[LTP] [PATCH v2 1/2] lib: add safe_pthread_create() & safe_pthread_join()

[Cyril Hrubis <chrubis@suse.cz>]

Hi!
> > Technically the thread_id does not need to be numeric type, POSIX
> > defines it as a opaque, may be structure as well.
> 
> We could print in hex like this:
> 
> if (rval) {
>      unsigned int i;
>      unsigned char *ptr = (unsigned char *)&thread_id;
>      size_t tid_size = sizeof(thread_id);
>      char buf[tid_size * 2 + 1];
> 
>      for (i = 0; i < tid_size; ++i)
>          sprintf(buf + i * 2, "%02x", ptr[i]);
> 
>      tst_brk_(file, lineno, TBROK,
>               "pthread_join(%s,%p) failed: %s", buf, retval, ...);
> }
> 
> But bytes might be in different order due to endianness,
> supposing we compare this value with "%lx", e.g. on x86_64
> 
> 00971fe3257f0000 vs 7f25e31f9700 (%lx)
> 
> What do you think?

I'm starting to consider not printing the value at all, since it's not
that important as gdb and strace pthread ids are not related to the
value of pthread_t. We can just print "pthread_join(..., %p)" instead.

Or we can add a configure check if pthread_t is actually numeric.
Something as:

	pthread_t *t = (unsigned long*)NULL;

Should fail with -Werror unless pthread_t is defined as unsigned long.

Then we can proceed with printing it with "%ul" if the check was OK, but
I'm not sure that it's worth of the work.

-- 
Cyril Hrubis
chrubis@suse.cz