);                close(new_fd);                continue;            }        }        // check every fd in the set        cur_fd_node = TAILQ_FIRST(&fd_a_hd);        while(cur_fd_node != NULL)        {            if (FD_ISSET(cur_fd_node->fd_a, &read_fdsr))            {                char recv_buf[BUF_SIZE] = {0};                int ret_len = recv(cur_fd_node->fd_a, recv_buf, sizeof(recv_buf), 0);                if (ret_len <= 0) // client close                {                            printf("client[%d] close\n", cur_fd_node->fd_a);                                              // close socket, clear fd_set                    close(cur_fd_node->fd_a);                                        // remove fd_node from fd_list                    fd_a_t * next_fd_node = TAILQ_NEXT(cur_fd_node, fd_a_node);                    TAILQ_REMOVE(&fd_a_hd, cur_fd_node, fd_a_node);                    free_node(cur_fd_node);                                        cur_fd_node = next_fd_node;                    conn_amount--;                    continue;                }                 else // receive data                {                            printf("revice client[%d] msg:%s\n", cur_fd_node->fd_a, recv_buf);                    str_parser(recv_buf, ret_len, cur_fd_node);                    if (E_PARSER == cur_fd_node->handle_type)                    {                        media_parser(cur_fd_node);                    }                    else if (E_TRANSCODE == cur_fd_node->handle_type)                    {                        media_transcode(cur_fd_node);                    }                    else                    {                        ;                    }                    cur_fd_node->need_write = TRUE;                                                        }            }            if (FD_ISSET(cur_fd_node->fd_a, &write_fdsr))            {                if (TRUE == cur_fd_node->need_write)                {                                printf("server send msg %s, len %d\n", cur_fd_node->ret_buf, cur_fd_node->ret_buf_len);                    send(cur_fd_node->fd_a, cur_fd_node->ret_buf, cur_fd_node->ret_buf_len, 0);                    cur_fd_node->need_write = FALSE;                }            }            cur_fd_node = TAILQ_NEXT(cur_fd_node, fd_a_node);        }       }    fd_a_t * cur_fd_node = NULL;    while ((cur_fd_node = TAILQ_FIRST(&fd_a_hd)) != NULL)    {        printf("client[%d] close\n", cur_fd_node->fd_a);                // close socket, clear fd_set        close(cur_fd_node->fd_a);                // remove fd_node from fd_list        TAILQ_REMOVE(&fd_a_hd, cur_fd_node, fd_a_node);        free_node(cur_fd_node);                conn_amount--;            }        return 1;}