[babeltrace.git] / plugins / utils / muxer / muxer.c

/*
 * Copyright 2017 Philippe Proulx <pproulx@efficios.com>
 *
 * Permission is hereby granted, free of charge, to any person obtaining a copy
 * of this software and associated documentation files (the "Software"), to deal
 * in the Software without restriction, including without limitation the rights
 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
 * copies of the Software, and to permit persons to whom the Software is
 * furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included in
 * all copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
 * SOFTWARE.
 */

#define BT_LOG_TAG "PLUGIN-UTILS-MUXER-FLT"
#include "logging.h"

#include <babeltrace/babeltrace-internal.h>
#include <babeltrace/compat/uuid-internal.h>
#include <babeltrace/ctf-ir/clock-class.h>
#include <babeltrace/ctf-ir/event.h>
#include <babeltrace/graph/clock-class-priority-map.h>
#include <babeltrace/graph/component-filter.h>
#include <babeltrace/graph/component.h>
#include <babeltrace/graph/component-internal.h>
#include <babeltrace/graph/notification-event.h>
#include <babeltrace/graph/notification-inactivity.h>
#include <babeltrace/graph/notification-iterator.h>
#include <babeltrace/graph/notification-iterator-internal.h>
#include <babeltrace/graph/notification.h>
#include <babeltrace/graph/port.h>
#include <babeltrace/graph/private-component-filter.h>
#include <babeltrace/graph/private-component.h>
#include <babeltrace/graph/private-component.h>
#include <babeltrace/graph/private-connection.h>
#include <babeltrace/graph/private-notification-iterator.h>
#include <babeltrace/graph/private-port.h>
#include <babeltrace/graph/connection.h>
#include <babeltrace/graph/connection-internal.h>
#include <babeltrace/values-internal.h>
#include <plugins-common.h>
#include <glib.h>
#include <stdbool.h>
#include <inttypes.h>
#include <assert.h>
#include <stdlib.h>
#include <string.h>

#define ASSUME_ABSOLUTE_CLOCK_CLASSES_PARAM_NAME        "assume-absolute-clock-classes"

struct muxer_comp {
        /* Array of struct bt_private_notification_iterator * (weak refs) */
        GPtrArray *muxer_notif_iters;

        /* Weak ref */
        struct bt_private_component *priv_comp;
        unsigned int next_port_num;
        size_t available_input_ports;
        bool error;
        bool initializing_muxer_notif_iter;
        bool assume_absolute_clock_classes;
};

struct muxer_upstream_notif_iter {
        /* Owned by this, NULL if ended */
        struct bt_notification_iterator *notif_iter;

        /*
         * 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;
};

enum muxer_notif_iter_clock_class_expectation {
        MUXER_NOTIF_ITER_CLOCK_CLASS_EXPECTATION_ANY = 0,
        MUXER_NOTIF_ITER_CLOCK_CLASS_EXPECTATION_ABSOLUTE,
        MUXER_NOTIF_ITER_CLOCK_CLASS_EXPECTATION_NOT_ABS_SPEC_UUID,
        MUXER_NOTIF_ITER_CLOCK_CLASS_EXPECTATION_NOT_ABS_NO_UUID,
};

struct muxer_notif_iter {
        /*
         * Array of struct muxer_upstream_notif_iter * (owned by this).
         *
         * NOTE: This array is searched in linearly to find the youngest
         * current notification. Keep this until benchmarks confirm that
         * another data structure is faster than this for our typical
         * use cases.
         */
        GPtrArray *muxer_upstream_notif_iters;

        /*
         * List of "recently" connected input ports (weak) to
         * handle by this muxer notification iterator.
         * muxer_port_connected() adds entries to this list, and the
         * entries are removed when a notification iterator is created
         * on the port's connection and put into
         * muxer_upstream_notif_iters above by
         * muxer_notif_iter_handle_newly_connected_ports().
         */
        GList *newly_connected_priv_ports;

        /* Next thing to return by the "next" method */
        struct bt_notification_iterator_next_return next_next_return;

        /* Last time returned in a notification */
        int64_t last_returned_ts_ns;

        /* Clock class expectation state */
        enum muxer_notif_iter_clock_class_expectation clock_class_expectation;

        /*
         * Expected clock class UUID, only valid when
         * clock_class_expectation is
         * MUXER_NOTIF_ITER_CLOCK_CLASS_EXPECTATION_NOT_ABS_SPEC_UUID.
         */
        unsigned char expected_clock_class_uuid[BABELTRACE_UUID_LEN];
};

static
void destroy_muxer_upstream_notif_iter(
                struct muxer_upstream_notif_iter *muxer_upstream_notif_iter)
{
        if (!muxer_upstream_notif_iter) {
                return;
        }

        BT_LOGD("Destroying muxer's upstream notification iterator wrapper: "
                "addr=%p, notif-iter-addr=%p, is-valid=%d",
                muxer_upstream_notif_iter,
                muxer_upstream_notif_iter->notif_iter,
                muxer_upstream_notif_iter->is_valid);
        bt_put(muxer_upstream_notif_iter->notif_iter);
        g_free(muxer_upstream_notif_iter);
}

static
struct muxer_upstream_notif_iter *muxer_notif_iter_add_upstream_notif_iter(
                struct muxer_notif_iter *muxer_notif_iter,
                struct bt_notification_iterator *notif_iter,
                struct bt_private_port *priv_port)
{
        struct muxer_upstream_notif_iter *muxer_upstream_notif_iter =
                g_new0(struct muxer_upstream_notif_iter, 1);

        if (!muxer_upstream_notif_iter) {
                BT_LOGE_STR("Failed to allocate one muxer's upstream notification iterator wrapper.");
                goto end;
        }

        muxer_upstream_notif_iter->notif_iter = bt_get(notif_iter);
        muxer_upstream_notif_iter->is_valid = false;
        g_ptr_array_add(muxer_notif_iter->muxer_upstream_notif_iters,
                muxer_upstream_notif_iter);
        BT_LOGD("Added muxer's upstream notification iterator wrapper: "
                "addr=%p, muxer-notif-iter-addr=%p, notif-iter-addr=%p",
                muxer_upstream_notif_iter, muxer_notif_iter,
                notif_iter);

end:
        return muxer_upstream_notif_iter;
}

static
enum bt_component_status ensure_available_input_port(
                struct bt_private_component *priv_comp)
{
        struct muxer_comp *muxer_comp =
                bt_private_component_get_user_data(priv_comp);
        enum bt_component_status status = BT_COMPONENT_STATUS_OK;
        GString *port_name = NULL;

        assert(muxer_comp);

        if (muxer_comp->available_input_ports >= 1) {
                goto end;
        }

        port_name = g_string_new("in");
        if (!port_name) {
                BT_LOGE_STR("Failed to allocate a GString.");
                status = BT_COMPONENT_STATUS_NOMEM;
                goto end;
        }

        g_string_append_printf(port_name, "%u", muxer_comp->next_port_num);
        status = bt_private_component_filter_add_input_private_port(
                priv_comp, port_name->str, NULL, NULL);
        if (status != BT_COMPONENT_STATUS_OK) {
                BT_LOGE("Cannot add input port to muxer component: "
                        "port-name=\"%s\", comp-addr=%p, status=%s",
                        port_name->str, priv_comp,
                        bt_component_status_string(status));
                goto end;
        }

        muxer_comp->available_input_ports++;
        muxer_comp->next_port_num++;
        BT_LOGD("Added one input port to muxer component: "
                "port-name=\"%s\", comp-addr=%p",
                port_name->str, priv_comp);
end:
        if (port_name) {
                g_string_free(port_name, TRUE);
        }

        return status;
}

static
enum bt_component_status create_output_port(
                struct bt_private_component *priv_comp)
{
        return bt_private_component_filter_add_output_private_port(
                priv_comp, "out", NULL, NULL);
}

static
void destroy_muxer_comp(struct muxer_comp *muxer_comp)
{
        if (!muxer_comp) {
                return;
        }

        BT_LOGD("Destroying muxer component: muxer-comp-addr=%p, "
                "muxer-notif-iter-count=%u", muxer_comp,
                muxer_comp->muxer_notif_iters->len);

        if (muxer_comp->muxer_notif_iters) {
                g_ptr_array_free(muxer_comp->muxer_notif_iters, TRUE);
        }

        g_free(muxer_comp);
}

static
struct bt_value *get_default_params(void)
{
        struct bt_value *params;
        int ret;

        params = bt_value_map_create();
        if (!params) {
                BT_LOGE_STR("Cannot create a map value object.");
                goto error;
        }

        ret = bt_value_map_insert_bool(params,
                ASSUME_ABSOLUTE_CLOCK_CLASSES_PARAM_NAME, false);
        if (ret) {
                BT_LOGE_STR("Cannot add boolean value to map value object.");
                goto error;
        }

        goto end;

error:
        BT_PUT(params);

end:
        return params;
}

static
int configure_muxer_comp(struct muxer_comp *muxer_comp, struct bt_value *params)
{
        struct bt_value *default_params = NULL;
        struct bt_value *real_params = NULL;
        struct bt_value *assume_absolute_clock_classes = NULL;
        int ret = 0;
        bt_bool bool_val;

        default_params = get_default_params();
        if (!default_params) {
                BT_LOGE("Cannot get default parameters: "
                        "muxer-comp-addr=%p", muxer_comp);
                goto error;
        }

        real_params = bt_value_map_extend(default_params, params);
        if (!real_params) {
                BT_LOGE("Cannot extend default parameters map value: "
                        "muxer-comp-addr=%p, def-params-addr=%p, "
                        "params-addr=%p", muxer_comp, default_params,
                        params);
                goto error;
        }

        assume_absolute_clock_classes = bt_value_map_get(real_params,
                ASSUME_ABSOLUTE_CLOCK_CLASSES_PARAM_NAME);
        if (!bt_value_is_bool(assume_absolute_clock_classes)) {
                BT_LOGE("Expecting a boolean value for the `%s` parameter: "
                        "muxer-comp-addr=%p, value-type=%s",
                        ASSUME_ABSOLUTE_CLOCK_CLASSES_PARAM_NAME, muxer_comp,
                        bt_value_type_string(
                                bt_value_get_type(assume_absolute_clock_classes)));
                goto error;
        }

        ret = bt_value_bool_get(assume_absolute_clock_classes, &bool_val);
        assert(ret == 0);
        muxer_comp->assume_absolute_clock_classes = (bool) bool_val;
        BT_LOGD("Configured muxer component: muxer-comp-addr=%p, "
                "assume-absolute-clock-classes=%d",
                muxer_comp, muxer_comp->assume_absolute_clock_classes);
        goto end;

error:
        ret = -1;

end:
        bt_put(default_params);
        bt_put(real_params);
        bt_put(assume_absolute_clock_classes);
        return ret;
}

BT_HIDDEN
enum bt_component_status muxer_init(
                struct bt_private_component *priv_comp,
                struct bt_value *params, void *init_data)
{
        int ret;
        enum bt_component_status status = BT_COMPONENT_STATUS_OK;
        struct muxer_comp *muxer_comp = g_new0(struct muxer_comp, 1);

        BT_LOGD("Initializing muxer component: "
                "comp-addr=%p, params-addr=%p", priv_comp, params);

        if (!muxer_comp) {
                BT_LOGE_STR("Failed to allocate one muxer component.");
                goto error;
        }

        ret = configure_muxer_comp(muxer_comp, params);
        if (ret) {
                BT_LOGE("Cannot configure muxer component: "
                        "muxer-comp-addr=%p, params-addr=%p",
                        muxer_comp, params);
                goto error;
        }

        muxer_comp->muxer_notif_iters = g_ptr_array_new();
        if (!muxer_comp->muxer_notif_iters) {
                BT_LOGE_STR("Failed to allocate a GPtrArray.");
                goto error;
        }

        muxer_comp->priv_comp = priv_comp;
        ret = bt_private_component_set_user_data(priv_comp, muxer_comp);
        assert(ret == 0);
        status = ensure_available_input_port(priv_comp);
        if (status != BT_COMPONENT_STATUS_OK) {
                BT_LOGE("Cannot ensure that at least one muxer component's input port is available: "
                        "muxer-comp-addr=%p, status=%s",
                        muxer_comp,
                        bt_component_status_string(status));
                goto error;
        }

        status = create_output_port(priv_comp);
        if (status) {
                BT_LOGE("Cannot create muxer component's output port: "
                        "muxer-comp-addr=%p, status=%s",
                        muxer_comp,
                        bt_component_status_string(status));
                goto error;
        }

        BT_LOGD("Initialized muxer component: "
                "comp-addr=%p, params-addr=%p, muxer-comp-addr=%p",
                priv_comp, params, muxer_comp);

        goto end;

error:
        destroy_muxer_comp(muxer_comp);
        ret = bt_private_component_set_user_data(priv_comp, NULL);
        assert(ret == 0);

        if (status == BT_COMPONENT_STATUS_OK) {
                status = BT_COMPONENT_STATUS_ERROR;
        }

end:
        return status;
}

BT_HIDDEN
void muxer_finalize(struct bt_private_component *priv_comp)
{
        struct muxer_comp *muxer_comp =
                bt_private_component_get_user_data(priv_comp);

        BT_LOGD("Finalizing muxer component: comp-addr=%p",
                priv_comp);
        destroy_muxer_comp(muxer_comp);
}

static
struct bt_notification_iterator *create_notif_iter_on_input_port(
                struct bt_private_port *priv_port, int *ret)
{
        struct bt_port *port = bt_port_from_private_port(priv_port);
        struct bt_notification_iterator *notif_iter = NULL;
        struct bt_private_connection *priv_conn = NULL;
        enum bt_connection_status conn_status;

        assert(ret);
        *ret = 0;
        assert(port);
        assert(bt_port_is_connected(port));
        priv_conn = bt_private_port_get_private_connection(priv_port);
        assert(priv_conn);

        // TODO: Advance the iterator to >= the time of the latest
        //       returned notification by the muxer notification
        //       iterator which creates it.
        conn_status = bt_private_connection_create_notification_iterator(
                priv_conn, NULL, &notif_iter);
        if (conn_status != BT_CONNECTION_STATUS_OK) {
                BT_LOGE("Cannot create upstream notification iterator on input port's connection: "
                        "port-addr=%p, port-name=\"%s\", conn-addr=%p, "
                        "status=%s",
                        port, bt_port_get_name(port), priv_conn,
                        bt_connection_status_string(conn_status));
                *ret = -1;
                goto end;
        }

        BT_LOGD("Created upstream notification iterator on input port's connection: "
                "port-addr=%p, port-name=\"%s\", conn-addr=%p, "
                "notif-iter-addr=%p",
                port, bt_port_get_name(port), priv_conn, notif_iter);

end:
        bt_put(port);
        bt_put(priv_conn);
        return notif_iter;
}

static
enum bt_notification_iterator_status muxer_upstream_notif_iter_next(
                struct muxer_upstream_notif_iter *muxer_upstream_notif_iter)
{
        enum bt_notification_iterator_status status;

        BT_LOGV("Calling upstream notification iterator's \"next\" method: "
                "muxer-upstream-notif-iter-wrap-addr=%p, notif-iter-addr=%p",
                muxer_upstream_notif_iter,
                muxer_upstream_notif_iter->notif_iter);
        status = bt_notification_iterator_next(
                muxer_upstream_notif_iter->notif_iter);
        BT_LOGV("Upstream notification iterator's \"next\" method returned: "
                "status=%s", bt_notification_iterator_status_string(status));

        switch (status) {
        case BT_NOTIFICATION_ITERATOR_STATUS_OK:
                /*
                 * Notification iterator's current notification is valid:
                 * it must be considered for muxing operations.
                 */
                BT_LOGV_STR("Validated upstream notification iterator wrapper.");
                muxer_upstream_notif_iter->is_valid = true;
                break;
        case BT_NOTIFICATION_ITERATOR_STATUS_AGAIN:
                /*
                 * Notification iterator's current notification is not
                 * valid anymore. Return
                 * BT_NOTIFICATION_ITERATOR_STATUS_AGAIN
                 * immediately.
                 */
                BT_LOGV_STR("Invalidated upstream notification iterator wrapper because of BT_NOTIFICATION_ITERATOR_STATUS_AGAIN.");
                muxer_upstream_notif_iter->is_valid = false;
                break;
        case BT_NOTIFICATION_ITERATOR_STATUS_END:       /* Fall-through. */
        case BT_NOTIFICATION_ITERATOR_STATUS_CANCELED:
                /*
                 * Notification iterator reached the end: release it. It
                 * won't be considered again to find the youngest
                 * notification.
                 */
                BT_LOGV_STR("Invalidated upstream notification iterator wrapper because of BT_NOTIFICATION_ITERATOR_STATUS_END or BT_NOTIFICATION_ITERATOR_STATUS_CANCELED.");
                BT_PUT(muxer_upstream_notif_iter->notif_iter);
                muxer_upstream_notif_iter->is_valid = false;
                status = BT_NOTIFICATION_ITERATOR_STATUS_OK;
                break;
        default:
                /* Error or unsupported status code */
                BT_LOGE("Error or unsupported status code: "
                        "status-code=%d", status);
                status = BT_NOTIFICATION_ITERATOR_STATUS_ERROR;
                break;
        }

        return status;
}

static
int muxer_notif_iter_handle_newly_connected_ports(
                struct muxer_notif_iter *muxer_notif_iter)
{
        int ret = 0;

        BT_LOGV("Handling newly connected ports: "
                "muxer-notif-iter-addr=%p", muxer_notif_iter);

        /*
         * Here we create one upstream notification iterator for each
         * 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;
                struct bt_private_port *priv_port;
                struct bt_port *port;
                struct bt_notification_iterator *upstream_notif_iter = NULL;
                struct muxer_upstream_notif_iter *muxer_upstream_notif_iter;

                if (!node) {
                        break;
                }

                priv_port = node->data;
                port = bt_port_from_private_port(priv_port);
                assert(port);

                if (!bt_port_is_connected(port)) {
                        /*
                         * Looks like this port is not connected
                         * anymore: we can't create an upstream
                         * notification iterator on its (non-existing)
                         * connection in this case.
                         */
                        goto remove_node;
                }

                BT_PUT(port);
                upstream_notif_iter = create_notif_iter_on_input_port(priv_port,
                        &ret);
                if (ret) {
                        /* create_notif_iter_on_input_port() logs errors */
                        assert(!upstream_notif_iter);
                        goto error;
                }

                muxer_upstream_notif_iter =
                        muxer_notif_iter_add_upstream_notif_iter(
                                muxer_notif_iter, upstream_notif_iter,
                                priv_port);
                BT_PUT(upstream_notif_iter);
                if (!muxer_upstream_notif_iter) {
                        /*
                         * muxer_notif_iter_add_upstream_notif_iter()
                         * logs errors.
                         */
                        goto error;
                }

remove_node:
                bt_put(upstream_notif_iter);
                bt_put(port);
                muxer_notif_iter->newly_connected_priv_ports =
                        g_list_delete_link(
                                muxer_notif_iter->newly_connected_priv_ports,
                                node);
        }

        goto end;

error:
        if (ret >= 0) {
                ret = -1;
        }

end:
        return ret;
}

static
int get_notif_ts_ns(struct muxer_comp *muxer_comp,
                struct muxer_notif_iter *muxer_notif_iter,
                struct bt_notification *notif, int64_t last_returned_ts_ns,
                int64_t *ts_ns)
{
        struct bt_clock_class_priority_map *cc_prio_map = NULL;
        struct bt_ctf_clock_class *clock_class = NULL;
        struct bt_ctf_clock_value *clock_value = NULL;
        struct bt_ctf_event *event = NULL;
        int ret = 0;
        const unsigned char *cc_uuid;
        const char *cc_name;

        assert(notif);
        assert(ts_ns);

        BT_LOGV("Getting notification's timestamp: "
                "muxer-notif-iter-addr=%p, notif-addr=%p, "
                "last-returned-ts=%" PRId64,
                muxer_notif_iter, notif, last_returned_ts_ns);

        switch (bt_notification_get_type(notif)) {
        case BT_NOTIFICATION_TYPE_EVENT:
                cc_prio_map =
                        bt_notification_event_get_clock_class_priority_map(
                                notif);
                break;

        case BT_NOTIFICATION_TYPE_INACTIVITY:
                cc_prio_map =
                        bt_notification_inactivity_get_clock_class_priority_map(
                                notif);
                break;
        default:
                /* All the other notifications have a higher priority */
                BT_LOGV_STR("Notification has no timestamp: using the last returned timestamp.");
                *ts_ns = last_returned_ts_ns;
                goto end;
        }

        if (!cc_prio_map) {
                BT_LOGE("Cannot get notification's clock class priority map: "
                        "notif-addr=%p", notif);
                goto error;
        }

        /*
         * If the clock class priority map is empty, then we consider
         * that this notification has no time. In this case it's always
         * the youngest.
         */
        if (bt_clock_class_priority_map_get_clock_class_count(cc_prio_map) == 0) {
                BT_LOGV_STR("Notification's clock class priorty map contains 0 clock classes: "
                        "using the last returned timestamp.");
                *ts_ns = last_returned_ts_ns;
                goto end;
        }

        clock_class =
                bt_clock_class_priority_map_get_highest_priority_clock_class(
                        cc_prio_map);
        if (!clock_class) {
                BT_LOGE("Cannot get the clock class with the highest priority from clock class priority map: "
                        "cc-prio-map-addr=%p", cc_prio_map);
                goto error;
        }

        cc_uuid = bt_ctf_clock_class_get_uuid(clock_class);
        cc_name = bt_ctf_clock_class_get_name(clock_class);

        if (muxer_notif_iter->clock_class_expectation ==
                        MUXER_NOTIF_ITER_CLOCK_CLASS_EXPECTATION_ANY) {
                /*
                 * This is the first clock class that this muxer
                 * notification iterator encounters. Its properties
                 * determine what to expect for the whole lifetime of
                 * the iterator without a true
                 * `assume-absolute-clock-classes` parameter.
                 */
                if (bt_ctf_clock_class_is_absolute(clock_class)) {
                        /* Expect absolute clock classes */
                        muxer_notif_iter->clock_class_expectation =
                                MUXER_NOTIF_ITER_CLOCK_CLASS_EXPECTATION_ABSOLUTE;
                } else {
                        if (cc_uuid) {
                                /*
                                 * Expect non-absolute clock classes
                                 * with a specific UUID.
                                 */
                                muxer_notif_iter->clock_class_expectation =
                                        MUXER_NOTIF_ITER_CLOCK_CLASS_EXPECTATION_NOT_ABS_SPEC_UUID;
                                memcpy(muxer_notif_iter->expected_clock_class_uuid,
                                        cc_uuid, BABELTRACE_UUID_LEN);
                        } else {
                                /*
                                 * Expect non-absolute clock classes
                                 * with no UUID.
                                 */
                                muxer_notif_iter->clock_class_expectation =
                                        MUXER_NOTIF_ITER_CLOCK_CLASS_EXPECTATION_NOT_ABS_NO_UUID;
                        }
                }
        }

        if (!muxer_comp->assume_absolute_clock_classes) {
                switch (muxer_notif_iter->clock_class_expectation) {
                case MUXER_NOTIF_ITER_CLOCK_CLASS_EXPECTATION_ABSOLUTE:
                        if (!bt_ctf_clock_class_is_absolute(clock_class)) {
                                BT_LOGE("Expecting an absolute clock class, "
                                        "but got a non-absolute one: "
                                        "clock-class-addr=%p, clock-class-name=\"%s\"",
                                        clock_class, cc_name);
                                goto error;
                        }
                        break;
                case MUXER_NOTIF_ITER_CLOCK_CLASS_EXPECTATION_NOT_ABS_NO_UUID:
                        if (bt_ctf_clock_class_is_absolute(clock_class)) {
                                BT_LOGE("Expecting a non-absolute clock class with no UUID, "
                                        "but got an absolute one: "
                                        "clock-class-addr=%p, clock-class-name=\"%s\"",
                                        clock_class, cc_name);
                                goto error;
                        }

                        if (cc_uuid) {
                                BT_LOGE("Expecting a non-absolute clock class with no UUID, "
                                        "but got one with a UUID: "
                                        "clock-class-addr=%p, clock-class-name=\"%s\", "
                                        "uuid=\"%02x%02x%02x%02x-%02x%02x-%02x%02x-%02x%02x-%02x%02x%02x%02x%02x%02x\"",
                                        clock_class, cc_name,
                                        (unsigned int) cc_uuid[0],
                                        (unsigned int) cc_uuid[1],
                                        (unsigned int) cc_uuid[2],
                                        (unsigned int) cc_uuid[3],
                                        (unsigned int) cc_uuid[4],
                                        (unsigned int) cc_uuid[5],
                                        (unsigned int) cc_uuid[6],
                                        (unsigned int) cc_uuid[7],
                                        (unsigned int) cc_uuid[8],
                                        (unsigned int) cc_uuid[9],
                                        (unsigned int) cc_uuid[10],
                                        (unsigned int) cc_uuid[11],
                                        (unsigned int) cc_uuid[12],
                                        (unsigned int) cc_uuid[13],
                                        (unsigned int) cc_uuid[14],
                                        (unsigned int) cc_uuid[15]);
                                goto error;
                        }
                        break;
                case MUXER_NOTIF_ITER_CLOCK_CLASS_EXPECTATION_NOT_ABS_SPEC_UUID:
                        if (bt_ctf_clock_class_is_absolute(clock_class)) {
                                BT_LOGE("Expecting a non-absolute clock class with a specific UUID, "
                                        "but got an absolute one: "
                                        "clock-class-addr=%p, clock-class-name=\"%s\"",
                                        clock_class, cc_name);
                                goto error;
                        }

                        if (!cc_uuid) {
                                BT_LOGE("Expecting a non-absolute clock class with a specific UUID, "
                                        "but got one with no UUID: "
                                        "clock-class-addr=%p, clock-class-name=\"%s\"",
                                        clock_class, cc_name);
                                goto error;
                        }

                        if (memcmp(muxer_notif_iter->expected_clock_class_uuid,
                                        cc_uuid, BABELTRACE_UUID_LEN) != 0) {
                                BT_LOGE("Expecting a non-absolute clock class with a specific UUID, "
                                        "but got one with different UUID: "
                                        "clock-class-addr=%p, clock-class-name=\"%s\", "
                                        "expected-uuid=\"%02x%02x%02x%02x-%02x%02x-%02x%02x-%02x%02x-%02x%02x%02x%02x%02x%02x\", "
                                        "uuid=\"%02x%02x%02x%02x-%02x%02x-%02x%02x-%02x%02x-%02x%02x%02x%02x%02x%02x\"",
                                        clock_class, cc_name,
                                        (unsigned int) muxer_notif_iter->expected_clock_class_uuid[0],
                                        (unsigned int) muxer_notif_iter->expected_clock_class_uuid[1],
                                        (unsigned int) muxer_notif_iter->expected_clock_class_uuid[2],
                                        (unsigned int) muxer_notif_iter->expected_clock_class_uuid[3],
                                        (unsigned int) muxer_notif_iter->expected_clock_class_uuid[4],
                                        (unsigned int) muxer_notif_iter->expected_clock_class_uuid[5],
                                        (unsigned int) muxer_notif_iter->expected_clock_class_uuid[6],
                                        (unsigned int) muxer_notif_iter->expected_clock_class_uuid[7],
                                        (unsigned int) muxer_notif_iter->expected_clock_class_uuid[8],
                                        (unsigned int) muxer_notif_iter->expected_clock_class_uuid[9],
                                        (unsigned int) muxer_notif_iter->expected_clock_class_uuid[10],
                                        (unsigned int) muxer_notif_iter->expected_clock_class_uuid[11],
                                        (unsigned int) muxer_notif_iter->expected_clock_class_uuid[12],
                                        (unsigned int) muxer_notif_iter->expected_clock_class_uuid[13],
                                        (unsigned int) muxer_notif_iter->expected_clock_class_uuid[14],
                                        (unsigned int) muxer_notif_iter->expected_clock_class_uuid[15],
                                        (unsigned int) cc_uuid[0],
                                        (unsigned int) cc_uuid[1],
                                        (unsigned int) cc_uuid[2],
                                        (unsigned int) cc_uuid[3],
                                        (unsigned int) cc_uuid[4],
                                        (unsigned int) cc_uuid[5],
                                        (unsigned int) cc_uuid[6],
                                        (unsigned int) cc_uuid[7],
                                        (unsigned int) cc_uuid[8],
                                        (unsigned int) cc_uuid[9],
                                        (unsigned int) cc_uuid[10],
                                        (unsigned int) cc_uuid[11],
                                        (unsigned int) cc_uuid[12],
                                        (unsigned int) cc_uuid[13],
                                        (unsigned int) cc_uuid[14],
                                        (unsigned int) cc_uuid[15]);
                                goto error;
                        }
                        break;
                default:
                        /* Unexpected */
                        BT_LOGF("Unexpected clock class expectation: "
                                "expectation-code=%d",
                                muxer_notif_iter->clock_class_expectation);
                        abort();
                }
        }

        switch (bt_notification_get_type(notif)) {
        case BT_NOTIFICATION_TYPE_EVENT:
                event = bt_notification_event_get_event(notif);
                assert(event);
                clock_value = bt_ctf_event_get_clock_value(event,
                        clock_class);
                break;
        case BT_NOTIFICATION_TYPE_INACTIVITY:
                clock_value = bt_notification_inactivity_get_clock_value(
                        notif, clock_class);
                break;
        default:
                BT_LOGF("Unexpected notification type at this point: "
                        "type=%d", bt_notification_get_type(notif));
                abort();
        }

        if (!clock_value) {
                BT_LOGE("Cannot get notification's clock value for clock class: "
                        "clock-class-addr=%p, clock-class-name=\"%s\"",
                        clock_class, cc_name);
                goto error;
        }

        ret = bt_ctf_clock_value_get_value_ns_from_epoch(clock_value, ts_ns);
        if (ret) {
                BT_LOGE("Cannot get nanoseconds from Epoch of clock value: "
                        "clock-value-addr=%p", clock_value);
                goto error;
        }

        goto end;

error:
        ret = -1;

end:
        if (ret == 0) {
                BT_LOGV("Found notification's timestamp: "
                        "muxer-notif-iter-addr=%p, notif-addr=%p, "
                        "last-returned-ts=%" PRId64 ", ts=%" PRId64,
                        muxer_notif_iter, notif, last_returned_ts_ns,
                        *ts_ns);
        }

        bt_put(cc_prio_map);
        bt_put(event);
        bt_put(clock_class);
        bt_put(clock_value);
        return ret;
}

/*
 * This function finds the youngest available notification amongst the
 * non-ended upstream notification iterators and returns the upstream
 * notification iterator which has it, or
 * BT_NOTIFICATION_ITERATOR_STATUS_END if there's no available
 * notification.
 *
 * This function does NOT:
 *
 * * Update any upstream notification iterator.
 * * Check for newly connected ports.
 * * Check the upstream notification iterators to retry.
 *
 * On sucess, this function sets *muxer_upstream_notif_iter to the
 * upstream notification iterator of which the current notification is
 * the youngest, and sets *ts_ns to its time.
 */
static
enum bt_notification_iterator_status
muxer_notif_iter_youngest_upstream_notif_iter(
                struct muxer_comp *muxer_comp,
                struct muxer_notif_iter *muxer_notif_iter,
                struct muxer_upstream_notif_iter **muxer_upstream_notif_iter,
                int64_t *ts_ns)
{
        size_t i;
        int ret;
        int64_t youngest_ts_ns = INT64_MAX;
        enum bt_notification_iterator_status status =
                BT_NOTIFICATION_ITERATOR_STATUS_OK;

        assert(muxer_comp);
        assert(muxer_notif_iter);
        assert(muxer_upstream_notif_iter);
        *muxer_upstream_notif_iter = NULL;

        for (i = 0; i < muxer_notif_iter->muxer_upstream_notif_iters->len; i++) {
                struct bt_notification *notif;
                struct muxer_upstream_notif_iter *cur_muxer_upstream_notif_iter =
                        g_ptr_array_index(muxer_notif_iter->muxer_upstream_notif_iters, i);
                int64_t notif_ts_ns;

                if (!cur_muxer_upstream_notif_iter->notif_iter) {
                        /* This upstream notification iterator is ended */
                        BT_LOGV("Skipping ended upstream notification iterator: "
                                "muxer-upstream-notif-iter-wrap-addr=%p",
                                cur_muxer_upstream_notif_iter);
                        continue;
                }

                assert(cur_muxer_upstream_notif_iter->is_valid);
                notif = bt_notification_iterator_get_notification(
                        cur_muxer_upstream_notif_iter->notif_iter);
                assert(notif);
                ret = get_notif_ts_ns(muxer_comp, muxer_notif_iter, notif,
                        muxer_notif_iter->last_returned_ts_ns, &notif_ts_ns);
                bt_put(notif);
                if (ret) {
                        /* get_notif_ts_ns() logs errors */
                        *muxer_upstream_notif_iter = NULL;
                        status = BT_NOTIFICATION_ITERATOR_STATUS_ERROR;
                        goto end;
                }

                if (notif_ts_ns <= youngest_ts_ns) {
                        *muxer_upstream_notif_iter =
                                cur_muxer_upstream_notif_iter;
                        youngest_ts_ns = notif_ts_ns;
                        *ts_ns = youngest_ts_ns;
                }
        }

        if (!*muxer_upstream_notif_iter) {
                status = BT_NOTIFICATION_ITERATOR_STATUS_END;
                *ts_ns = INT64_MIN;
        }

end:
        return status;
}

static
enum bt_notification_iterator_status validate_muxer_upstream_notif_iter(
        struct muxer_upstream_notif_iter *muxer_upstream_notif_iter)
{
        enum bt_notification_iterator_status status =
                BT_NOTIFICATION_ITERATOR_STATUS_OK;

        BT_LOGV("Validating muxer's upstream notification iterator wrapper: "
                "muxer-upstream-notif-iter-wrap-addr=%p",
                muxer_upstream_notif_iter);

        if (muxer_upstream_notif_iter->is_valid ||
                        !muxer_upstream_notif_iter->notif_iter) {
                goto end;
        }

        /* muxer_upstream_notif_iter_next() logs details/errors */
        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;

        BT_LOGV("Validating muxer's upstream notification iterator wrappers: "
                "muxer-notif-iter-addr=%p", muxer_notif_iter);

        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) {
                        if (status < 0) {
                                BT_LOGE("Cannot validate muxer's upstream notification iterator wrapper: "
                                        "muxer-notif-iter-addr=%p, "
                                        "muxer-upstream-notif-iter-wrap-addr=%p",
                                        muxer_notif_iter,
                                        muxer_upstream_notif_iter);
                        } else {
                                BT_LOGV("Cannot validate muxer's upstream notification iterator wrapper: "
                                        "muxer-notif-iter-addr=%p, "
                                        "muxer-upstream-notif-iter-wrap-addr=%p",
                                        muxer_notif_iter,
                                        muxer_upstream_notif_iter);
                        }

                        goto end;
                }

                /*
                 * Remove this muxer upstream notification iterator
                 * if it's ended or canceled.
                 */
                if (!muxer_upstream_notif_iter->notif_iter) {
                        /*
                         * Use g_ptr_array_remove_fast() because the
                         * order of those elements is not important.
                         */
                        BT_LOGV("Removing muxer's upstream notification iterator wrapper: ended or canceled: "
                                "muxer-notif-iter-addr=%p, "
                                "muxer-upstream-notif-iter-wrap-addr=%p",
                                muxer_notif_iter, muxer_upstream_notif_iter);
                        g_ptr_array_remove_index_fast(
                                muxer_notif_iter->muxer_upstream_notif_iters,
                                i);
                        i--;
                }
        }

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) {
                        BT_LOGE("Cannot handle newly connected input ports for muxer's notification iterator: "
                                "muxer-comp-addr=%p, muxer-notif-iter-addr=%p, "
                                "ret=%d",
                                muxer_comp, muxer_notif_iter, 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) {
                        /* validate_muxer_upstream_notif_iters() logs details */
                        goto end;
                }

                /*
                 * 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.
                 */
                if (!muxer_notif_iter->newly_connected_priv_ports) {
                        BT_LOGV("Not breaking this loop: muxer's notification iterator still has newly connected input ports to handle: "
                                "muxer-comp-addr=%p", muxer_comp);
                        break;
                }
        }

        assert(!muxer_notif_iter->newly_connected_priv_ports);

        /*
         * 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.
         */
        next_return.status =
                muxer_notif_iter_youngest_upstream_notif_iter(muxer_comp,
                        muxer_notif_iter, &muxer_upstream_notif_iter,
                        &next_return_ts);
        if (next_return.status < 0 ||
                        next_return.status == BT_NOTIFICATION_ITERATOR_STATUS_END ||
                        next_return.status == BT_NOTIFICATION_ITERATOR_STATUS_CANCELED) {
                if (next_return.status < 0) {
                        BT_LOGE("Cannot find the youngest upstream notification iterator wrapper: "
                                "status=%s",
                                bt_notification_iterator_status_string(next_return.status));
                } else {
                        BT_LOGV("Cannot find the youngest upstream notification iterator wrapper: "
                                "status=%s",
                                bt_notification_iterator_status_string(next_return.status));
                }

                goto end;
        }

        if (next_return_ts < muxer_notif_iter->last_returned_ts_ns) {
                BT_LOGE("Youngest upstream notification iterator wrapper's timestamp is less than muxer's notification iterator's last returned timestamp: "
                        "muxer-notif-iter-addr=%p, ts=%" PRId64 ", "
                        "last-returned-ts=%" PRId64,
                        muxer_notif_iter, next_return_ts,
                        muxer_notif_iter->last_returned_ts_ns);
                next_return.status = BT_NOTIFICATION_ITERATOR_STATUS_ERROR;
                goto end;
        }

        BT_LOGV("Found youngest upstream notification iterator wrapper: "
                "muxer-notif-iter-addr=%p, "
                "muxer-upstream-notif-iter-wrap-addr=%p, "
                "ts=%" PRId64,
                muxer_notif_iter, muxer_upstream_notif_iter, next_return_ts);
        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 invalidate the upstream notification iterator so that, the
         * next time this function is called,
         * validate_muxer_upstream_notif_iters() will make it valid.
         */
        muxer_upstream_notif_iter->is_valid = false;
        muxer_notif_iter->last_returned_ts_ns = next_return_ts;

end:
        return next_return;
}

static
void destroy_muxer_notif_iter(struct muxer_notif_iter *muxer_notif_iter)
{
        if (!muxer_notif_iter) {
                return;
        }

        BT_LOGD("Destroying muxer component's notification iterator: "
                "muxer-notif-iter-addr=%p", muxer_notif_iter);

        if (muxer_notif_iter->muxer_upstream_notif_iters) {
                BT_LOGD_STR("Destroying muxer's upstream notification iterator wrappers.");
                g_ptr_array_free(
                        muxer_notif_iter->muxer_upstream_notif_iters, TRUE);
        }

        g_list_free(muxer_notif_iter->newly_connected_priv_ports);
        g_free(muxer_notif_iter);
}

static
int muxer_notif_iter_init_newly_connected_ports(struct muxer_comp *muxer_comp,
                struct muxer_notif_iter *muxer_notif_iter)
{
        struct bt_component *comp;
        int64_t count;
        int64_t i;
        int ret = 0;

        /*
         * Add the connected input ports to this muxer notification
         * iterator's list of newly connected ports. They will be
         * handled by muxer_notif_iter_handle_newly_connected_ports().
         */
        comp = bt_component_from_private_component(muxer_comp->priv_comp);
        assert(comp);
        count = bt_component_filter_get_input_port_count(comp);
        if (count < 0) {
                BT_LOGD("No input port to initialize for muxer component's notification iterator: "
                        "muxer-comp-addr=%p, muxer-notif-iter-addr=%p",
                        muxer_comp, muxer_notif_iter);
                goto end;
        }

        for (i = 0; i < count; i++) {
                struct bt_private_port *priv_port =
                        bt_private_component_filter_get_input_private_port_by_index(
                                muxer_comp->priv_comp, i);
                struct bt_port *port;

                assert(priv_port);
                port = bt_port_from_private_port(priv_port);
                assert(port);

                if (!bt_port_is_connected(port)) {
                        BT_LOGD("Skipping input port: not connected: "
                                "muxer-comp-addr=%p, port-addr=%p, port-name\"%s\"",
                                muxer_comp, port, bt_port_get_name(port));
                        bt_put(priv_port);
                        bt_put(port);
                        continue;
                }

                bt_put(port);
                bt_put(priv_port);
                muxer_notif_iter->newly_connected_priv_ports =
                        g_list_append(
                                muxer_notif_iter->newly_connected_priv_ports,
                                priv_port);
                if (!muxer_notif_iter->newly_connected_priv_ports) {
                        BT_LOGE("Cannot append port to muxer's notification iterator list of newly connected input ports: "
                                "port-addr=%p, port-name=\"%s\", "
                                "muxer-notif-iter-addr=%p", port,
                                bt_port_get_name(port), muxer_notif_iter);
                        ret = -1;
                        goto end;
                }

                BT_LOGD("Appended port to muxer's notification iterator list of newly connected input ports: "
                        "port-addr=%p, port-name=\"%s\", "
                        "muxer-notif-iter-addr=%p", port,
                        bt_port_get_name(port), muxer_notif_iter);
        }

end:
        bt_put(comp);
        return ret;
}

BT_HIDDEN
enum bt_notification_iterator_status muxer_notif_iter_init(
                struct bt_private_notification_iterator *priv_notif_iter,
                struct bt_private_port *output_priv_port)
{
        struct muxer_comp *muxer_comp = NULL;
        struct muxer_notif_iter *muxer_notif_iter = NULL;
        struct bt_private_component *priv_comp = NULL;
        enum bt_notification_iterator_status status =
                BT_NOTIFICATION_ITERATOR_STATUS_OK;
        int ret;

        priv_comp = bt_private_notification_iterator_get_private_component(
                priv_notif_iter);
        assert(priv_comp);
        muxer_comp = bt_private_component_get_user_data(priv_comp);
        assert(muxer_comp);
        BT_LOGD("Initializing muxer component's notification iterator: "
                "comp-addr=%p, muxer-comp-addr=%p, notif-iter-addr=%p",
                priv_comp, muxer_comp, priv_notif_iter);

        if (muxer_comp->initializing_muxer_notif_iter) {
                /*
                 * Weird, unhandled situation detected: downstream
                 * creates a muxer notification iterator while creating
                 * another muxer notification iterator (same component).
                 */
                BT_LOGE("Recursive initialization of muxer component's notification iterator: "
                        "comp-addr=%p, muxer-comp-addr=%p, notif-iter-addr=%p",
                        priv_comp, muxer_comp, priv_notif_iter);
                goto error;
        }

        muxer_comp->initializing_muxer_notif_iter = true;
        muxer_notif_iter = g_new0(struct muxer_notif_iter, 1);
        if (!muxer_notif_iter) {
                BT_LOGE_STR("Failed to allocate one muxer component's notification iterator.");
                goto error;
        }

        muxer_notif_iter->last_returned_ts_ns = INT64_MIN;
        muxer_notif_iter->muxer_upstream_notif_iters =
                g_ptr_array_new_with_free_func(
                        (GDestroyNotify) destroy_muxer_upstream_notif_iter);
        if (!muxer_notif_iter->muxer_upstream_notif_iters) {
                BT_LOGE_STR("Failed to allocate a GPtrArray.");
                goto error;
        }

        /*
         * Add the muxer notification iterator to the component's array
         * of muxer notification iterators here because
         * muxer_notif_iter_init_newly_connected_ports() can cause
         * muxer_port_connected() to be called, which adds the newly
         * connected port to each muxer notification iterator's list of
         * newly connected ports.
         */
        g_ptr_array_add(muxer_comp->muxer_notif_iters, muxer_notif_iter);
        ret = muxer_notif_iter_init_newly_connected_ports(muxer_comp,
                muxer_notif_iter);
        if (ret) {
                BT_LOGE("Cannot initialize newly connected input ports for muxer component's notification iterator: "
                        "comp-addr=%p, muxer-comp-addr=%p, "
                        "muxer-notif-iter-addr=%p, notif-iter-addr=%p, ret=%d",
                        priv_comp, muxer_comp, muxer_notif_iter,
                        priv_notif_iter, ret);
                goto error;
        }

        ret = bt_private_notification_iterator_set_user_data(priv_notif_iter,
                muxer_notif_iter);
        assert(ret == 0);
        BT_LOGD("Initialized muxer component's notification iterator: "
                "comp-addr=%p, muxer-comp-addr=%p, muxer-notif-iter-addr=%p, "
                "notif-iter-addr=%p",
                priv_comp, muxer_comp, muxer_notif_iter, priv_notif_iter);
        goto end;

error:
        if (g_ptr_array_index(muxer_comp->muxer_notif_iters,
                        muxer_comp->muxer_notif_iters->len - 1) == muxer_notif_iter) {
                g_ptr_array_remove_index(muxer_comp->muxer_notif_iters,
                        muxer_comp->muxer_notif_iters->len - 1);
        }

        destroy_muxer_notif_iter(muxer_notif_iter);
        ret = bt_private_notification_iterator_set_user_data(priv_notif_iter,
                NULL);
        assert(ret == 0);
        status = BT_NOTIFICATION_ITERATOR_STATUS_ERROR;

end:
        muxer_comp->initializing_muxer_notif_iter = false;
        bt_put(priv_comp);
        return status;
}

BT_HIDDEN
void muxer_notif_iter_finalize(
                struct bt_private_notification_iterator *priv_notif_iter)
{
        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;

        priv_comp = bt_private_notification_iterator_get_private_component(
                priv_notif_iter);
        assert(priv_comp);
        muxer_comp = bt_private_component_get_user_data(priv_comp);
        BT_LOGD("Finalizing muxer component's notification iterator: "
                "comp-addr=%p, muxer-comp-addr=%p, muxer-notif-iter-addr=%p, "
                "notif-iter-addr=%p",
                priv_comp, muxer_comp, muxer_notif_iter, priv_notif_iter);

        if (muxer_comp) {
                (void) g_ptr_array_remove_fast(muxer_comp->muxer_notif_iters,
                        muxer_notif_iter);
                destroy_muxer_notif_iter(muxer_notif_iter);
        }

        bt_put(priv_comp);
}

BT_HIDDEN
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;
        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;

        assert(muxer_notif_iter);
        priv_comp = bt_private_notification_iterator_get_private_component(
                priv_notif_iter);
        assert(priv_comp);
        muxer_comp = bt_private_component_get_user_data(priv_comp);
        assert(muxer_comp);

        BT_LOGV("Muxer component's notification iterator's \"next\" method called: "
                "comp-addr=%p, muxer-comp-addr=%p, muxer-notif-iter-addr=%p, "
                "notif-iter-addr=%p",
                priv_comp, muxer_comp, muxer_notif_iter, priv_notif_iter);

        /* Are we in an error state set elsewhere? */
        if (unlikely(muxer_comp->error)) {
                BT_LOGE("Muxer component is already in an error state: returning BT_NOTIFICATION_ITERATOR_STATUS_ERROR: "
                        "comp-addr=%p, muxer-comp-addr=%p, muxer-notif-iter-addr=%p, "
                        "notif-iter-addr=%p",
                        priv_comp, muxer_comp, muxer_notif_iter, priv_notif_iter);
                next_ret.notification = NULL;
                next_ret.status = BT_NOTIFICATION_ITERATOR_STATUS_ERROR;
                goto end;
        }

        next_ret = muxer_notif_iter_do_next(muxer_comp, muxer_notif_iter);
        if (next_ret.status < 0) {
                BT_LOGE("Cannot get next notification: "
                        "comp-addr=%p, muxer-comp-addr=%p, muxer-notif-iter-addr=%p, "
                        "notif-iter-addr=%p, status=%s",
                        priv_comp, muxer_comp, muxer_notif_iter, priv_notif_iter,
                        bt_notification_iterator_status_string(next_ret.status));
        } else {
                BT_LOGV("Returning from muxer component's notification iterator's \"next\" method: "
                        "status=%s, notif-addr=%p",
                        bt_notification_iterator_status_string(next_ret.status),
                        next_ret.notification);
        }

end:
        bt_put(priv_comp);
        return next_ret;
}

BT_HIDDEN
void muxer_port_connected(
                struct bt_private_component *priv_comp,
                struct bt_private_port *self_private_port,
                struct bt_port *other_port)
{
        struct bt_port *self_port =
                bt_port_from_private_port(self_private_port);
        struct muxer_comp *muxer_comp =
                bt_private_component_get_user_data(priv_comp);
        size_t i;
        int ret;

        assert(self_port);
        assert(muxer_comp);
        BT_LOGD("Port connected: "
                "comp-addr=%p, muxer-comp-addr=%p, "
                "port-addr=%p, port-name=\"%s\", "
                "other-port-addr=%p, other-port-name=\"%s\"",
                priv_comp, muxer_comp, self_port, bt_port_get_name(self_port),
                other_port, bt_port_get_name(other_port));

        if (bt_port_get_type(self_port) == BT_PORT_TYPE_OUTPUT) {
                goto end;
        }

        for (i = 0; i < muxer_comp->muxer_notif_iters->len; i++) {
                struct muxer_notif_iter *muxer_notif_iter =
                        g_ptr_array_index(muxer_comp->muxer_notif_iters, i);

                /*
                 * Add this port to the list of newly connected ports
                 * for this muxer notification iterator. We append at
                 * the end of this list while
                 * muxer_notif_iter_handle_newly_connected_ports()
                 * removes the nodes from the beginning.
                 */
                muxer_notif_iter->newly_connected_priv_ports =
                        g_list_append(
                                muxer_notif_iter->newly_connected_priv_ports,
                                self_private_port);
                if (!muxer_notif_iter->newly_connected_priv_ports) {
                        BT_LOGE("Cannot append port to muxer's notification iterator list of newly connected input ports: "
                                "port-addr=%p, port-name=\"%s\", "
                                "muxer-notif-iter-addr=%p", self_port,
                                bt_port_get_name(self_port), muxer_notif_iter);
                        muxer_comp->error = true;
                        goto end;
                }

                BT_LOGD("Appended port to muxer's notification iterator list of newly connected input ports: "
                        "port-addr=%p, port-name=\"%s\", "
                        "muxer-notif-iter-addr=%p", self_port,
                        bt_port_get_name(self_port), muxer_notif_iter);
        }

        /* One less available input port */
        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.
                 */
                BT_LOGE("Cannot ensure that at least one muxer component's input port is available: "
                        "muxer-comp-addr=%p, status=%s",
                        muxer_comp, bt_component_status_string(ret));
                muxer_comp->error = true;
                goto end;
        }

end:
        bt_put(self_port);
}

BT_HIDDEN
void muxer_port_disconnected(struct bt_private_component *priv_comp,
                struct bt_private_port *priv_port)
{
        struct bt_port *port = bt_port_from_private_port(priv_port);
        struct muxer_comp *muxer_comp =
                bt_private_component_get_user_data(priv_comp);

        assert(port);
        assert(muxer_comp);
        BT_LOGD("Port disconnected: "
                "comp-addr=%p, muxer-comp-addr=%p, port-addr=%p, "
                "port-name=\"%s\"", priv_comp, muxer_comp,
                port, bt_port_get_name(port));

        /*
         * There's nothing special to do when a port is disconnected
         * because this component deals with upstream notification
         * 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, 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 */
                muxer_comp->available_input_ports++;
                BT_LOGD("Leaving disconnected input port available for future connections: "
                        "comp-addr=%p, muxer-comp-addr=%p, port-addr=%p, "
                        "port-name=\"%s\", avail-input-port-count=%zu",
                        priv_comp, muxer_comp, port, bt_port_get_name(port),
                        muxer_comp->available_input_ports);
        }

        bt_put(port);
}