2

I keep getting a "Accept: too many files" error after running my server.c code. Trying to get it to create new threads for clients and limit connections with semaphores.

This is my code:

#define MAX_CLIENTS 30
sem_t s;

void *handle(void *pnewsock);

int sockfd, new_fd, numbytes;  // listen on sock_fd, new connection on new_fd
    struct sockaddr_in my_addr;    // my address information
    struct sockaddr_in their_addr; // connector's address information
    socklen_t sin_size;
    pthread_t thread;

int main(void){
    //initialise locks
    sem_init(&s, 0, 0);

    /* generate the socket */
    if ((sockfd = socket(AF_INET, SOCK_STREAM, 0)) == -1) {
            perror("socket");
            exit(true);
    }

    my_addr.sin_family = AF_INET;         // host byte order
    my_addr.sin_port = htons(MYPORT);     // short, network byte order
    my_addr.sin_addr.s_addr = INADDR_ANY; // auto-fill with my IP

    /* bind the socket to the end point */
    if (bind(sockfd, (struct sockaddr *)&my_addr, sizeof(struct sockaddr)) \
    == -1) {
            perror("bind");
            exit(true);
    }

    /* start listnening */
    if (listen(sockfd, BACKLOG) == -1) {
            perror("listen");
            exit(true);
    }
    printf("server starts listening ...\n");

    /* Main loop */
    while (1) {
            sin_size = sizeof(struct sockaddr_in);
            if (pthread_create(&thread, NULL, handle, &new_fd) != 0) {
                    fprintf(stderr, "Failed to create thread\n");
            }
    }
    return 0;
}

void *handle(void *pnewsock){
    int value;
    sem_getvalue(&s,&value);
    while (value >= MAX_CLIENTS){
            printf("too many connections");
            sem_wait(&s);
    }
    if (value < MAX_CLIENTS){
            if ((new_fd = accept(sockfd, (struct sockaddr *)&their_addr, \
                    &sin_size)) == -1) {
                    perror("accept");
                    exit(1);
            }
            printf("server: got connection from %s\n", \
                    inet_ntoa(their_addr.sin_addr));

            char buffer[MAXDATASIZE];
            char res[MAXDATASIZE];

            memset(buffer, '\0', MAXDATASIZE);
            memset(res, '\0', sizeof(res));

            if ((numbytes=recv(new_fd, buffer, sizeof(buffer), 0)) == -1) {
                    perror("recv");
                    exit(true);
            }
            else if(numbytes == 0) {
                    printf("client left");
                    sem_post(&s);
                    close(new_fd);
                    exit(false);
            }
            else {
                    buffer[numbytes] = '\0'; // add null terminator
                    printf("Request: %s\n",buffer);
                    //search function
            }
    }
    close(new_fd);
    exit(false);
    return NULL;

}

Can anyone give me some insight to this file leak? Thanks

4

1 回答 1

0

main() 函数使用无限循环创建 pthread。您的错误很可能与此有关，因为循环将继续创建更新的线程。

/* Main loop */
while (1) {
        sin_size = sizeof(struct sockaddr_in);
        if (pthread_create(&thread, NULL, handle, &new_fd) != 0) {
                fprintf(stderr, "Failed to create thread\n");
        }
}

您可能的意思是为每个客户端创建一个线程。如果是这种情况，那么当它从 accept() 调用中获得新客户端时，handle() 函数应该调用 pthread_create()。服务器（我们称之为监听和接受的套接字）不需要多个线程——一个线程——可以是主线程——它只需要一个线程。

于 2013-10-18T04:47:48.030 回答