RE: [lwip-devel] [bug #20021] conn->sem is only signaled one-way

[Goldschmidt Simon]

OK for me!

> Follow-up Comment #22, bug #20021 (project lwip):
> 
> About socket layer: so, netconn_close is not called, we stay on a
> netconn_delete: ok, since this call do the job (and a smart 
> linker will remove netconn_close/do_close from the code).
> 
> I see a little problem: netconn_delete is called inside the 
> sys_sem_wait(socksem)/sys_sem_signal(socksem).
> 
> I think it could be a problem because any new socket can't be 
> created during the close. Comments in lwip_close say it's 
> done because "/* We cannot allow multiple closes of the same 
> socket. */". Since others API file like lwip_send can call by 
> another thread in the same time, I think this protection is 
> not enough, and give more problem.
> 
> I propose to change the code like this :
> 
> int
> lwip_close(int s)
> {
>   struct lwip_socket *sock;
> 
>   LWIP_DEBUGF(SOCKETS_DEBUG, ("lwip_close(%d)n", s));
> 
>   sock = get_socket(s);
>   if (!sock) {
>     return -1;
>   }
> 
>   netconn_delete(sock->conn);
> 
>   sys_sem_wait(socksem);
>   if (sock->lastdata) {
>     netbuf_delete(sock->lastdata);
>   }
>   sock->lastdata   = NULL;
>   sock->lastoffset = 0;
>   sock->conn       = NULL;
>   sock_set_errno(sock, 0);
>   sys_sem_signal(socksem);
>   return 0;
> }
> 
> Comments?