select多socket写法

发现网络上较难找多select 多socket的事例。

谢了一个供参考接收端：#include<sys/select.h>#include<sys/types.h>#include<sys/socket.h>#include<netinet/in.h>#include<unistd.h>#include<pthread.h>#include<stdio.h>#include<string.h>#define MY_MAX(a,b) (a)>(b)?(a):(b)typedef struct{int soc_count;pthread_t tid;fd_set fdset;int exit_flag;int socket_set[32];struct sockaddr_in addr[32];pthread_mutex_t mutex_lock;}UDP_SERVER_CTRL_T;UDP_SERVER_CTRL_T server_ctrl;void * run_thread(void *arg){int i,len;int max_fd = -1;struct sockaddr_in*tmp_sockaddr;struct timeval time_out = {1,0};unsigned char message_buf[1024];int active_socket_count;int addr_len = sizeof(struct sockaddr_in);while(1){FD_ZERO(&server_ctrl.fdset);for (i = 0; i < sizeof(server_ctrl.socket_set)/sizeof(int); i++){max_fd = MY_MAX(server_ctrl.socket_set[i], max_fd);if (server_ctrl.socket_set[i] > 0){FD_SET(server_ctrl.socket_set[i], &server_ctrl.fdset);//printf("check the port socket %d / %d \n",server_ctrl.socket_set[i], ntohs(server_ctrl.addr[i].sin_port));}}time__sec = 10;time__usec = 0;active_socket_count = select(max_fd + 1, &server_ctrl.fdset, NULL,NULL ,&time_out);switch (active_socket_count){case 0:printf("waiting socket time out\n");break;case -1:printf("select error\n");break;default:memset(message_buf, 0 , sizeof(message_buf));for (i = 0; i < sizeof(server_ctrl.socket_set)/sizeof(int); i++) {if (server_ctrl.socket_set[i] < 0){continue;}if( FD_ISSET(server_ctrl.socket_set[i], &server_ctrl.fdset)) {tmp_sockaddr = &server_ctrl.addr[i];len = recvfrom(server_ctrl.socket_set[i],message_buf,sizeof(message_buf), 0, (struct sockaddr *)tmp_sockaddr,&addr_len);message_buf[len] = '\n';printf("recv message: %s \n", message_buf);}}if (i >= sizeof(server_ctrl.socket_set)){printf("fuck error message\n");break;}}if (server_ctrl.exit_flag){printf("run thread exit\n");break;}}return 0;}int create_task(void){int retval = 0;int socket_fd;struct sockaddr_in *sock_addr_p = NULL;int input_port;int port = 0;char c;int i;/*****************************************/int len = 0;unsigned char message_buf[1024];int addr_len = sizeof(struct sockaddr_in);/*****************************************/printf("----------------------------------------------------------\n"); printf("press a create a socket\n");printf("press b del a socket\n");printf("press c exit \n");printf("\n");printf("\n");printf("----------------------------------------------------------\n");c = getchar();input_port = 0;switch(c){case'a':printf("input port\n");scanf("%d", &input_port);for (i = 0; i < sizeof(server_ctrl.socket_set)/sizeof(int); i++){if (server_ctrl.socket_set[i] == -1){sock_addr_p = &server_ctrl.addr[i];break;}}if (i >= sizeof(server_ctrl.socket_set)){printf(" error %d\n",__LINE__);return -1;}bzero(sock_addr_p, sizeof(struct sockaddr_in));sock_addr_p->sin_family = AF_INET;sock_addr_p->sin_addr.s_addr = htonl(INADDR_ANY);sock_addr_p->sin_port = htons(input_port);socket_fd = socket(AF_INET, SOCK_DGRAM, 0);if (socket_fd < 0){printf("create socket fail\n");return -1;}retval = bind(socket_fd, (struct sockaddr *)sock_addr_p,sizeof(struct sockaddr_in));if (retval){printf("bind socket fail\n");close(socket_fd);}if (server_ctrl.socket_set[i] == -1){pthread_mutex_lock(&server_ctrl.mutex_lock);FD_SET(socket_fd, &server_ctrl.fdset);server_ctrl.socket_set[i] = socket_fd;memcpy(&server_ctrl.addr[i], sock_addr_p, sizeof(struct sockaddr_in));pthread_mutex_unlock(&server_ctrl.mutex_lock);}break;case'b':pthread_mutex_lock(&server_ctrl.mutex_lock );for (i = 0; i < sizeof(server_ctrl.socket_set)/sizeof(int); i++) {if (server_ctrl.socket_set[i] > 0){close(server_ctrl.socket_set[i]);FD_CLR(server_ctrl.socket_set[i], &server_ctrl.fdset); server_ctrl.socket_set[i] = -1;break;}}pthread_mutex_unlock(&server_ctrl.mutex_lock );break;case'c':server_ctrl.exit_flag = 1;return 0;}return -1;}int main(int argc, char **argv){int i;int retval = 0;for (i = 0; i < sizeof(server_ctrl.socket_set)/sizeof(int); i++) {server_ctrl.socket_set[i] = -1;}FD_ZERO(&server_ctrl.fdset);pthread_mutex_init(&server_ctrl.mutex_lock ,NULL);pthread_create(&(server_ctrl.tid), NULL, run_thread,NULL);server_ctrl.exit_flag = 0;printf("stupid sizie %d\n", sizeof(server_ctrl.socket_set));while(1){retval = create_task();if (retval == 0){printf("main thread exit\n");break;}}pthread_join(server_ctrl.tid, NULL);pthread_mutex_destroy(&server_ctrl.mutex_lock);return 0;}发送端：#include<stdio.h>#include<stdlib.h>#include<string.h>#include<sys/socket.h>#include<netinet/in.h>#include<arpa/inet.h>#include<netdb.h>#define PACKET_COUNT 1000int main(int agrc, char *argv[]){int time_counter = PACKET_COUNT;int socket_fd = -1;char *port_char = argv[1];if (argv[1] == NULL){printf(" input port id\n");return 0;}char meg_buff[512] = {"Hello I am the client"};const int port = atoi(port_char);struct sockaddr_in addr_dst;addr_dst.sin_family = AF_INET;addr_dst.sin_port = htons(port);addr_dst.sin_addr.s_addr = inet_addr("10.2.2.73");socket_fd = socket(AF_INET, SOCK_DGRAM, 0);if (socket_fd < 0){printf("create a socket fail\n");return -1;}while ( 0 < time_counter--){printf("sent %4dth packet port %d\n",PACKET_COUNT - time_counter, port);sprintf(meg_buff,"Hello I am the client %spacket %d\n",argv[1] ,PACKET_COUNT - time_counter);sendto(socket_fd, meg_buff, strlen(meg_buff) + 1,0 , (struct sockaddr*)&(addr_dst), sizeof(addr_dst)); sleep(10);}close(socket_fd);return 0;}代码已经编译通过，压力测试没有问题。