Hey guys.
I've been searching for a hook to use when flushing all caches (with drush and from the admin UI) in order to clear varnish caches as well, but I couldn't find any. The only one invoked in drupal_flush_all_caches() is actually used to add extra tables to flush data from and since it's used by cron as well, it's not really an option.
I do care about the kitties but at this point I'm thinking of adding a new module_invoke_all('all_caches_flushed') in drupal_flush_all_caches() right after the foreach($cache_tables...) with the cache_clear_all().
Any other ideas?
Thanks,
Marius