Squid 1.2b24 incorrectly detects FDs in Linux 2.1.x

Hello all,

Newer copies of Linux 2.1.11x contain by default 1024 file descriptors
active on a machine, however Squid detects only 256. Doing a open() loop
until you run out will properly detect this.

Unfortunatly, this is because <linux/limits.h> defines OPEN_MAX as 256
(which defines NOFILE as OPEN_MAX), but NR_OPEN as 1024.

What is odd is that the following code snipit (which looks like it should be
used instead of NOFILE or OPEN_MAX) gives 1024:

#include <sys/time.h>
#include <sys/resource.h>
#include <unistd.h>

main() {
    struct rlimit rl;
    if (getrlimit(RLIMIT_NOFILE, &rl) < 0) {
        perror("getrlimit: RLIMIT_NOFILE");
    } else {
        rl.rlim_cur = rl.rlim_max; /* set it to the max */
        if (setrlimit(RLIMIT_NOFILE, &rl) < 0) {
            perror("setrlimit: RLIMIT_NOFILE");
        } else
            printf("%d", rl.rlim_cur);
    }
}

But in configure, it doesn't seem to use rl.rlim_max if it succeeded (in
fact, it doesn't do anything with the above code snipit as far as I can
tell)

I've attached a diff for configure.in to this message, of course... autoconf
will need to be run to rebuild the main configure before it works :)

It basically uses setrlimit, but double-checks the value against an open()
loop (as well as any other methods such as NOFILE or getdtablesize()) and
chooses which ever returns the largest number.

Jordan

--
Jordan Mendelson     : http://jordy.wserv.com
Web Services, Inc.   : http://www.wserv.com
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`
end