(module nanosleep (nanosleep)

  (import (scheme) (chicken foreign))

  (foreign-declare "
  #include <time.h>
  #include <errno.h>")

  (define nanosleep
    (foreign-lambda* bool ((int seconds) (long nanoseconds))
      "
      struct timespec req, rem;
      req.tv_sec = seconds;
      req.tv_nsec = nanoseconds;
      rem.tv_sec = rem.tv_nsec = 0;
      errno = 0;
      if (nanosleep(&req, &rem) == 0)
      {
        C_return(1);
      }
      if (errno != EINTR)
      {
        C_return(0);
      }

      /* try to sleep the remaining time, once only */
      const int rc = nanosleep(&rem, NULL);
      C_return(rc == 0 ? 1 : 0);
      "
      ))
  )