Using futex syscall to implement sleep

futexsleep.c

#include <stdio.h>
#include <stdint.h>
#include <time.h>
#include <unistd.h>
#include <sys/syscall.h>
#include <linux/futex.h>

int
futex_sleep (time_t seconds, long nanoseconds)
{
  uint32_t futexWord = 0;
  struct timespec timeout = { seconds, nanoseconds };
  return syscall (SYS_futex, &futexWord, FUTEX_WAIT, futexWord, &timeout,
		  NULL, 0);
}

int
main ()
{
  time_t secs = 2;
  printf ("Before futex_sleep for %ld seconds\n", secs);
  futex_sleep (2, 0);
  printf ("After futex_sleep\n");
  return 0;
}