Function alloc_socket

components/net/lwip/lwip-1.4.1/src/api/sockets.c:254–283

* Allocate a new socket for a given netconn. * * @param newconn the netconn for which to allocate a socket * @param accepted 1 if socket has been created by accept(), * 0 if socket has been created by socket() * @return the index of the new socket; -1 on error */

 * @return the index of the new socket; -1 on error
 */
static int
alloc_socket(struct netconn *newconn, int accepted)
{
  int i;
  SYS_ARCH_DECL_PROTECT(lev);

  /* allocate a new socket identifier */
  for (i = 0; i < NUM_SOCKETS; ++i) {
    /* Protect socket array */
    SYS_ARCH_PROTECT(lev);
    if (!sockets[i].conn) {
      sockets[i].conn       = newconn;
      /* The socket is not yet known to anyone, so no need to protect
         after having marked it as used. */
      SYS_ARCH_UNPROTECT(lev);
      sockets[i].lastdata   = NULL;
      sockets[i].lastoffset = 0;
      sockets[i].rcvevent   = 0;
      /* TCP sendbuf is empty, but the socket is not yet writable until connected
       * (unless it has been created by accept()). */
      sockets[i].sendevent  = (newconn->type == NETCONN_TCP ? (accepted != 0) : 1);
      sockets[i].errevent   = 0;
      sockets[i].err        = 0;
      sockets[i].select_waiting = 0;
      return i;
    }
    SYS_ARCH_UNPROTECT(lev);
  }
  return -1;
}

/** Free a socket. The socket's netconn must have been
 * delete before!