“error: request for member ‘clientfd’ in something not a structure or union”

Question

I get this error when I try to compile my code. I need to pass several arguments to start a thread and I'm having trouble with it. Here are the details I find relevant :

struct args {                                                   
    int clientfd;                                                             
    int serialp;                                                              
};          

struct args threaded;

while(1)
    {
        int clientfd;
        struct sockaddr_in client_addr;
        int addrlen=sizeof(client_addr);

        pthread_t thread1;

        printf("À espera de uma nova ligação...\n");
        clientfd = accept(sock, (struct sockaddr*)&client_addr, &addrlen);

        threaded.clientfd = clientfd;
        threaded.serialp = serialp;

        pthread_create(&thread1, 0, receive_tcp, /*clientfd*/&threaded);       
        pthread_detach(thread1);

    }

void *receive_tcp(void *args)
{
    int buffer1[7];
    int *buffer2;
    int n, i, adress;
    unsigned long int size;
    int clientfd = args.clientfd;

    n = read(clientfd, buffer1, sizeof(buffer1));

    size = 256*buffer1[5]+buffer1[6];

    buffer2 = (int *) malloc (size*sizeof(int));
    n = read(clientfd, buffer2, sizeof(buffer2));

    adress = buffer1[7];

    add_ASCII(buffer2, size, adress, args.serialp);
}

Here's what I getting with the compiling:

Modo1.c:101:21: warning: dereferencing ‘void *’ pointer
  int clientfd = args->clientfd;
                     ^
Modo1.c:101:21: error: request for member ‘clientfd’ in something not a structure or union
Modo1.c:112:39: warning: dereferencing ‘void *’ pointer
  add_ASCII(buffer2, size, adress, args->serialp);
                                       ^
Modo1.c:112:39: error: request for member ‘serialp’ in something not a structure or union

Any idea of what it might be?

Answer 1

void *receive_tcp(void *args)

The type of args is void* . You need to cast it to struct args* before you can access the members of the struct .

void *receive_tcp(void *temp_args)
{
    int buffer1[7];
    int *buffer2;
    int n, i, adress;
    unsigned long int size;

    // Cast the argument
    struct args* real_args = (struct args*)(temp_args);

    // Now access the members
    int clientfd = real_args->clientfd;

    ...