------- Comment #7 from jakub at gcc dot gnu dot org 2009-06-07 13:07 -------
valgrind just isn't smart enough to understand it.
Obviously --enable-linux-futex build has a lot of synchronization primitives
that are beyond what valgrind is able to understand, but even with the posix
only primitives e.g.:
static inline void *gomp_ptrlock_get (gomp_ptrlock_t *ptrlock)
{
if (ptrlock->ptr != NULL)
return ptrlock->ptr;
gomp_mutex_lock (&ptrlock->lock);
if (ptrlock->ptr != NULL)
{
gomp_mutex_unlock (&ptrlock->lock);
return ptrlock->ptr;
}
return NULL;
}
is not something valgrind can understand. Try removing the first if/return and
see if it helps drd. The reason why it is safe to do is that all supported
libgomp targets have atomic pointer-sized loads/stores, and the pointer always
starts as NULL and is only set to non-NULL value inside of a critical section
guarded by the associated lock. Once it is non-NULL, it never changes its
value again. So, if the inline sees the value non-NULL, it can safely assume
it will be non-NULL all the time and doesn't have to take the lock...
--
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=40362
