gst-plugins-rs/utils/fallbackswitch/tests/fallbackswitch.rs
Jan Schmidt bd2ff494c7 fallbackswitch: Replace with priorityswitch
fallbackswitch now supports multiple sink pads, and on a timeout of the
active pad, it will automatically switch to the next lowest priority pad
that has data available.

fallbackswitch sink pads follow the `sink_%u` template and have
`priority` as a pad property.

Co-authored-by: Vivia Nikolaidou <vivia.nikolaidou@ltnglobal.com>
2022-04-05 18:52:31 +03:00

748 lines
23 KiB
Rust

// Copyright (C) 2019 Sebastian Dröge <sebastian@centricular.com>
// Copyright (C) 2021 Jan Schmidt <jan@centricular.com>
//
// This Source Code Form is subject to the terms of the Mozilla Public License, v2.0.
// If a copy of the MPL was not distributed with this file, You can obtain one at
// <https://mozilla.org/MPL/2.0/>.
//
// SPDX-License-Identifier: MPL-2.0
use gst::debug;
use gst::prelude::*;
use once_cell::sync::Lazy;
const LATENCY: gst::ClockTime = gst::ClockTime::from_mseconds(10);
static TEST_CAT: Lazy<gst::DebugCategory> = Lazy::new(|| {
gst::DebugCategory::new(
"fallbackswitch-test",
gst::DebugColorFlags::empty(),
Some("fallbackswitch test"),
)
});
fn init() {
use std::sync::Once;
static INIT: Once = Once::new();
INIT.call_once(|| {
gst::init().unwrap();
gstfallbackswitch::plugin_register_static().expect("gstfallbackswitch test");
});
}
macro_rules! assert_fallback_buffer {
($buffer:expr, $ts:expr) => {
assert_eq!($buffer.pts(), $ts);
assert_eq!($buffer.size(), 160 * 120 * 4);
};
}
macro_rules! assert_buffer {
($buffer:expr, $ts:expr) => {
assert_eq!($buffer.pts(), $ts);
assert_eq!($buffer.size(), 320 * 240 * 4);
};
}
#[test]
fn test_no_fallback_no_drops() {
let pipeline = setup_pipeline(None, None, None);
push_buffer(&pipeline, gst::ClockTime::ZERO);
set_time(&pipeline, gst::ClockTime::ZERO + LATENCY);
let buffer = pull_buffer(&pipeline);
assert_buffer!(buffer, Some(gst::ClockTime::ZERO));
push_buffer(&pipeline, gst::ClockTime::SECOND);
set_time(&pipeline, gst::ClockTime::SECOND + LATENCY);
let buffer = pull_buffer(&pipeline);
assert_buffer!(buffer, Some(gst::ClockTime::SECOND));
push_buffer(&pipeline, 2 * gst::ClockTime::SECOND);
set_time(&pipeline, 2 * gst::ClockTime::SECOND + LATENCY);
let buffer = pull_buffer(&pipeline);
assert_buffer!(buffer, Some(2 * gst::ClockTime::SECOND));
push_eos(&pipeline);
wait_eos(&pipeline);
stop_pipeline(pipeline);
}
#[test]
fn test_no_drops_live() {
test_no_drops(true);
}
#[test]
fn test_no_drops_not_live() {
test_no_drops(false);
}
fn test_no_drops(live: bool) {
let pipeline = setup_pipeline(Some(live), None, None);
push_buffer(&pipeline, gst::ClockTime::ZERO);
push_fallback_buffer(&pipeline, gst::ClockTime::ZERO);
set_time(&pipeline, gst::ClockTime::ZERO + LATENCY);
let buffer = pull_buffer(&pipeline);
assert_buffer!(buffer, Some(gst::ClockTime::ZERO));
push_fallback_buffer(&pipeline, gst::ClockTime::SECOND);
push_buffer(&pipeline, gst::ClockTime::SECOND);
set_time(&pipeline, gst::ClockTime::SECOND + LATENCY);
let buffer = pull_buffer(&pipeline);
assert_buffer!(buffer, Some(gst::ClockTime::SECOND));
push_buffer(&pipeline, 2 * gst::ClockTime::SECOND);
push_fallback_buffer(&pipeline, 2 * gst::ClockTime::SECOND);
set_time(&pipeline, 2 * gst::ClockTime::SECOND + LATENCY);
let buffer = pull_buffer(&pipeline);
assert_buffer!(buffer, Some(2 * gst::ClockTime::SECOND));
// EOS on the fallback should not be required
push_eos(&pipeline);
wait_eos(&pipeline);
stop_pipeline(pipeline);
}
#[test]
fn test_no_drops_but_no_fallback_frames_live() {
test_no_drops_but_no_fallback_frames(true);
}
#[test]
fn test_no_drops_but_no_fallback_frames_not_live() {
test_no_drops_but_no_fallback_frames(false);
}
fn test_no_drops_but_no_fallback_frames(live: bool) {
let pipeline = setup_pipeline(Some(live), None, None);
push_buffer(&pipeline, gst::ClockTime::ZERO);
// +10ms needed here because the immediate timeout will be always at running time 0, but
// aggregator also adds the latency to it so we end up at 10ms instead.
set_time(&pipeline, LATENCY);
let buffer = pull_buffer(&pipeline);
assert_buffer!(buffer, Some(gst::ClockTime::ZERO));
push_buffer(&pipeline, gst::ClockTime::SECOND);
set_time(&pipeline, gst::ClockTime::SECOND + LATENCY);
let buffer = pull_buffer(&pipeline);
assert_buffer!(buffer, Some(gst::ClockTime::SECOND));
push_buffer(&pipeline, 2 * gst::ClockTime::SECOND);
set_time(&pipeline, 2 * gst::ClockTime::SECOND + LATENCY);
let buffer = pull_buffer(&pipeline);
assert_buffer!(buffer, Some(2 * gst::ClockTime::SECOND));
// EOS on the fallback should not be required
push_eos(&pipeline);
wait_eos(&pipeline);
stop_pipeline(pipeline);
}
#[test]
fn test_short_drop_live() {
test_short_drop(true);
}
#[test]
fn test_short_drop_not_live() {
test_short_drop(false);
}
fn test_short_drop(live: bool) {
let pipeline = setup_pipeline(Some(live), None, None);
push_buffer(&pipeline, gst::ClockTime::ZERO);
push_fallback_buffer(&pipeline, gst::ClockTime::ZERO);
set_time(&pipeline, gst::ClockTime::ZERO + LATENCY);
let buffer = pull_buffer(&pipeline);
assert_buffer!(buffer, Some(gst::ClockTime::ZERO));
// A timeout at 1s will get rid of the fallback buffer
// but not output anything
push_fallback_buffer(&pipeline, gst::ClockTime::SECOND);
// Time out the fallback buffer at +10ms
set_time(
&pipeline,
gst::ClockTime::SECOND + 10 * gst::ClockTime::MSECOND,
);
push_fallback_buffer(&pipeline, 2 * gst::ClockTime::SECOND);
push_buffer(&pipeline, 2 * gst::ClockTime::SECOND);
set_time(&pipeline, 2 * gst::ClockTime::SECOND + LATENCY);
let buffer = pull_buffer(&pipeline);
assert_buffer!(buffer, Some(2 * gst::ClockTime::SECOND));
push_eos(&pipeline);
push_fallback_eos(&pipeline);
wait_eos(&pipeline);
stop_pipeline(pipeline);
}
#[test]
fn test_long_drop_and_eos_live() {
test_long_drop_and_eos(true);
}
#[test]
fn test_long_drop_and_eos_not_live() {
test_long_drop_and_eos(false);
}
fn test_long_drop_and_eos(live: bool) {
let pipeline = setup_pipeline(Some(live), None, None);
// Produce the first frame
push_buffer(&pipeline, gst::ClockTime::ZERO);
push_fallback_buffer(&pipeline, gst::ClockTime::ZERO);
set_time(&pipeline, gst::ClockTime::ZERO);
let buffer = pull_buffer(&pipeline);
assert_buffer!(buffer, Some(gst::ClockTime::ZERO));
// Produce a second frame but only from the fallback source
push_fallback_buffer(&pipeline, gst::ClockTime::SECOND);
set_time(
&pipeline,
gst::ClockTime::SECOND + 10 * gst::ClockTime::MSECOND,
);
// Produce a third frame but only from the fallback source
push_fallback_buffer(&pipeline, 2 * gst::ClockTime::SECOND);
set_time(
&pipeline,
2 * gst::ClockTime::SECOND + 10 * gst::ClockTime::MSECOND,
);
// Produce a fourth frame but only from the fallback source
// This should be output now
push_fallback_buffer(&pipeline, 3 * gst::ClockTime::SECOND);
set_time(
&pipeline,
3 * gst::ClockTime::SECOND + 10 * gst::ClockTime::MSECOND,
);
let buffer = pull_buffer(&pipeline);
assert_fallback_buffer!(buffer, Some(3 * gst::ClockTime::SECOND));
// Produce a fifth frame but only from the fallback source
// This should be output now
push_fallback_buffer(&pipeline, 4 * gst::ClockTime::SECOND);
set_time(
&pipeline,
4 * gst::ClockTime::SECOND + 10 * gst::ClockTime::MSECOND,
);
let buffer = pull_buffer(&pipeline);
assert_fallback_buffer!(buffer, Some(4 * gst::ClockTime::SECOND));
// Wait for EOS to arrive at appsink
push_eos(&pipeline);
push_fallback_eos(&pipeline);
wait_eos(&pipeline);
stop_pipeline(pipeline);
}
#[test]
fn test_long_drop_and_recover_live() {
test_long_drop_and_recover(true);
}
#[test]
fn test_long_drop_and_recover_not_live() {
test_long_drop_and_recover(false);
}
fn test_long_drop_and_recover(live: bool) {
let pipeline = setup_pipeline(Some(live), None, None);
let switch = pipeline.by_name("switch").unwrap();
let mainsink = switch.static_pad("sink_0").unwrap();
// Produce the first frame
push_buffer(&pipeline, gst::ClockTime::ZERO);
push_fallback_buffer(&pipeline, gst::ClockTime::ZERO);
set_time(&pipeline, gst::ClockTime::ZERO);
let buffer = pull_buffer(&pipeline);
assert_buffer!(buffer, Some(gst::ClockTime::ZERO));
assert!(mainsink.property::<bool>("is-healthy"));
// Produce a second frame but only from the fallback source
push_fallback_buffer(&pipeline, gst::ClockTime::SECOND);
set_time(
&pipeline,
gst::ClockTime::SECOND + 10 * gst::ClockTime::MSECOND,
);
// Produce a third frame but only from the fallback source
push_fallback_buffer(&pipeline, 2 * gst::ClockTime::SECOND);
set_time(
&pipeline,
2 * gst::ClockTime::SECOND + 10 * gst::ClockTime::MSECOND,
);
// Produce a fourth frame but only from the fallback source
// This should be output now
push_fallback_buffer(&pipeline, 3 * gst::ClockTime::SECOND);
set_time(
&pipeline,
3 * gst::ClockTime::SECOND + 10 * gst::ClockTime::MSECOND,
);
let buffer = pull_buffer(&pipeline);
assert_fallback_buffer!(buffer, Some(3 * gst::ClockTime::SECOND));
// Produce a fifth frame but only from the fallback source
// This should be output now
push_fallback_buffer(&pipeline, 4 * gst::ClockTime::SECOND);
set_time(
&pipeline,
4 * gst::ClockTime::SECOND + 10 * gst::ClockTime::MSECOND,
);
let buffer = pull_buffer(&pipeline);
assert_fallback_buffer!(buffer, Some(4 * gst::ClockTime::SECOND));
// Produce a sixth frame from the normal source
push_buffer(&pipeline, 5 * gst::ClockTime::SECOND);
set_time(
&pipeline,
5 * gst::ClockTime::SECOND + 10 * gst::ClockTime::MSECOND,
);
let buffer = pull_buffer(&pipeline);
assert_buffer!(buffer, Some(5 * gst::ClockTime::SECOND));
assert!(!mainsink.property::<bool>("is-healthy"));
drop(mainsink);
drop(switch);
// Produce a seventh frame from the normal source but no fallback.
// This should still be output immediately
push_buffer(&pipeline, 6 * gst::ClockTime::SECOND);
set_time(
&pipeline,
6 * gst::ClockTime::SECOND + 10 * gst::ClockTime::MSECOND,
);
let buffer = pull_buffer(&pipeline);
assert_buffer!(buffer, Some(6 * gst::ClockTime::SECOND));
// Produce a eight frame from the normal source
push_buffer(&pipeline, 7 * gst::ClockTime::SECOND);
push_fallback_buffer(&pipeline, 7 * gst::ClockTime::SECOND);
set_time(
&pipeline,
7 * gst::ClockTime::SECOND + 10 * gst::ClockTime::MSECOND,
);
let buffer = pull_buffer(&pipeline);
assert_buffer!(buffer, Some(7 * gst::ClockTime::SECOND));
// Wait for EOS to arrive at appsink
push_eos(&pipeline);
push_fallback_eos(&pipeline);
wait_eos(&pipeline);
stop_pipeline(pipeline);
}
#[test]
fn test_initial_timeout_live() {
test_initial_timeout(true);
}
#[test]
fn test_initial_timeout_not_live() {
test_initial_timeout(false);
}
fn test_initial_timeout(live: bool) {
let pipeline = setup_pipeline(Some(live), None, None);
// Produce the first frame but only from the fallback source
push_fallback_buffer(&pipeline, gst::ClockTime::ZERO);
set_time(&pipeline, gst::ClockTime::ZERO);
// Produce a second frame but only from the fallback source
push_fallback_buffer(&pipeline, gst::ClockTime::SECOND);
set_time(
&pipeline,
gst::ClockTime::SECOND + 10 * gst::ClockTime::MSECOND,
);
// Produce a third frame but only from the fallback source
push_fallback_buffer(&pipeline, 2 * gst::ClockTime::SECOND);
set_time(
&pipeline,
2 * gst::ClockTime::SECOND + 10 * gst::ClockTime::MSECOND,
);
// Produce a fourth frame but only from the fallback source
// This should be output now
push_fallback_buffer(&pipeline, 3 * gst::ClockTime::SECOND);
set_time(
&pipeline,
3 * gst::ClockTime::SECOND + 10 * gst::ClockTime::MSECOND,
);
let buffer = pull_buffer(&pipeline);
assert_fallback_buffer!(buffer, Some(3 * gst::ClockTime::SECOND));
// Produce a fifth frame but only from the fallback source
// This should be output now
push_fallback_buffer(&pipeline, 4 * gst::ClockTime::SECOND);
set_time(
&pipeline,
4 * gst::ClockTime::SECOND + 10 * gst::ClockTime::MSECOND,
);
let buffer = pull_buffer(&pipeline);
assert_fallback_buffer!(buffer, Some(4 * gst::ClockTime::SECOND));
// Wait for EOS to arrive at appsink
push_eos(&pipeline);
push_fallback_eos(&pipeline);
wait_eos(&pipeline);
stop_pipeline(pipeline);
}
#[test]
fn test_immediate_fallback_live() {
test_immediate_fallback(true);
}
#[test]
fn test_immediate_fallback_not_live() {
test_immediate_fallback(false);
}
fn test_immediate_fallback(live: bool) {
let pipeline = setup_pipeline(Some(live), Some(true), None);
// Produce the first frame but only from the fallback source
push_fallback_buffer(&pipeline, gst::ClockTime::ZERO);
set_time(&pipeline, gst::ClockTime::ZERO);
let buffer = pull_buffer(&pipeline);
assert_fallback_buffer!(buffer, Some(gst::ClockTime::ZERO));
// Wait for EOS to arrive at appsink
push_eos(&pipeline);
push_fallback_eos(&pipeline);
wait_eos(&pipeline);
stop_pipeline(pipeline);
}
#[test]
fn test_manual_switch_live() {
test_manual_switch(true);
}
#[test]
fn test_manual_switch_not_live() {
test_manual_switch(false);
}
fn test_manual_switch(live: bool) {
let pipeline = setup_pipeline(Some(live), None, Some(false));
let switch = pipeline.by_name("switch").unwrap();
let mainsink = switch.static_pad("sink_0").unwrap();
let fallbacksink = switch.static_pad("sink_1").unwrap();
switch.set_property("active-pad", &mainsink);
push_buffer(&pipeline, gst::ClockTime::ZERO);
push_fallback_buffer(&pipeline, gst::ClockTime::ZERO);
set_time(&pipeline, gst::ClockTime::ZERO + LATENCY);
let buffer = pull_buffer(&pipeline);
assert_buffer!(buffer, Some(gst::ClockTime::ZERO));
switch.set_property("active-pad", &fallbacksink);
push_fallback_buffer(&pipeline, gst::ClockTime::SECOND);
push_buffer(&pipeline, gst::ClockTime::SECOND);
set_time(&pipeline, gst::ClockTime::SECOND + LATENCY);
let mut buffer = pull_buffer(&pipeline);
// FIXME: Sometimes we get the ZERO buffer from the fallback sink instead
if buffer.pts() == Some(gst::ClockTime::ZERO) {
buffer = pull_buffer(&pipeline);
}
assert_fallback_buffer!(buffer, Some(gst::ClockTime::SECOND));
switch.set_property("active-pad", &mainsink);
push_buffer(&pipeline, 2 * gst::ClockTime::SECOND);
push_fallback_buffer(&pipeline, 2 * gst::ClockTime::SECOND);
set_time(&pipeline, 2 * gst::ClockTime::SECOND + LATENCY);
let buffer = pull_buffer(&pipeline);
assert_buffer!(buffer, Some(2 * gst::ClockTime::SECOND));
drop(mainsink);
drop(fallbacksink);
drop(switch);
// EOS on the fallback should not be required
push_eos(&pipeline);
wait_eos(&pipeline);
stop_pipeline(pipeline);
}
struct Pipeline {
pipeline: gst::Pipeline,
clock_join_handle: Option<std::thread::JoinHandle<()>>,
}
impl std::ops::Deref for Pipeline {
type Target = gst::Pipeline;
fn deref(&self) -> &gst::Pipeline {
&self.pipeline
}
}
fn setup_pipeline(
with_live_fallback: Option<bool>,
immediate_fallback: Option<bool>,
auto_switch: Option<bool>,
) -> Pipeline {
init();
debug!(TEST_CAT, "Setting up pipeline");
let clock = gst_check::TestClock::new();
clock.set_time(gst::ClockTime::ZERO);
let pipeline = gst::Pipeline::new(None);
// Running time 0 in our pipeline is going to be clock time 1s. All
// clock ids before 1s are used for signalling to our clock advancing
// thread.
pipeline.use_clock(Some(&clock));
pipeline.set_base_time(gst::ClockTime::SECOND);
pipeline.set_start_time(gst::ClockTime::NONE);
let src = gst::ElementFactory::make("appsrc", Some("src"))
.unwrap()
.downcast::<gst_app::AppSrc>()
.unwrap();
src.set_property("is-live", true);
src.set_property("format", gst::Format::Time);
src.set_property("min-latency", LATENCY.nseconds() as i64);
src.set_property(
"caps",
gst::Caps::builder("video/x-raw")
.field("format", "ARGB")
.field("width", 320i32)
.field("height", 240i32)
.field("framerate", gst::Fraction::new(1, 1))
.build(),
);
let switch = gst::ElementFactory::make("fallbackswitch", Some("switch")).unwrap();
switch.set_property("timeout", 3 * gst::ClockTime::SECOND);
if let Some(imm) = immediate_fallback {
switch.set_property("immediate-fallback", imm);
}
if let Some(auto_switch) = auto_switch {
switch.set_property("auto-switch", auto_switch);
}
let sink = gst::ElementFactory::make("appsink", Some("sink"))
.unwrap()
.downcast::<gst_app::AppSink>()
.unwrap();
sink.set_property("sync", false);
let queue = gst::ElementFactory::make("queue", None).unwrap();
pipeline
.add_many(&[src.upcast_ref(), &switch, &queue, sink.upcast_ref()])
.unwrap();
src.link_pads(Some("src"), &switch, Some("sink_0")).unwrap();
switch.link_pads(Some("src"), &queue, Some("sink")).unwrap();
queue.link_pads(Some("src"), &sink, Some("sink")).unwrap();
if let Some(live) = with_live_fallback {
let fallback_src = gst::ElementFactory::make("appsrc", Some("fallback-src"))
.unwrap()
.downcast::<gst_app::AppSrc>()
.unwrap();
fallback_src.set_property("is-live", live);
fallback_src.set_property("format", gst::Format::Time);
fallback_src.set_property("min-latency", LATENCY.nseconds() as i64);
fallback_src.set_property(
"caps",
gst::Caps::builder("video/x-raw")
.field("format", "ARGB")
.field("width", 160i32)
.field("height", 120i32)
.field("framerate", gst::Fraction::new(1, 1))
.build(),
);
pipeline.add(&fallback_src).unwrap();
fallback_src
.link_pads(Some("src"), &switch, Some("sink_1"))
.unwrap();
}
pipeline.set_state(gst::State::Playing).unwrap();
let clock_join_handle = std::thread::spawn(move || {
loop {
while let Some(clock_id) = clock.peek_next_pending_id().and_then(|clock_id| {
// Process if the clock ID is in the past or now
if clock.time().map_or(false, |time| time >= clock_id.time()) {
Some(clock_id)
} else {
None
}
}) {
debug!(
TEST_CAT,
"Processing clock ID {} at {:?}",
clock_id.time(),
clock.time()
);
if let Some(clock_id) = clock.process_next_clock_id() {
debug!(TEST_CAT, "Processed clock ID {}", clock_id.time());
if clock_id.time().is_zero() {
debug!(TEST_CAT, "Stopping clock thread");
return;
}
}
}
// Sleep for 5ms as long as we have pending clock IDs that are in the future
// at the top of the queue. We don't want to do a busy loop here.
while clock.peek_next_pending_id().iter().any(|clock_id| {
// Sleep if the clock ID is in the future
// FIXME probably can expect clock.time()
clock
.time()
.map_or(true, |clock_time| clock_time < clock_id.time())
}) {
use std::{thread, time};
thread::sleep(time::Duration::from_millis(10));
}
// Otherwise if there are none (or they are ready now) wait until there are
// clock ids again
let _ = clock.wait_for_next_pending_id();
}
});
Pipeline {
pipeline,
clock_join_handle: Some(clock_join_handle),
}
}
fn push_buffer(pipeline: &Pipeline, time: gst::ClockTime) {
let src = pipeline
.by_name("src")
.unwrap()
.downcast::<gst_app::AppSrc>()
.unwrap();
let mut buffer = gst::Buffer::with_size(320 * 240 * 4).unwrap();
{
let buffer = buffer.get_mut().unwrap();
buffer.set_pts(time);
}
src.push_buffer(buffer).unwrap();
}
fn push_fallback_buffer(pipeline: &Pipeline, time: gst::ClockTime) {
let src = pipeline
.by_name("fallback-src")
.unwrap()
.downcast::<gst_app::AppSrc>()
.unwrap();
let mut buffer = gst::Buffer::with_size(160 * 120 * 4).unwrap();
{
let buffer = buffer.get_mut().unwrap();
buffer.set_pts(time);
}
src.push_buffer(buffer).unwrap();
}
fn push_eos(pipeline: &Pipeline) {
let src = pipeline
.by_name("src")
.unwrap()
.downcast::<gst_app::AppSrc>()
.unwrap();
src.end_of_stream().unwrap();
}
fn push_fallback_eos(pipeline: &Pipeline) {
let src = pipeline
.by_name("fallback-src")
.unwrap()
.downcast::<gst_app::AppSrc>()
.unwrap();
src.end_of_stream().unwrap();
}
fn pull_buffer(pipeline: &Pipeline) -> gst::Buffer {
let sink = pipeline
.by_name("sink")
.unwrap()
.downcast::<gst_app::AppSink>()
.unwrap();
let sample = sink.pull_sample().unwrap();
sample.buffer_owned().unwrap()
}
fn set_time(pipeline: &Pipeline, time: gst::ClockTime) {
let clock = pipeline
.clock()
.unwrap()
.downcast::<gst_check::TestClock>()
.unwrap();
debug!(TEST_CAT, "Setting time to {}", time);
clock.set_time(gst::ClockTime::SECOND + time);
}
fn wait_eos(pipeline: &Pipeline) {
let sink = pipeline
.by_name("sink")
.unwrap()
.downcast::<gst_app::AppSink>()
.unwrap();
// FIXME: Ideally without a sleep
loop {
use std::{thread, time};
if sink.is_eos() {
debug!(TEST_CAT, "Waited for EOS");
break;
}
thread::sleep(time::Duration::from_millis(10));
}
}
fn stop_pipeline(mut pipeline: Pipeline) {
pipeline.set_state(gst::State::Null).unwrap();
let clock = pipeline
.clock()
.unwrap()
.downcast::<gst_check::TestClock>()
.unwrap();
// Signal shutdown to the clock thread
let clock_id = clock.new_single_shot_id(gst::ClockTime::ZERO);
let _ = clock_id.wait();
let switch = pipeline.by_name("switch").unwrap();
let switch_weak = switch.downgrade();
drop(switch);
let pipeline_weak = pipeline.downgrade();
pipeline.clock_join_handle.take().unwrap().join().unwrap();
drop(pipeline);
assert!(switch_weak.upgrade().is_none());
assert!(pipeline_weak.upgrade().is_none());
}