add snapshotting tracer

Convenient tracer to dump all the existing pipelines when receiving the
SIGUSR1 Unix signal.
This commit is contained in:
Guillaume Desmottes 2022-05-18 17:22:34 +02:00
parent d18270a391
commit 351453c132
8 changed files with 347 additions and 1 deletions

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@ -18,6 +18,7 @@ members = [
"net/rusoto", "net/rusoto",
"utils/fallbackswitch", "utils/fallbackswitch",
"utils/togglerecord", "utils/togglerecord",
"utils/tracers",
"utils/uriplaylistbin", "utils/uriplaylistbin",
"video/cdg", "video/cdg",
"video/closedcaption", "video/closedcaption",
@ -52,6 +53,7 @@ default-members = [
"net/rusoto", "net/rusoto",
"utils/fallbackswitch", "utils/fallbackswitch",
"utils/togglerecord", "utils/togglerecord",
"utils/tracers",
"utils/uriplaylistbin", "utils/uriplaylistbin",
"video/cdg", "video/cdg",
"video/ffv1", "video/ffv1",

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@ -4,7 +4,8 @@ DIRS = ['audio', 'generic', 'net', 'text', 'utils', 'video']
# Plugins whose name is prefixed by 'rs' # Plugins whose name is prefixed by 'rs'
RS_PREFIXED = ['audiofx', 'closedcaption', RS_PREFIXED = ['audiofx', 'closedcaption',
'dav1d', 'file', 'json', 'onvif', 'regex', 'webp'] 'dav1d', 'file', 'json', 'onvif', 'regex', 'webp']
OVERRIDE = {'wrap': 'rstextwrap', 'flavors': 'rsflv', 'ahead': 'textahead'} OVERRIDE = {'wrap': 'rstextwrap', 'flavors': 'rsflv',
'ahead': 'textahead', 'tracers': 'rstracers'}
def iterate_plugins(): def iterate_plugins():

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@ -62,6 +62,7 @@ plugins = {
'gst-plugin-spotify': 'libgstspotify', 'gst-plugin-spotify': 'libgstspotify',
'gst-plugin-textahead': 'libgsttextahead', 'gst-plugin-textahead': 'libgsttextahead',
'gst-plugin-onvif': 'libgstrsonvif', 'gst-plugin-onvif': 'libgstrsonvif',
'gst-plugin-tracers': 'libgstrstracers',
} }
extra_env = {} extra_env = {}

41
utils/tracers/Cargo.toml Normal file
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@ -0,0 +1,41 @@
[package]
name = "gst-plugin-tracers"
version = "0.9.0"
authors = ["Guillaume Desmottes <guillaume.desmottes@onestream.live>"]
repository = "https://gitlab.freedesktop.org/gstreamer/gst-plugins-rs"
license = "MPL-2.0"
edition = "2018"
description = "GStreamer tracers plugin"
[dependencies]
gst = { package = "gstreamer", git = "https://gitlab.freedesktop.org/gstreamer/gstreamer-rs" }
once_cell = "1.0"
anyhow = "1"
[target.'cfg(unix)'.dependencies]
signal-hook = "0.3"
[lib]
name = "gstrstracers"
crate-type = ["cdylib", "rlib"]
path = "src/lib.rs"
[build-dependencies]
gst-plugin-version-helper = { path="../../version-helper" }
[features]
static = []
capi = []
[package.metadata.capi]
min_version = "0.8.0"
[package.metadata.capi.header]
enabled = false
[package.metadata.capi.library]
install_subdir = "gstreamer-1.0"
versioning = false
[package.metadata.capi.pkg_config]
requires_private = "gstreamer-1.0, gobject-2.0, glib-2.0, gmodule-2.0"

3
utils/tracers/build.rs Normal file
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@ -0,0 +1,3 @@
fn main() {
gst_plugin_version_helper::info()
}

30
utils/tracers/src/lib.rs Normal file
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@ -0,0 +1,30 @@
// Copyright (C) 2022 OneStream Live <guillaume.desmottes@onestream.live>
//
// 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
#![allow(clippy::non_send_fields_in_send_ty)]
use gst::glib;
mod pipeline_snapshot;
fn plugin_init(plugin: &gst::Plugin) -> Result<(), glib::BoolError> {
pipeline_snapshot::register(plugin)?;
Ok(())
}
gst::plugin_define!(
rstracers,
env!("CARGO_PKG_DESCRIPTION"),
plugin_init,
concat!(env!("CARGO_PKG_VERSION"), "-", env!("COMMIT_ID")),
// FIXME: MPL-2.0 is only allowed since 1.18.3 (as unknown) and 1.20 (as known)
"MPL",
env!("CARGO_PKG_NAME"),
env!("CARGO_PKG_NAME"),
env!("CARGO_PKG_REPOSITORY"),
env!("BUILD_REL_DATE")
);

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@ -0,0 +1,244 @@
// Copyright (C) 2022 OneStream Live <guillaume.desmottes@onestream.live>
//
// 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
/// This tracer provides an easy way to take a snapshot of all the pipelines without
/// having to modify the application.
/// One just have to load the tracer and send the `SIGUSR1` UNIX signal to take snapshots.
/// It currently only works on UNIX systems.
///
/// When taking a snapshot pipelines are saved to DOT files, but the tracer may be
/// extended in the future to dump more information.
///
/// Example:
///
/// ```console
/// $ GST_TRACERS="pipeline-snapshot" GST_DEBUG_DUMP_DOT_DIR=. gst-launch-1.0 audiotestsrc ! fakesink
/// ```
/// You can then trigger a snapshot using:
/// ```console
/// $ kill -SIGUSR1 $(pidof gst-launch-1.0)
/// ```
///
/// Parameters can be passed to configure the tracer:
/// - `dot-prefix` (string, default: "pipeline-snapshot-"): when dumping pipelines to a `dot` file each file is named `$prefix$pipeline_name.dot`.
/// - `dot-ts` (boolean, default: "true"): if the current timestamp should be added as a prefix to each pipeline `dot` file.
///
/// Example:
///
/// ```console
/// $ GST_TRACERS="pipeline-snapshot(dot-prefix="badger-",dot-ts=false)" GST_DEBUG_DUMP_DOT_DIR=. gst-launch-1.0 audiotestsrc ! fakesink
/// ```
use std::collections::HashMap;
use std::str::FromStr;
use std::sync::{Arc, Mutex};
use gst::glib;
use gst::glib::translate::ToGlibPtr;
use gst::prelude::*;
use gst::subclass::prelude::*;
use once_cell::sync::Lazy;
static CAT: Lazy<gst::DebugCategory> = Lazy::new(|| {
gst::DebugCategory::new(
"pipeline-snapshot",
gst::DebugColorFlags::empty(),
Some("pipeline snapshot tracer"),
)
});
#[derive(Debug, PartialEq, Eq, PartialOrd, Ord, Hash)]
struct ElementPtr(std::ptr::NonNull<gst::ffi::GstElement>);
unsafe impl Send for ElementPtr {}
unsafe impl Sync for ElementPtr {}
impl ElementPtr {
fn from_ref(element: &gst::Element) -> Self {
let p = element.to_glib_none().0;
Self(std::ptr::NonNull::new(p).unwrap())
}
fn from_object_ptr(p: std::ptr::NonNull<gst::ffi::GstObject>) -> Self {
let p = p.cast();
Self(p)
}
}
#[derive(Debug)]
struct Settings {
dot_prefix: String,
dot_ts: bool,
}
impl Default for Settings {
fn default() -> Self {
Self {
dot_prefix: "pipeline-snapshot-".to_string(),
dot_ts: true,
}
}
}
impl Settings {
fn update_from_params(&mut self, obj: &super::PipelineSnapshot, params: String) {
let s = match gst::Structure::from_str(&format!("pipeline-snapshot,{}", params)) {
Ok(s) => s,
Err(err) => {
gst::warning!(CAT, obj: obj, "failed to parse tracer parameters: {}", err);
return;
}
};
if let Ok(dot_prefix) = s.get("dot-prefix") {
gst::log!(CAT, obj: obj, "dot-prefix = {}", dot_prefix);
self.dot_prefix = dot_prefix;
}
if let Ok(dot_ts) = s.get("dot-ts") {
gst::log!(CAT, obj: obj, "dot-ts = {}", dot_ts);
self.dot_ts = dot_ts;
}
}
}
#[derive(Default)]
pub struct PipelineSnapshot {
pipelines: Arc<Mutex<HashMap<ElementPtr, glib::WeakRef<gst::Element>>>>,
handles: Mutex<Option<Handles>>,
}
struct Handles {
#[cfg(unix)]
signal: signal_hook::iterator::Handle,
thread: std::thread::JoinHandle<()>,
}
#[glib::object_subclass]
impl ObjectSubclass for PipelineSnapshot {
const NAME: &'static str = "GstPipelineSnapshot";
type Type = super::PipelineSnapshot;
type ParentType = gst::Tracer;
}
impl ObjectImpl for PipelineSnapshot {
fn constructed(&self, obj: &Self::Type) {
self.parent_constructed(obj);
let mut settings = Settings::default();
if let Some(params) = obj.property::<Option<String>>("params") {
settings.update_from_params(obj, params);
}
self.register_hook(TracerHook::ElementNew);
self.register_hook(TracerHook::ObjectDestroyed);
if let Err(err) = self.setup_signal(settings) {
gst::warning!(CAT, obj: obj, "failed to setup UNIX signals: {}", err);
}
}
fn dispose(&self, _obj: &Self::Type) {
let mut handles = self.handles.lock().unwrap();
if let Some(handles) = handles.take() {
#[cfg(unix)]
handles.signal.close();
handles.thread.join().unwrap();
}
}
}
impl GstObjectImpl for PipelineSnapshot {}
impl TracerImpl for PipelineSnapshot {
fn element_new(&self, _ts: u64, element: &gst::Element) {
if element.is::<gst::Pipeline>() {
let tracer = self.instance();
gst::debug!(CAT, obj: &tracer, "new pipeline: {}", element.name());
let weak = element.downgrade();
let mut pipelines = self.pipelines.lock().unwrap();
pipelines.insert(ElementPtr::from_ref(element), weak);
}
}
fn object_destroyed(&self, _ts: u64, object: std::ptr::NonNull<gst::ffi::GstObject>) {
let mut pipelines = self.pipelines.lock().unwrap();
let object = ElementPtr::from_object_ptr(object);
pipelines.remove(&object);
}
}
impl PipelineSnapshot {
#[cfg(unix)]
fn setup_signal(&self, settings: Settings) -> anyhow::Result<()> {
use signal_hook::consts::signal::*;
use signal_hook::iterator::Signals;
let mut signals = Signals::new(&[SIGUSR1])?;
let signal_handle = signals.handle();
let tracer_weak = self.instance().downgrade();
let pipelines = self.pipelines.clone();
let thread_handle = std::thread::spawn(move || {
for signal in &mut signals {
match signal {
SIGUSR1 => {
let tracer = match tracer_weak.upgrade() {
Some(tracer) => tracer,
None => break,
};
let pipelines = {
let weaks = pipelines.lock().unwrap();
weaks
.values()
.filter_map(|w| w.upgrade())
.collect::<Vec<_>>()
};
for pipeline in pipelines.into_iter() {
let pipeline = pipeline.downcast::<gst::Pipeline>().unwrap();
gst::debug!(CAT, obj: &tracer, "dump {}", pipeline.name());
let dump_name = format!("{}{}", settings.dot_prefix, pipeline.name());
if settings.dot_ts {
gst::debug_bin_to_dot_file_with_ts(
&pipeline,
gst::DebugGraphDetails::all(),
&dump_name,
);
} else {
gst::debug_bin_to_dot_file(
&pipeline,
gst::DebugGraphDetails::all(),
&dump_name,
);
}
}
}
_ => unreachable!(),
}
}
});
let mut handles = self.handles.lock().unwrap();
*handles = Some(Handles {
signal: signal_handle,
thread: thread_handle,
});
Ok(())
}
#[cfg(not(unix))]
fn setup_signal(&self) -> anyhow::Result<()> {
anyhow::bail!("only supported on UNIX system");
}
}

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@ -0,0 +1,24 @@
// Copyright (C) 2022 OneStream Live <guillaume.desmottes@onestream.live>
//
// 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::glib;
use gst::prelude::*;
mod imp;
glib::wrapper! {
pub struct PipelineSnapshot(ObjectSubclass<imp::PipelineSnapshot>) @extends gst::Tracer, gst::Object;
}
pub fn register(plugin: &gst::Plugin) -> Result<(), glib::BoolError> {
gst::Tracer::register(
Some(plugin),
"pipeline-snapshot",
PipelineSnapshot::static_type(),
)
}