+ if (!pad)
+ return;
+ /*
+ * It's OK to have a blocking operation here because we already made
+ * sure that the PCM output buffer is (nearly) empty.
+ */
+ snd_pcm_nonblock(pad->handle, 0);
+ snd_pcm_drain(pad->handle);
+ snd_pcm_close(pad->handle);
+ snd_config_update_free_global();
+ free(pad);
+}
+
+static void alsa_write_post_select(__a_unused struct sched *s,
+ struct task *t)
+{
+ struct writer_node *wn = container_of(t, struct writer_node, task);
+ struct private_alsa_write_data *pad = wn->private_data;
+ struct btr_node *btrn = wn->btrn;
+ char *data;
+ size_t bytes;
+ snd_pcm_sframes_t frames;
+ int ret;
+
+again:
+ t->error = 0;
+ ret = btr_node_status(btrn, wn->min_iqs, BTR_NT_LEAF);
+ if (ret == 0)
+ return;
+ btr_merge(btrn, wn->min_iqs);
+ bytes = btr_next_buffer(btrn, &data);
+ if (ret < 0 || bytes < wn->min_iqs) { /* eof */
+ assert(btr_no_parent(btrn));
+ ret = -E_ALSA_EOF;
+ if (!pad)
+ goto err;
+ /* wait until pending frames are played */
+ if (pad->drain_barrier.tv_sec == 0) {
+ PARA_DEBUG_LOG("waiting for device to drain\n");
+ tv_add(now, &(struct timeval)EMBRACE(0, 200 * 1000),
+ &pad->drain_barrier);
+ return;
+ }
+ if (tv_diff(now, &pad->drain_barrier, NULL) > 0)
+ goto err;
+ return;