/*
- * Copyright (C) 2006-2012 Andre Noll <maan@systemlinux.org>
+ * Copyright (C) 2006-2013 Andre Noll <maan@systemlinux.org>
*
* Licensed under the GPL v2. For licencing details see COPYING.
*/
unsigned sample_format;
/** Number of channels of the current audio stream. */
unsigned channels;
- /** Serializes access to buffer tree nodes. */
+ /**
+ * Serializes access to buffer tree nodes between the writer and
+ * the callback which runs in a different thread.
+ */
int mutex;
- /** The btr node of the callback. */
+ /**
+ * The btr node of the callback.
+ *
+ * Although access to the btr node is serialized between the writer and
+ * the callback via the above mutex, this does not stop other buffer
+ * tree nodes, for example the decoder, to race against the osx
+ * callback.
+ *
+ * However, since all operations on buffer tree nodes are local in the
+ * sense that they only affect one level in the buffer tree (i.e.
+ * parent or child nodes, but not the grandparent or the
+ * grandchildren), we may work around this problem by using another
+ * buffer tree node for the callback.
+ *
+ * The writer grabs the mutex in its post_select method and pushes down
+ * the buffers to the callback node.
+ */
struct btr_node *callback_btrn;
};
{
int i;
struct writer_node *wn = cb_arg;
- struct private_osx_write_data *powd = wn->private_data;
+ struct private_osx_write_data *powd;
size_t samples_have, samples_want = 0;
+ powd = wn->private_data;
mutex_lock(powd->mutex);
+ powd = wn->private_data;
+ if (!powd || !wn->btrn)
+ goto out;
/*
* We fill with zeros if no data was yet written and we do not have
* enough to fill all buffers.
}
mutex_lock(powd->mutex);
- ret = btr_node_status(wn->btrn, wn->min_iqs, BTR_NT_LEAF);
+ ret = btr_node_status(wn->btrn, wn->min_iqs, BTR_NT_INTERNAL);
if (ret < 0)
drain_delay_nec = need_drain_delay(powd);
mutex_unlock(powd->mutex);
if (ret < 0)
goto fail;
powd = wn->private_data;
- AudioOutputUnitStart(powd->audio_unit);
+ ret = -E_UNIT_START;
+ if (AudioOutputUnitStart(powd->audio_unit) != noErr) {
+ AudioUnitUninitialize(powd->audio_unit);
+ CloseComponent(powd->audio_unit);
+ btr_remove_node(&powd->callback_btrn);
+ goto fail;
+ }
}
mutex_lock(powd->mutex);
- btr_pushdown(btrn);
- ret = btr_node_status(btrn, wn->min_iqs, BTR_NT_LEAF);
+ ret = btr_node_status(btrn, wn->min_iqs, BTR_NT_INTERNAL);
+ if (ret > 0)
+ btr_pushdown(btrn);
if (ret < 0 && need_drain_delay(powd))
ret = 0;
mutex_unlock(powd->mutex);