{
AVInputFormat **p = last_iformat;
- format->next = NULL;
- while(*p || avpriv_atomic_ptr_cas((void * volatile *)p, NULL, format))
+ // Note, format could be added after the first 2 checks but that implies that *p is no longer NULL
+ while(p != &format->next && !format->next && avpriv_atomic_ptr_cas((void * volatile *)p, NULL, format))
p = &(*p)->next;
- last_iformat = &format->next;
+
+ if (!format->next)
+ last_iformat = &format->next;
}
void av_register_output_format(AVOutputFormat *format)
{
AVOutputFormat **p = last_oformat;
- format->next = NULL;
- while(*p || avpriv_atomic_ptr_cas((void * volatile *)p, NULL, format))
+ // Note, format could be added after the first 2 checks but that implies that *p is no longer NULL
+ while(p != &format->next && !format->next && avpriv_atomic_ptr_cas((void * volatile *)p, NULL, format))
p = &(*p)->next;
- last_oformat = &format->next;
+
+ if (!format->next)
+ last_oformat = &format->next;
}
int av_match_ext(const char *filename, const char *extensions)