+/* Called from the IO thread. */
+static int source_set_state_in_io_thread_cb(pa_source *s, pa_source_state_t new_state, pa_suspend_cause_t new_suspend_cause) {
+ struct userdata *u;
+ int r;
+
+ pa_assert(s);
+ pa_assert_se(u = s->userdata);
+
+ /* It may be that only the suspend cause is changing, in which case there's
+ * nothing more to do. */
+ if (new_state == s->thread_info.state)
+ return 0;
+
+ switch (new_state) {
+ case PA_SOURCE_SUSPENDED: {
+ pa_assert(PA_SOURCE_IS_OPENED(s->thread_info.state));
+ if ((r = suspend(u)) < 0)
+ return r;
+ break;
+ }
+
+ case PA_SOURCE_IDLE:
+ case PA_SOURCE_RUNNING: {
+ if (s->thread_info.state == PA_SOURCE_INIT) {
+ if (build_pollfd(u) < 0)
+ return -PA_ERR_IO;
+ }
+
+ if (s->thread_info.state == PA_SOURCE_SUSPENDED) {
+ if ((r = unsuspend(u)) < 0)
+ return r;
+ }
+ break;
+ }
+
+ case PA_SOURCE_UNLINKED:
+ case PA_SOURCE_INIT:
+ case PA_SOURCE_INVALID_STATE:
+ break;
+ }
+
+ return 0;
+}
+