Question over POSIX compliancy of pthread_once_t

[Garrett Cooper]

PTHREAD_ONCE_INIT / pthread_once_t isn't tersely defined according to
pthread(3) or sys/types.h at on the opengroup pages [1, 2, 3]

FreeBSD defines it as follows:

/usr/include/pthread.h:#define PTHREAD_ONCE_INIT   { PTHREAD_NEEDS_INIT, NULL }

/* ... */

/*
 * Once definitions.
 */
struct pthread_once {
        int             state;
        pthread_mutex_t mutex;
};

glibc-2.7 has PTHREAD_ONCE_INIT defined differently [4]:

  208 /* Single execution handling.  */
  209 #define PTHREAD_ONCE_INIT 0

I can't determine which one is semantically correct.

Thanks,
-Garrett

1. http://www.opengroup.org/onlinepubs/000095399/basedefs/pthread.h.html
2. http://www.opengroup.org/onlinepubs/000095399/functions/pthread_once.html
3. http://www.opengroup.org/onlinepubs/000095399/basedefs/sys/types.h.html
4. http://fxr.watson.org/fxr/source/nptl/sysdeps/pthread/pthread.h?v=GLIBC27#L209

PS I found a workaround for this issue at compile-time and run-time in
the test, but I found this to be an odd delta.