Re: Too-many-files errors on OS X - Mailing list pgsql-hackers

--On Sunday, February 22, 2004 23:00:31 -0500 Tom Lane <tgl@sss.pgh.pa.us>
wrote:

> Kevin Brown <kevin@sysexperts.com> writes:
>> I wasn't able to test on HP-UX
>
> I get the same result on HPUX, after whacking the test program around
> a bit: no change in the number of files we can open.  Confirmations on
> other platforms please, anyone?
>
> For anyone else who has problems getting it to compile, try copying
> the relevant version of pg_dlopen from src/backend/port/dynloader/.
> I attach the code I actually ran on HPUX.
>
>             regards, tom lane
>
On FreeBSD 5:

$ ./eatfds3 /usr/local/lib/libpq.so /usr/lib/libm.so
dup() failed: Too many open files
Was able to use 7146 file descriptors
dup() failed: Too many open files
Was able to use 7146 file descriptors after opening 2 shared libs
$

On UnixWare 7.1.4:
$ ./eatfds3 /usr/lib/libpq.so.3 /usr/lib/libm.so.1
dup() failed: Too many open files
Was able to use 2045 file descriptors
dup() failed: Too many open files
Was able to use 2045 file descriptors after opening 2 shared libs
$


I had to hack on the code some more for FreeBSD:
(the realloc call needed the multiplication).  I ran this same code
on UnixWare.





$ cat eatfds3.c
#include <stdio.h>
#include <string.h>
#include <errno.h>
#include <stdlib.h>
#include <unistd.h>
#include <dlfcn.h>
// these seem to be needed on HPUX:
//#include <a.out.h>
//#include <dl.h>

int *fd;
int size = 3072;

void *
pg_dlopen(char *filename)
{       /*        * Use BIND_IMMEDIATE so that undefined symbols cause a failure
return        * from shl_load(), rather than an abort() later on when we attempt
to        * call the library!        */       caddr_t         handle = dlopen(filename,
                     RTLD_LAZY); 
       return (void *) handle;
}


int eatallfds(void) {       int i = 0;       int j, myfd;
       while (1) {               myfd = dup(0);               if (myfd < 0) {                       fprintf (stderr,
"dup()failed: %s\n",  
strerror(errno));                       break;               }               if (i >= size) {
size*= 2;                       fd = realloc(fd, size * sizeof(*fd));                       if (fd == NULL) {
                   fprintf (stderr, "Can't allocate: %s\n",
strerror(errno));                              fprintf (stderr, "Had used %d  
descriptors\n",                                               i);                               exit(1);
      }               }               fd[i++] = myfd;       }       for (j = 0 ; j < i ; ++j) {
close(fd[j]);      }       return i; 
}


int main (int argc, char *argv[]) {       int n, na;       int i;       void *addr;
       size = 3072;       fd = malloc((size + 1) * sizeof(*fd));       if (fd == NULL) {               fprintf (stderr,
"Can'tallocate: %s\n", strerror(errno));               return 1;       }       n = eatallfds();       printf ("Was able
touse %d file descriptors\n", n); 
       na = 0;       for (i = 1 ; i < argc ; ++i) {               addr = pg_dlopen(argv[i]);               if (addr !=
NULL)na++;       }       n = eatallfds();       printf ("Was able to use %d file descriptors after opening %d  
shared libs\n", n, na);       return 0;
}

$



--
Larry Rosenman                     http://www.lerctr.org/~ler
Phone: +1 972-414-9812                 E-Mail: ler@lerctr.org
US Mail: 1905 Steamboat Springs Drive, Garland, TX 75044-6749