socket leak in FreeBSD 4.7

[Scot Loach]

If I execute the following program on a FreeBSD 4.7 system:

int main()
{
    for (int i = 0; i < 70000; i++)
    {
        socket(PF_INET, SOCK_STREAM, 0);
    }
    return 0;
}
the sockets never seem to be freed.

vmstat tells me the memory is still in use:

bash-2.05a$ vmstat -z

ITEM            SIZE     LIMIT    USED    FREE  REQUESTS

tcpcb:           544,   106000,  65557,   4474,    70029
udpcb:           192,   106000,      7,     35,      481
unpcb:           160,        0,      7,     43,       78
socket:          192,   106000,  65571,   4487,    70639

However, fstat and sockstat do not show a large number of sockets.

netstat shows them, and they look like this:

tcp4       0      0  *.*                    *.*                    CLOSED


If I explicitly close the sockets before the program exits, this does not
occur.  However I'm worried about the case where a high-volume server exits
unexpectedly and leaks sockets.

Any ideas of what might be wrong?