sem_open / how to use NPTL?

["Viktor Horvath" <duke586@hotmail.com>]

Hello everybody,

forgive me for bothering you, but after hours and hours of searching, I'm
stuck. For my university, I've to program some easy things with POSIX.4
semaphores. I know that I need kernel 2.6 and NPTL for that, and I have
kernel 2.6.7, gcc 3.3.5 and libc6-i686 well installed. But a minimal
program, shown below, compiled with "gcc -o minimal -lpthread minimal.c"
keeps saying "sem_open: function not implemented" as if I were still using
old LinuxThreads. However, getconf says:

$ getconf _POSIX_SEMAPHORES
1
$ getconf GNU_LIBPTHREAD_VERSION
NPTL 0.60

On Fedora Cora 2 (computer at my university that I connected via ssh), it
works flawlessly. What am I missing?

Thanks for reading,
have a nice day,
Viktor.


### minimal.c

#define _POSIX_SOURCE 1
#define  _XOPEN_SOURCE 1
#include <unistd.h>
#include <stdio.h>
#include <stdlib.h>
#include <sys/wait.h>
#include <errno.h>
#include <fcntl.h>
#include <pthread.h>
#include <semaphore.h>

int main (int argc, char **argv) {
 sem_t* mysem;
 if ((mysem = sem_open("/mysem", O_CREAT, S_IRWXU, 1)) == SEM_FAILED) {
   perror("sem_open");
   return EXIT_FAILURE;
 }
}