+ /* The coreaudio-backend calls thread_init_callback() if
+ * the hardware changes or pthread_self() changes.
+ *
+ * However there are cases when neither holds true, yet
+ * the thread-pool changes: e.g. connect a headphone to
+ * a shared mic/headphone jack.
+ * It's probably related to, or caused by clocksource changes.
+ *
+ * For reasons yet unknown Glib::Threads::Private() can
+ * use a different thread-private in the same pthread
+ * (coreaudio render callback).
+ *
+ * Coreaudio must set something which influences
+ * pthread_key_t uniqness or reset the key using
+ * pthread_getspecific().
+ */
+ if (! SessionEvent::has_per_thread_pool ()) {
+ thread_init_callback (NULL);
+ }
+