Re: FD_SETSIZE with large #s of files/ports in use

Hi,

Could you please try the attached patch?

regards,
Hiroshi Inoue

Barry Nicholson wrote:
> An interesting issue came up the other day.  We are working with an
> application that opens a considerable number of files and tcp/udp ports
> (>3000).   Unfortunately, that means that the odbc driver fails
> sometimes due to a corrupted stack.  We eventually figured out what was
> causing the corrupted stack.
>
> The SOCK_wait_for_ready(SocketClass *sock, BOOL output, int retry_count)
> function inside socket.c calls select.  Unfortunately, the socket file
> descriptor number can be quite large at this time.  That means that the
> fd_set fds variable can misused.   The fd_set variable type only allows
> 1024 file descriptors to be used by the calling program on many Linux
> versions.   This can be changed by setting FD_SETSIZE or __FD_SETSIZE to
> a larger number.   We have ran tests where we were able to change the
> __FD_SETSIZE value in
> /usr/src/...linuxversion../linux/include/linux/posix_types.h.   The fix
> worked well.
>
> Unfortunately, this isn't a good solution because a software update to
> another linux version will invalidate our fix.   We've tried various
> mechanisms to set FD_SETSIZE or __FD_SETSIZE in socket.c but with no
> luck.   Has anyone else had this problem and came up with a good fix?
> Or is there a better solution?
>
> Barry Nicholson
> Niceng.com
*** socket.c.orig    2010-02-04 00:40:55.643000000 +0900
--- socket.c    2010-05-19 08:53:59.429000000 +0900
***************
*** 385,391 ****
              FD_ZERO(&except_fds);
              FD_SET(self->socket, &fds);
              FD_SET(self->socket, &except_fds);
!             ret = select((int) self->socket + 1, NULL, &fds, &except_fds, timeout > 0 ? &tm : NULL);
              gerrno = SOCK_ERRNO;
              if (0 < ret)
                  break;
--- 385,391 ----
              FD_ZERO(&except_fds);
              FD_SET(self->socket, &fds);
              FD_SET(self->socket, &except_fds);
!             ret = select(1, NULL, &fds, &except_fds, timeout > 0 ? &tm : NULL);
              gerrno = SOCK_ERRNO;
              if (0 < ret)
                  break;
***************
*** 497,503 ****
              tm.tv_sec = retry_count;
              tm.tv_usec = 0;
          }
!         ret = select((int) sock->socket + 1, output ? NULL : &fds, output ? &fds : NULL, &except_fds, no_timeout ?
NULL: &tm); 
          gerrno = SOCK_ERRNO;
      } while (ret < 0 && EINTR == gerrno);
      if (retry_count < 0)
--- 497,503 ----
              tm.tv_sec = retry_count;
              tm.tv_usec = 0;
          }
!         ret = select(1, output ? NULL : &fds, output ? &fds : NULL, &except_fds, no_timeout ? NULL : &tm);
          gerrno = SOCK_ERRNO;
      } while (ret < 0 && EINTR == gerrno);
      if (retry_count < 0)