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