/* Owned by this*/
struct bt_private_port *priv_port;
+
+ /*
+ * This flag is true if the upstream notification iterator's
+ * current notification must be considered for the multiplexing
+ * operations. If the upstream iterator returns
+ * BT_NOTIFICATION_ITERATOR_STATUS_AGAIN, then this object
+ * is considered invalid, because its current notification is
+ * still the previous one, but we already took it into account.
+ *
+ * The value of this flag is not important if notif_iter above
+ * is NULL (which means the upstream iterator is finished).
+ */
+ bool is_valid;
};
struct muxer_notif_iter {
*/
GPtrArray *muxer_upstream_notif_iters;
- /* Array of struct muxer_upstream_notif_iter * (weak refs) */
- GList *muxer_upstream_notif_iters_to_retry;
-
/*
* List of "recently" connected input ports (owned by this) to
* handle by this muxer notification iterator.
/* Next thing to return by the "next" method */
struct bt_notification_iterator_next_return next_next_return;
- int64_t next_next_return_ts_ns;
/* Last time returned in a notification */
int64_t last_returned_ts_ns;
muxer_upstream_notif_iter->notif_iter = bt_get(notif_iter);
muxer_upstream_notif_iter->priv_port = bt_get(priv_port);
+ muxer_upstream_notif_iter->is_valid = false;
g_ptr_array_add(muxer_notif_iter->muxer_upstream_notif_iters,
muxer_upstream_notif_iter);
return muxer_upstream_notif_iter;
}
-static inline
-bool muxer_notif_iter_has_upstream_notif_iter_to_retry(
- struct muxer_notif_iter *muxer_notif_iter)
-{
- assert(muxer_notif_iter);
- return muxer_notif_iter->muxer_upstream_notif_iters_to_retry != NULL;
-}
-
-static
-void muxer_notif_iter_add_upstream_notif_iter_to_retry(
- struct muxer_notif_iter *muxer_notif_iter,
- struct muxer_upstream_notif_iter *muxer_upstream_notif_iter)
-{
- assert(muxer_notif_iter);
- assert(muxer_upstream_notif_iter);
- muxer_notif_iter->muxer_upstream_notif_iters_to_retry =
- g_list_append(
- muxer_notif_iter->muxer_upstream_notif_iters_to_retry,
- muxer_upstream_notif_iter);
-}
-
static
int ensure_available_input_port(struct bt_private_component *priv_comp)
{
}
static
-int muxer_upstream_notif_iter_next(struct muxer_notif_iter *muxer_notif_iter,
+enum bt_notification_iterator_status muxer_upstream_notif_iter_next(
struct muxer_upstream_notif_iter *muxer_upstream_notif_iter)
{
- int ret = 0;
- enum bt_notification_iterator_status next_status;
+ enum bt_notification_iterator_status status;
- next_status = bt_notification_iterator_next(
+ status = bt_notification_iterator_next(
muxer_upstream_notif_iter->notif_iter);
- switch (next_status) {
+ switch (status) {
case BT_NOTIFICATION_ITERATOR_STATUS_OK:
- /* Everything okay */
+ /*
+ * Notification iterator's current notification is valid:
+ * it must be considered for muxing operations.
+ */
+ muxer_upstream_notif_iter->is_valid = true;
break;
case BT_NOTIFICATION_ITERATOR_STATUS_AGAIN:
- muxer_notif_iter_add_upstream_notif_iter_to_retry(
- muxer_notif_iter, muxer_upstream_notif_iter);
+ /*
+ * Notification iterator's current notification is not
+ * valid anymore. Return
+ * BT_NOTIFICATION_ITERATOR_STATUS_AGAIN
+ * immediately.
+ */
+ muxer_upstream_notif_iter->is_valid = false;
break;
case BT_NOTIFICATION_ITERATOR_STATUS_END:
/*
* notification.
*/
BT_PUT(muxer_upstream_notif_iter->notif_iter);
- goto end;
+ muxer_upstream_notif_iter->is_valid = false;
+ status = BT_NOTIFICATION_ITERATOR_STATUS_OK;
+ break;
default:
/* Error or unsupported status code */
- ret = next_status;
+ status = BT_NOTIFICATION_ITERATOR_STATUS_ERROR;
+ break;
}
-end:
- return ret;
+ return status;
}
static
-int muxer_notif_iter_handle_newly_connected_ports(struct muxer_comp *muxer_comp,
+int muxer_notif_iter_handle_newly_connected_ports(
struct muxer_notif_iter *muxer_notif_iter)
{
- struct bt_component *comp = NULL;
int ret = 0;
- comp = bt_component_from_private_component(muxer_comp->priv_comp);
- assert(comp);
-
/*
* Here we create one upstream notification iterator for each
- * newly connected port. The list of newly connected ports to
- * handle here is updated by muxer_port_connected().
- *
- * An initial "next" operation is performed on each new upstream
- * notification iterator. The possible return values of this
- * initial "next" operation are:
- *
- * * BT_NOTIFICATION_ITERATOR_STATUS_OK: Perfect, we have a
- * current notification.
- *
- * * BT_NOTIFICATION_ITERATOR_STATUS_AGAIN: No notification so
- * far, but the muxer upstream notification iterator is added
- * to the list of upstream notification iterators to retry
- * before finding the next youngest notification.
- *
- * * BT_NOTIFICATION_ITERATOR_STATUS_END: No notification, and
- * we immediately release the upstream notification iterator
- * because it's useless.
- *
- * A possible side effect of this initial "next" operation, on
- * each notification iterator, is the connection of a new port.
- * In this case the list of newly connected ports is updated and
- * this loop continues.
- *
- * Once this loop finishes successfully, the set of upstream
- * notification iterators is considered _stable_, that is, it is
- * safe, if no notification iterators must be retried, to select
- * the youngest notification amongst them to be returned by the
- * next "next" method call.
+ * newly connected port. We do not perform an initial "next" on
+ * those new upstream notification iterators: they are
+ * invalidated, to be validated later. The list of newly
+ * connected ports to handle here is updated by
+ * muxer_port_connected().
*/
while (true) {
GList *node = muxer_notif_iter->newly_connected_priv_ports;
/*
* Looks like this port is not connected
* anymore: we can't create an upstream
- * notification iterator on its connection in
- * this case.
+ * notification iterator on its (non-existing)
+ * connection in this case.
*/
goto remove_node;
}
goto error;
}
- ret = muxer_upstream_notif_iter_next(muxer_notif_iter,
- muxer_upstream_notif_iter);
- if (ret) {
- goto error;
- }
-
remove_node:
bt_put(upstream_notif_iter);
bt_put(port);
goto end;
error:
- if (ret == 0) {
+ if (ret >= 0) {
ret = -1;
}
end:
- bt_put(comp);
return ret;
}
notif);
break;
default:
- /*
- * All the other notifications have a higher
- * priority.
- */
+ /* All the other notifications have a higher priority */
*ts_ns = last_returned_ts_ns;
goto end;
}
continue;
}
+ assert(cur_muxer_upstream_notif_iter->is_valid);
notif = bt_notification_iterator_get_notification(
cur_muxer_upstream_notif_iter->notif_iter);
assert(notif);
}
static
-int muxer_notif_iter_set_next_next_return(struct muxer_comp *muxer_comp,
- struct muxer_notif_iter *muxer_notif_iter)
+enum bt_notification_iterator_status validate_muxer_upstream_notif_iter(
+ struct muxer_upstream_notif_iter *muxer_upstream_notif_iter)
{
- struct muxer_upstream_notif_iter *muxer_upstream_notif_iter;
- enum bt_notification_iterator_status notif_iter_status;
- int ret = 0;
+ enum bt_notification_iterator_status status =
+ BT_NOTIFICATION_ITERATOR_STATUS_OK;
- /*
- * Previous operations might have connected ports. They must be
- * considered when finding the youngest notification because
- * their upstream notification iterator does not exist yet.
- */
- ret = muxer_notif_iter_handle_newly_connected_ports(muxer_comp,
- muxer_notif_iter);
- if (ret) {
- muxer_notif_iter->next_next_return.status =
- BT_NOTIFICATION_ITERATOR_STATUS_ERROR;
- BT_PUT(muxer_notif_iter->next_next_return.notification);
+ if (muxer_upstream_notif_iter->is_valid ||
+ !muxer_upstream_notif_iter->notif_iter) {
goto end;
}
- assert(!muxer_notif_iter->newly_connected_priv_ports);
+ status = muxer_upstream_notif_iter_next(muxer_upstream_notif_iter);
+
+end:
+ return status;
+}
+
+static
+enum bt_notification_iterator_status validate_muxer_upstream_notif_iters(
+ struct muxer_notif_iter *muxer_notif_iter)
+{
+ enum bt_notification_iterator_status status =
+ BT_NOTIFICATION_ITERATOR_STATUS_OK;
+ size_t i;
+
+ for (i = 0; i < muxer_notif_iter->muxer_upstream_notif_iters->len; i++) {
+ struct muxer_upstream_notif_iter *muxer_upstream_notif_iter =
+ g_ptr_array_index(
+ muxer_notif_iter->muxer_upstream_notif_iters,
+ i);
+
+ status = validate_muxer_upstream_notif_iter(
+ muxer_upstream_notif_iter);
+ if (status != BT_NOTIFICATION_ITERATOR_STATUS_OK) {
+ goto end;
+ }
+ }
+
+end:
+ return status;
+}
+
+static
+struct bt_notification_iterator_next_return muxer_notif_iter_do_next(
+ struct muxer_comp *muxer_comp,
+ struct muxer_notif_iter *muxer_notif_iter)
+{
+ struct muxer_upstream_notif_iter *muxer_upstream_notif_iter = NULL;
+ struct bt_notification_iterator_next_return next_return = {
+ .notification = NULL,
+ .status = BT_NOTIFICATION_ITERATOR_STATUS_OK,
+ };
+ int64_t next_return_ts;
+
+ while (true) {
+ int ret = muxer_notif_iter_handle_newly_connected_ports(
+ muxer_notif_iter);
+
+ if (ret) {
+ next_return.status =
+ BT_NOTIFICATION_ITERATOR_STATUS_ERROR;
+ goto end;
+ }
+
+ next_return.status =
+ validate_muxer_upstream_notif_iters(muxer_notif_iter);
+ if (next_return.status != BT_NOTIFICATION_ITERATOR_STATUS_OK) {
+ goto end;
+ }
- if (muxer_notif_iter_has_upstream_notif_iter_to_retry(
- muxer_notif_iter)) {
/*
- * At least one upstream notification iterator to retry:
- * try again later, because we cannot find the youngest
- * notification if we don't have the current
- * notification of each upstream notification iterator.
+ * At this point, we know that all the existing upstream
+ * notification iterators are valid. However the
+ * operations to validate them (during
+ * validate_muxer_upstream_notif_iters()) may have
+ * connected new ports. If no ports were connected
+ * during this operation, exit the loop.
*/
- muxer_notif_iter->next_next_return.status =
- BT_NOTIFICATION_ITERATOR_STATUS_AGAIN;
- BT_PUT(muxer_notif_iter->next_next_return.notification);
- goto end;
+ if (!muxer_notif_iter->newly_connected_priv_ports) {
+ break;
+ }
}
+ assert(!muxer_notif_iter->newly_connected_priv_ports);
+
/*
- * At this point we know that all our connected ports have an
- * upstream notification iterator, and that all those iterators
- * have a current notification (stable state). It is safe to
- * find the youngest notification. It is possible that calling
- * "next" on its iterator will connect new ports. This will be
- * handled by the next call to
- * muxer_notif_iter_set_next_next_return().
+ * At this point we know that all the existing upstream
+ * notification iterators are valid. We can find the one,
+ * amongst those, of which the current notification is the
+ * youngest.
*/
- notif_iter_status =
+ next_return.status =
muxer_notif_iter_youngest_upstream_notif_iter(muxer_comp,
muxer_notif_iter, &muxer_upstream_notif_iter,
- &muxer_notif_iter->next_next_return_ts_ns);
- if (notif_iter_status == BT_NOTIFICATION_ITERATOR_STATUS_END) {
- /* No more active upstream notification iterator */
- muxer_notif_iter->next_next_return.status =
- BT_NOTIFICATION_ITERATOR_STATUS_END;
- BT_PUT(muxer_notif_iter->next_next_return.notification);
- goto end;
- }
-
- if (notif_iter_status < 0) {
- ret = -1;
+ &next_return_ts);
+ if (next_return.status < 0 ||
+ next_return.status == BT_NOTIFICATION_ITERATOR_STATUS_END) {
goto end;
}
- assert(notif_iter_status == BT_NOTIFICATION_ITERATOR_STATUS_OK);
- BT_PUT(muxer_notif_iter->next_next_return.notification);
- muxer_notif_iter->next_next_return.notification =
- bt_notification_iterator_get_notification(
- muxer_upstream_notif_iter->notif_iter);
- assert(muxer_notif_iter->next_next_return.notification);
- muxer_notif_iter->next_next_return.status =
- BT_NOTIFICATION_ITERATOR_STATUS_OK;
- ret = muxer_upstream_notif_iter_next(muxer_notif_iter,
- muxer_upstream_notif_iter);
- if (ret) {
+ if (next_return_ts < muxer_notif_iter->last_returned_ts_ns) {
+ next_return.status = BT_NOTIFICATION_ITERATOR_STATUS_ERROR;
goto end;
}
- /*
- * Here we have the next "next" return value. It won't change
- * until it is returned by the next call to our "next" method.
- * If its time is less than the time of the last notification
- * that our "next" method returned, then fail because the
- * muxer's output wouldn't be monotonic.
- */
- if (muxer_notif_iter->next_next_return_ts_ns <
- muxer_notif_iter->last_returned_ts_ns) {
- ret = -1;
- goto end;
- }
+ assert(next_return.status == BT_NOTIFICATION_ITERATOR_STATUS_OK);
+ assert(muxer_upstream_notif_iter);
+ next_return.notification = bt_notification_iterator_get_notification(
+ muxer_upstream_notif_iter->notif_iter);
+ assert(next_return.notification);
/*
- * We are now sure that the next "next" return value will not
- * change until it is returned by this muxer notification
- * iterator (unless there's a fatal error). It is now safe to
- * set the last returned time to this one.
+ * We invalidate the upstream notification iterator so that, the
+ * next time this function is called,
+ * validate_muxer_upstream_notif_iters() will make it valid.
*/
- muxer_notif_iter->last_returned_ts_ns =
- muxer_notif_iter->next_next_return_ts_ns;
+ muxer_upstream_notif_iter->is_valid = false;
+ muxer_notif_iter->last_returned_ts_ns = next_return_ts;
end:
- return ret;
+ return next_return;
}
static
muxer_notif_iter->muxer_upstream_notif_iters, TRUE);
}
- if (muxer_notif_iter->muxer_upstream_notif_iters_to_retry) {
- g_list_free(muxer_notif_iter->muxer_upstream_notif_iters_to_retry);
- }
-
for (node = muxer_notif_iter->newly_connected_priv_ports;
node; node = g_list_next(node)) {
bt_put(node->data);
if (muxer_comp->initializing_muxer_notif_iter) {
/*
- * Weird, unhandled situation: downstream creates a
- * muxer notification iterator while creating another
- * muxer notification iterator (same component).
+ * Weird, unhandled situation detected: downstream
+ * creates a muxer notification iterator while creating
+ * another muxer notification iterator (same component).
*/
goto error;
}
goto error;
}
- /* Set the initial "next" return value */
- ret = muxer_notif_iter_set_next_next_return(muxer_comp,
- muxer_notif_iter);
- if (ret) {
- goto error;
- }
-
ret = bt_private_notification_iterator_set_user_data(priv_notif_iter,
muxer_notif_iter);
assert(ret == 0);
struct bt_notification_iterator_next_return muxer_notif_iter_next(
struct bt_private_notification_iterator *priv_notif_iter)
{
- struct bt_notification_iterator_next_return next_ret = {
- .notification = NULL,
- };
+ struct bt_notification_iterator_next_return next_ret;
struct muxer_notif_iter *muxer_notif_iter =
bt_private_notification_iterator_get_user_data(priv_notif_iter);
struct bt_private_component *priv_comp = NULL;
struct muxer_comp *muxer_comp = NULL;
- GList *retry_node;
- int ret;
assert(muxer_notif_iter);
priv_comp = bt_private_notification_iterator_get_private_component(
/* Are we in an error state set elsewhere? */
if (unlikely(muxer_comp->error)) {
- goto error;
- }
-
- /*
- * If we have upstream notification iterators to retry, retry
- * them now. Each one we find which now has a notification or
- * is in "end" state, we set it to NULL in this array. Then
- * we remove all the NULL values from this array.
- */
- retry_node = muxer_notif_iter->muxer_upstream_notif_iters_to_retry;
- while (retry_node) {
- struct muxer_upstream_notif_iter *muxer_upstream_notif_iter =
- retry_node->data;
- enum bt_notification_iterator_status status;
- GList *next_retry_node = g_list_next(retry_node);
-
- assert(muxer_upstream_notif_iter->notif_iter);
- status = bt_notification_iterator_next(
- muxer_upstream_notif_iter->notif_iter);
- if (status < 0) {
- goto error;
- }
-
- if (status == BT_NOTIFICATION_ITERATOR_STATUS_END) {
- /*
- * This upstream notification iterator is done.
- * Put the iterator and remove node from list.
- */
- BT_PUT(muxer_upstream_notif_iter->notif_iter);
- muxer_notif_iter->muxer_upstream_notif_iters_to_retry =
- g_list_delete_link(
- muxer_notif_iter->muxer_upstream_notif_iters_to_retry,
- retry_node);
- retry_node = next_retry_node;
- continue;
- }
-
- assert(status == BT_NOTIFICATION_ITERATOR_STATUS_OK ||
- status == BT_NOTIFICATION_ITERATOR_STATUS_AGAIN);
-
- if (status == BT_NOTIFICATION_ITERATOR_STATUS_OK) {
- /*
- * This upstream notification iterator now has.
- * a notification. Remove it from this list.
- */
- muxer_notif_iter->muxer_upstream_notif_iters_to_retry =
- g_list_delete_link(
- muxer_notif_iter->muxer_upstream_notif_iters_to_retry,
- retry_node);
- }
-
- retry_node = next_retry_node;
- }
-
- /* Take our next "next" next return value */
- next_ret = muxer_notif_iter->next_next_return;
- muxer_notif_iter->next_next_return.status =
- BT_NOTIFICATION_ITERATOR_STATUS_ERROR;
- muxer_notif_iter->next_next_return.notification = NULL;
-
- /* Set the next "next" return value */
- ret = muxer_notif_iter_set_next_next_return(muxer_comp,
- muxer_notif_iter);
- if (ret) {
- goto error;
+ next_ret.notification = NULL;
+ next_ret.status = BT_NOTIFICATION_ITERATOR_STATUS_ERROR;
+ goto end;
}
- goto end;
-
-error:
- /*
- * Technically we already have a next "next" return value which
- * is ready for this call, but we're failing within this call,
- * so discard this buffer and return the error ASAP.
- */
- BT_PUT(next_ret.notification);
- next_ret.status = BT_NOTIFICATION_ITERATOR_STATUS_ERROR;
+ next_ret = muxer_notif_iter_do_next(muxer_comp, muxer_notif_iter);
end:
bt_put(priv_comp);
muxer_comp->available_input_ports--;
ret = ensure_available_input_port(priv_comp);
if (ret) {
+ /*
+ * Only way to report an error later since this
+ * method does not return anything.
+ */
muxer_comp->error = true;
goto end;
}
muxer_notif_iter->newly_connected_priv_ports,
bt_get(self_private_port));
if (!muxer_notif_iter->newly_connected_priv_ports) {
+ /* Put reference taken by bt_get() above */
bt_put(self_private_port);
muxer_comp->error = true;
goto end;
* iterators which were already created thanks to connected
* ports. The fact that the port is disconnected does not cancel
* the upstream notification iterators created using its
- * connection: they still exist. The only way to remove an
- * upstream notification iterator is for its "next" operation to
- * return BT_NOTIFICATION_ITERATOR_STATUS_END.
+ * connection: they still exist, even if the connection is dead.
+ * The only way to remove an upstream notification iterator is
+ * for its "next" operation to return
+ * BT_NOTIFICATION_ITERATOR_STATUS_END.
*/
if (bt_port_get_type(port) == BT_PORT_TYPE_INPUT) {
/* One more available input port */
projects / babeltrace.git / commitdiff
