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ts/runtime: shuffle some structs to dedicated modules

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This commit is contained in:
François Laignel 2021-11-29 19:45:24 +01:00 committed by Sebastian Dröge
parent c5ef83d5b0
commit db9c38aa93
7 changed files with 765 additions and 490 deletions
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2
generic/threadshare/Cargo.toml
View file

@ -14,8 +14,8 @@ gio = { git = "https://github.com/gtk-rs/gtk-rs-core" }
gst = { package = "gstreamer", git = "https://gitlab.freedesktop.org/gstreamer/gstreamer-rs" }
gst-net = { package = "gstreamer-net", git = "https://gitlab.freedesktop.org/gstreamer/gstreamer-rs" }
gst-rtp = { package = "gstreamer-rtp", git = "https://gitlab.freedesktop.org/gstreamer/gstreamer-rs" }
pin-project = "1"
once_cell = "1"
pin-project-lite = "0.2.7"
tokio = { git = "https://github.com/fengalin/tokio", tag = "tokio-0.2.13-throttling.1", features = ["io-util", "macros", "rt-core", "sync", "stream", "time", "tcp", "udp", "rt-util"] }
futures = { version = "0.3", features = ["thread-pool"] }
rand = "0.8"

571
generic/threadshare/src/runtime/executor/context.rs
View file

@ -16,26 +16,18 @@
// Free Software Foundation, Inc., 51 Franklin Street, Suite 500,
// Boston, MA 02110-1335, USA.
use futures::channel::oneshot;
use futures::future::BoxFuture;
use futures::prelude::*;
use gst::{gst_debug, gst_log, gst_trace, gst_warning};
use gst::{gst_debug, gst_trace};
use once_cell::sync::Lazy;
use std::cell::RefCell;
use std::collections::{HashMap, VecDeque};
use std::fmt;
use std::collections::HashMap;
use std::io;
use std::mem;
use std::pin::Pin;
use std::sync::mpsc as sync_mpsc;
use std::sync::{Arc, Mutex, Weak};
use std::task::Poll;
use std::thread;
use std::sync::{Arc, Mutex};
use std::time::Duration;
use super::{Handle, HandleWeak, JoinHandle, Scheduler, SubTaskOutput, TaskId};
use crate::runtime::RUNTIME_CAT;
// We are bound to using `sync` for the `runtime` `Mutex`es. Attempts to use `async` `Mutex`es
@ -48,15 +40,9 @@ use crate::runtime::RUNTIME_CAT;
//
// Also, we want to be able to `acquire` a `Context` outside of an `async` context.
// These `Mutex`es must be `lock`ed for a short period.
static CONTEXTS: Lazy<Mutex<HashMap<String, Weak<ContextInner>>>> =
static CONTEXTS: Lazy<Mutex<HashMap<Arc<str>, ContextWeak>>> =
Lazy::new(|| Mutex::new(HashMap::new()));
thread_local!(static CURRENT_THREAD_CONTEXT: RefCell<Option<ContextWeak>> = RefCell::new(None));
tokio::task_local! {
static CURRENT_TASK_ID: TaskId;
}
/// Blocks on `future` in one way or another if possible.
///
/// IO & time related `Future`s must be handled within their own [`Context`].
@ -98,43 +84,12 @@ pub fn block_on_or_add_sub_task<Fut: Future + Send + 'static>(future: Fut) -> Op
/// # Panics
///
/// This function panics if called within a [`Context`] thread.
pub fn block_on<Fut: Future>(future: Fut) -> Fut::Output {
pub fn block_on<F: Future>(future: F) -> F::Output {
assert!(!Context::is_context_thread());
// Not running in a Context thread so we can block
gst_debug!(RUNTIME_CAT, "Blocking on new dummy context");
let context = Context(Arc::new(ContextInner {
real: None,
task_queues: Mutex::new((0, HashMap::new())),
}));
CURRENT_THREAD_CONTEXT.with(move |cur_ctx| {
*cur_ctx.borrow_mut() = Some(context.downgrade());
let res = futures::executor::block_on(async move {
CURRENT_TASK_ID
.scope(TaskId(0), async move {
let task_id = CURRENT_TASK_ID.try_with(|task_id| *task_id).ok();
assert_eq!(task_id, Some(TaskId(0)));
let res = future.await;
while Context::current_has_sub_tasks() {
if Context::drain_sub_tasks().await.is_err() {
break;
}
}
res
})
.await
});
*cur_ctx.borrow_mut() = None;
res
})
Scheduler::block_on(future)
}
/// Yields execution back to the runtime
@ -143,222 +98,8 @@ pub async fn yield_now() {
tokio::task::yield_now().await;
}
struct ContextThread {
name: String,
}
impl ContextThread {
fn start(name: &str, wait: Duration) -> Context {
let context_thread = ContextThread { name: name.into() };
let (context_sender, context_receiver) = sync_mpsc::channel();
let join = thread::spawn(move || {
context_thread.spawn(wait, context_sender);
});
let context = context_receiver.recv().expect("Context thread init failed");
*context
.0
.real
.as_ref()
.unwrap()
.shutdown
.join
.lock()
.unwrap() = Some(join);
context
}
fn spawn(&self, wait: Duration, context_sender: sync_mpsc::Sender<Context>) {
gst_debug!(RUNTIME_CAT, "Started context thread '{}'", self.name);
let mut runtime = tokio::runtime::Builder::new()
.basic_scheduler()
.thread_name(self.name.clone())
.enable_all()
.max_throttling(wait)
.build()
.expect("Couldn't build the runtime");
let (shutdown_sender, shutdown_receiver) = oneshot::channel();
let shutdown = ContextShutdown {
name: self.name.clone(),
shutdown: Some(shutdown_sender),
join: Mutex::new(None),
};
let context = Context(Arc::new(ContextInner {
real: Some(ContextRealInner {
name: self.name.clone(),
wait_duration: wait,
handle: Mutex::new(runtime.handle().clone()),
shutdown,
}),
task_queues: Mutex::new((0, HashMap::new())),
}));
CURRENT_THREAD_CONTEXT.with(|cur_ctx| {
*cur_ctx.borrow_mut() = Some(context.downgrade());
});
context_sender.send(context).unwrap();
let _ = runtime.block_on(shutdown_receiver);
}
}
impl Drop for ContextThread {
fn drop(&mut self) {
gst_debug!(RUNTIME_CAT, "Terminated: context thread '{}'", self.name);
}
}
#[derive(Debug)]
struct ContextShutdown {
name: String,
shutdown: Option<oneshot::Sender<()>>,
join: Mutex<Option<thread::JoinHandle<()>>>,
}
impl Drop for ContextShutdown {
fn drop(&mut self) {
gst_debug!(
RUNTIME_CAT,
"Shutting down context thread thread '{}'",
self.name
);
self.shutdown.take().unwrap();
gst_trace!(
RUNTIME_CAT,
"Waiting for context thread '{}' to shutdown",
self.name
);
let join_handle = self.join.lock().unwrap().take().unwrap();
let _ = join_handle.join();
}
}
#[derive(Clone, Copy, Eq, PartialEq, Hash, Debug)]
pub struct TaskId(u64);
pub type SubTaskOutput = Result<(), gst::FlowError>;
pub struct SubTaskQueue(VecDeque<BoxFuture<'static, SubTaskOutput>>);
impl fmt::Debug for SubTaskQueue {
fn fmt(&self, fmt: &mut fmt::Formatter<'_>) -> fmt::Result {
fmt.debug_tuple("SubTaskQueue").finish()
}
}
pub struct JoinError(tokio::task::JoinError);
impl fmt::Display for JoinError {
fn fmt(&self, fmt: &mut fmt::Formatter<'_>) -> fmt::Result {
fmt::Display::fmt(&self.0, fmt)
}
}
impl fmt::Debug for JoinError {
fn fmt(&self, fmt: &mut fmt::Formatter<'_>) -> fmt::Result {
fmt::Debug::fmt(&self.0, fmt)
}
}
impl std::error::Error for JoinError {}
impl From<tokio::task::JoinError> for JoinError {
fn from(src: tokio::task::JoinError) -> Self {
JoinError(src)
}
}
/// Wrapper for the underlying runtime JoinHandle implementation.
pub struct JoinHandle<T> {
join_handle: tokio::task::JoinHandle<T>,
context: ContextWeak,
task_id: TaskId,
}
unsafe impl<T: Send> Send for JoinHandle<T> {}
unsafe impl<T: Send> Sync for JoinHandle<T> {}
impl<T> JoinHandle<T> {
pub fn is_current(&self) -> bool {
if let Some((context, task_id)) = Context::current_task() {
let self_context = self.context.upgrade();
self_context.map(|c| c == context).unwrap_or(false) && task_id == self.task_id
} else {
false
}
}
pub fn context(&self) -> Option<Context> {
self.context.upgrade()
}
pub fn task_id(&self) -> TaskId {
self.task_id
}
}
impl<T> Unpin for JoinHandle<T> {}
impl<T> Future for JoinHandle<T> {
type Output = Result<T, JoinError>;
fn poll(mut self: Pin<&mut Self>, cx: &mut std::task::Context<'_>) -> Poll<Self::Output> {
if self.as_ref().is_current() {
panic!("Trying to join task {:?} from itself", self.as_ref());
}
self.as_mut()
.join_handle
.poll_unpin(cx)
.map_err(JoinError::from)
}
}
impl<T> fmt::Debug for JoinHandle<T> {
fn fmt(&self, fmt: &mut fmt::Formatter<'_>) -> fmt::Result {
let context_name = self.context.upgrade().map(|c| String::from(c.name()));
fmt.debug_struct("JoinHandle")
.field("context", &context_name)
.field("task_id", &self.task_id)
.finish()
}
}
#[derive(Debug)]
struct ContextRealInner {
name: String,
handle: Mutex<tokio::runtime::Handle>,
wait_duration: Duration,
// Only used for dropping
shutdown: ContextShutdown,
}
#[derive(Debug)]
struct ContextInner {
// Otherwise a dummy context
real: Option<ContextRealInner>,
task_queues: Mutex<(u64, HashMap<u64, SubTaskQueue>)>,
}
impl Drop for ContextInner {
fn drop(&mut self) {
if let Some(ref real) = self.real {
let mut contexts = CONTEXTS.lock().unwrap();
gst_debug!(RUNTIME_CAT, "Finalizing context '{}'", real.name);
contexts.remove(&real.name);
}
}
}
#[derive(Clone, Debug)]
pub struct ContextWeak(Weak<ContextInner>);
pub struct ContextWeak(HandleWeak);
impl ContextWeak {
pub fn upgrade(&self) -> Option<Context> {
@ -374,16 +115,14 @@ impl ContextWeak {
/// `Element` implementations should use [`PadSrc`] and [`PadSink`] which
/// provide high-level features.
///
/// See the [module-level documentation](index.html) for more.
///
/// [`PadSrc`]: ../pad/struct.PadSrc.html
/// [`PadSink`]: ../pad/struct.PadSink.html
#[derive(Clone, Debug)]
pub struct Context(Arc<ContextInner>);
pub struct Context(Handle);
impl PartialEq for Context {
fn eq(&self, other: &Self) -> bool {
Arc::ptr_eq(&self.0, &other.0)
self.0.eq(&other.0)
}
}
@ -391,90 +130,59 @@ impl Eq for Context {}
impl Context {
pub fn acquire(context_name: &str, wait: Duration) -> Result<Self, io::Error> {
assert_ne!(context_name, "DUMMY");
assert_ne!(context_name, Scheduler::DUMMY_NAME);
let mut contexts = CONTEXTS.lock().unwrap();
if let Some(inner_weak) = contexts.get(context_name) {
if let Some(inner_strong) = inner_weak.upgrade() {
gst_debug!(
RUNTIME_CAT,
"Joining Context '{}'",
inner_strong.real.as_ref().unwrap().name
);
return Ok(Context(inner_strong));
if let Some(context_weak) = contexts.get(context_name) {
if let Some(context) = context_weak.upgrade() {
gst_debug!(RUNTIME_CAT, "Joining Context '{}'", context.name());
return Ok(context);
}
}
let context = ContextThread::start(context_name, wait);
contexts.insert(context_name.into(), Arc::downgrade(&context.0));
let context = Context(Scheduler::start(context_name, wait));
contexts.insert(context_name.into(), context.downgrade());
gst_debug!(
RUNTIME_CAT,
"New Context '{}'",
context.0.real.as_ref().unwrap().name
);
gst_debug!(RUNTIME_CAT, "New Context '{}'", context.name());
Ok(context)
}
pub fn downgrade(&self) -> ContextWeak {
ContextWeak(Arc::downgrade(&self.0))
ContextWeak(self.0.downgrade())
}
pub fn name(&self) -> &str {
match self.0.real {
Some(ref real) => real.name.as_str(),
None => "DUMMY",
}
self.0.context_name()
}
// FIXME this could be renamed as max_throttling
// but then, all elements should also change their
// wait variables and properties to max_throttling.
pub fn wait_duration(&self) -> Duration {
match self.0.real {
Some(ref real) => real.wait_duration,
None => Duration::ZERO,
}
self.0.max_throttling()
}
/// Returns `true` if a `Context` is running on current thread.
pub fn is_context_thread() -> bool {
CURRENT_THREAD_CONTEXT.with(|cur_ctx| cur_ctx.borrow().is_some())
Scheduler::is_scheduler_thread()
}
/// Returns the `Context` running on current thread, if any.
pub fn current() -> Option<Context> {
CURRENT_THREAD_CONTEXT.with(|cur_ctx| {
cur_ctx
.borrow()
.as_ref()
.and_then(|ctx_weak| ctx_weak.upgrade())
})
Scheduler::current().map(Context)
}
/// Returns the `TaskId` running on current thread, if any.
pub fn current_task() -> Option<(Context, TaskId)> {
CURRENT_THREAD_CONTEXT.with(|cur_ctx| {
cur_ctx
.borrow()
.as_ref()
.and_then(|ctx_weak| ctx_weak.upgrade())
.and_then(|ctx| {
let task_id = CURRENT_TASK_ID.try_with(|task_id| *task_id).ok();
task_id.map(move |task_id| (ctx, task_id))
})
})
Scheduler::current().map(Context).zip(TaskId::current())
}
pub fn enter<F, R>(&self, f: F) -> R
where
F: FnOnce() -> R,
{
let real = match self.0.real {
Some(ref real) => real,
None => panic!("Can't enter on dummy context"),
};
real.handle.lock().unwrap().enter(f)
self.0.enter(f)
}
pub fn spawn<Fut>(&self, future: Fut) -> JoinHandle<Fut::Output>
@ -482,7 +190,7 @@ impl Context {
Fut: Future + Send + 'static,
Fut::Output: Send + 'static,
{
self.spawn_internal(future, false)
self.0.spawn(future, false)
}
pub fn awake_and_spawn<Fut>(&self, future: Fut) -> JoinHandle<Fut::Output>
@ -490,80 +198,7 @@ impl Context {
Fut: Future + Send + 'static,
Fut::Output: Send + 'static,
{
self.spawn_internal(future, true)
}
#[inline]
fn spawn_internal<Fut>(&self, future: Fut, must_awake: bool) -> JoinHandle<Fut::Output>
where
Fut: Future + Send + 'static,
Fut::Output: Send + 'static,
{
let real = match self.0.real {
Some(ref real) => real,
None => panic!("Can't spawn new tasks on dummy context"),
};
let mut task_queues = self.0.task_queues.lock().unwrap();
let id = task_queues.0;
task_queues.0 += 1;
task_queues.1.insert(id, SubTaskQueue(VecDeque::new()));
let id = TaskId(id);
gst_trace!(
RUNTIME_CAT,
"Spawning new task {:?} on context {}",
id,
real.name
);
let spawn_fut = async move {
let ctx = Context::current().unwrap();
let real = ctx.0.real.as_ref().unwrap();
gst_trace!(
RUNTIME_CAT,
"Running task {:?} on context {}",
id,
real.name
);
let res = CURRENT_TASK_ID.scope(id, future).await;
// Remove task from the list
{
let mut task_queues = ctx.0.task_queues.lock().unwrap();
if let Some(task_queue) = task_queues.1.remove(&id.0) {
let l = task_queue.0.len();
if l > 0 {
gst_warning!(
RUNTIME_CAT,
"Task {:?} on context {} has {} pending sub tasks",
id,
real.name,
l
);
}
}
}
gst_trace!(RUNTIME_CAT, "Task {:?} on context {} done", id, real.name);
res
};
let join_handle = {
if must_awake {
real.handle.lock().unwrap().awake_and_spawn(spawn_fut)
} else {
real.handle.lock().unwrap().spawn(spawn_fut)
}
};
JoinHandle {
join_handle,
context: self.downgrade(),
task_id: id,
}
self.0.spawn(future, true)
}
pub fn current_has_sub_tasks() -> bool {
@ -575,12 +210,7 @@ impl Context {
}
};
let task_queues = ctx.0.task_queues.lock().unwrap();
task_queues
.1
.get(&task_id.0)
.map(|t| !t.0.is_empty())
.unwrap_or(false)
ctx.0.has_sub_tasks(task_id)
}
pub fn add_sub_task<T>(sub_task: T) -> Result<(), T>
@ -595,31 +225,7 @@ impl Context {
}
};
let mut task_queues = ctx.0.task_queues.lock().unwrap();
match task_queues.1.get_mut(&task_id.0) {
Some(task_queue) => {
if let Some(ref real) = ctx.0.real {
gst_trace!(
RUNTIME_CAT,
"Adding subtask to {:?} on context {}",
task_id,
real.name
);
} else {
gst_trace!(
RUNTIME_CAT,
"Adding subtask to {:?} on dummy context",
task_id,
);
}
task_queue.0.push_back(sub_task.boxed());
Ok(())
}
None => {
gst_trace!(RUNTIME_CAT, "Task was removed in the meantime");
Err(sub_task)
}
}
ctx.0.add_sub_task(task_id, sub_task)
}
pub async fn drain_sub_tasks() -> SubTaskOutput {
@ -628,45 +234,13 @@ impl Context {
None => return Ok(()),
};
ctx.drain_sub_tasks_internal(task_id).await
ctx.0.drain_sub_tasks(task_id).await
}
}
fn drain_sub_tasks_internal(
&self,
id: TaskId,
) -> impl Future<Output = SubTaskOutput> + Send + 'static {
let mut task_queue = {
let mut task_queues = self.0.task_queues.lock().unwrap();
if let Some(task_queue) = task_queues.1.get_mut(&id.0) {
mem::replace(task_queue, SubTaskQueue(VecDeque::new()))
} else {
SubTaskQueue(VecDeque::new())
}
};
let name = self
.0
.real
.as_ref()
.map(|r| r.name.clone())
.unwrap_or_else(|| String::from("DUMMY"));
async move {
if !task_queue.0.is_empty() {
gst_log!(
RUNTIME_CAT,
"Scheduling draining {} sub tasks from {:?} on '{}'",
task_queue.0.len(),
id,
&name,
);
for task in task_queue.0.drain(..) {
task.await?;
}
}
Ok(())
}
impl From<Handle> for Context {
fn from(handle: Handle) -> Self {
Context(handle)
}
}
@ -680,6 +254,7 @@ mod tests {
use std::sync::Arc;
use std::time::{Duration, Instant};
use super::super::Scheduler;
use super::Context;
type Item = i32;
@ -692,19 +267,36 @@ mod tests {
fn block_on_task_id() {
gst::init().unwrap();
assert!(!Context::is_context_thread());
crate::runtime::executor::block_on(async {
let (_ctx, task_id) = Context::current_task().unwrap();
let (ctx, task_id) = Context::current_task().unwrap();
assert_eq!(ctx.name(), Scheduler::DUMMY_NAME);
assert_eq!(task_id, super::TaskId(0));
/* Adding the sub task fails
let res = Context::add_sub_task(async move {
let (_ctx, task_id) = Context::current_task().unwrap();
assert_eq!(task_id, super::TaskId(0));
Ok(())
});
assert!(res.is_ok());
*/
assert!(Context::is_context_thread());
});
assert!(!Context::is_context_thread());
}
#[test]
fn block_on_timer() {
gst::init().unwrap();
let elapsed = crate::runtime::executor::block_on(async {
let now = Instant::now();
crate::runtime::time::delay_for(DELAY).await;
now.elapsed()
});
assert!(elapsed >= DELAY);
}
#[test]
@ -713,7 +305,8 @@ mod tests {
let context = Context::acquire("context_task_id", SLEEP_DURATION).unwrap();
let join_handle = context.spawn(async {
let (_ctx, task_id) = Context::current_task().unwrap();
let (ctx, task_id) = Context::current_task().unwrap();
assert_eq!(ctx.name(), "context_task_id");
assert_eq!(task_id, super::TaskId(0));
});
futures::executor::block_on(join_handle).unwrap();
@ -810,7 +403,10 @@ mod tests {
let mut receiver = futures::executor::block_on(join_handle).unwrap();
// The last sub task should be simply dropped at this point
assert_eq!(receiver.try_next().unwrap(), None);
match receiver.try_next() {
Ok(None) | Err(_) => (),
other => panic!("Unexpected {:?}", other),
}
}
#[test]
@ -853,30 +449,33 @@ mod tests {
futures::executor::block_on(join_handle).unwrap_err();
}
#[tokio::test]
async fn enter_context_from_tokio() {
#[test]
fn enter_context_from_scheduler() {
gst::init().unwrap();
let context = Context::acquire("enter_context_from_tokio", SLEEP_DURATION).unwrap();
let mut socket = context
.enter(|| {
let saddr = SocketAddr::new(IpAddr::V4(Ipv4Addr::LOCALHOST), 5002);
let socket = UdpSocket::bind(saddr).unwrap();
tokio::net::UdpSocket::from_std(socket)
})
.unwrap();
let elapsed = crate::runtime::executor::block_on(async {
let context = Context::acquire("enter_context_from_tokio", SLEEP_DURATION).unwrap();
let mut socket = context
.enter(|| {
let saddr = SocketAddr::new(IpAddr::V4(Ipv4Addr::LOCALHOST), 5002);
let socket = UdpSocket::bind(saddr).unwrap();
tokio::net::UdpSocket::from_std(socket)
})
.unwrap();
let saddr = SocketAddr::new(IpAddr::V4(Ipv4Addr::LOCALHOST), 4000);
let bytes_sent = socket.send_to(&[0; 10], saddr).await.unwrap();
assert_eq!(bytes_sent, 10);
let saddr = SocketAddr::new(IpAddr::V4(Ipv4Addr::LOCALHOST), 4000);
let bytes_sent = socket.send_to(&[0; 10], saddr).await.unwrap();
assert_eq!(bytes_sent, 10);
let elapsed = context.enter(|| {
futures::executor::block_on(async {
let now = Instant::now();
crate::runtime::time::delay_for(DELAY).await;
now.elapsed()
context.enter(|| {
futures::executor::block_on(async {
let now = Instant::now();
crate::runtime::time::delay_for(DELAY).await;
now.elapsed()
})
})
});
// Due to throttling, `Delay` may be fired earlier
assert!(elapsed + SLEEP_DURATION / 2 >= DELAY);
}

106
generic/threadshare/src/runtime/executor/join.rs Normal file
View file

@ -0,0 +1,106 @@
// Copyright (C) 2018-2020 Sebastian Dröge <sebastian@centricular.com>
// Copyright (C) 2019-2021 François Laignel <fengalin@free.fr>
//
// This library is free software; you can redistribute it and/or
// modify it under the terms of the GNU Library General Public
// License as published by the Free Software Foundation; either
// version 2 of the License, or (at your option) any later version.
//
// This library is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
// Library General Public License for more details.
//
// You should have received a copy of the GNU Library General Public
// License along with this library; if not, write to the
// Free Software Foundation, Inc., 51 Franklin Street, Suite 500,
// Boston, MA 02110-1335, USA.
use futures::channel::oneshot;
use futures::prelude::*;
use std::fmt;
use std::future::Future;
use std::pin::Pin;
use std::task::Poll;
use super::context::Context;
use super::TaskId;
use super::{Handle, HandleWeak, Scheduler};
#[derive(Debug)]
pub struct JoinError(TaskId);
impl fmt::Display for JoinError {
fn fmt(&self, fmt: &mut fmt::Formatter<'_>) -> fmt::Result {
write!(fmt, "{:?} was Canceled", self.0)
}
}
impl std::error::Error for JoinError {}
pub struct JoinHandle<T> {
receiver: oneshot::Receiver<T>,
handle: HandleWeak,
task_id: TaskId,
}
unsafe impl<T: Send> Send for JoinHandle<T> {}
unsafe impl<T: Send> Sync for JoinHandle<T> {}
impl<T> JoinHandle<T> {
pub(super) fn new(receiver: oneshot::Receiver<T>, handle: &Handle, task_id: TaskId) -> Self {
JoinHandle {
receiver,
handle: handle.downgrade(),
task_id,
}
}
pub fn is_current(&self) -> bool {
if let Some((cur_scheduler, task_id)) = Scheduler::current().zip(TaskId::current()) {
self.handle.upgrade().map_or(false, |self_scheduler| {
self_scheduler == cur_scheduler && task_id == self.task_id
})
} else {
false
}
}
pub fn context(&self) -> Option<Context> {
self.handle.upgrade().map(Context::from)
}
pub fn task_id(&self) -> TaskId {
self.task_id
}
}
impl<T> Future for JoinHandle<T> {
type Output = Result<T, JoinError>;
fn poll(mut self: Pin<&mut Self>, cx: &mut std::task::Context<'_>) -> Poll<Self::Output> {
if self.as_ref().is_current() {
panic!("Trying to join task {:?} from itself", self.as_ref());
}
self.as_mut()
.receiver
.poll_unpin(cx)
.map_err(|_| JoinError(self.task_id))
}
}
impl<T> fmt::Debug for JoinHandle<T> {
fn fmt(&self, fmt: &mut fmt::Formatter<'_>) -> fmt::Result {
let context_name = self
.handle
.upgrade()
.map(|handle| handle.context_name().to_owned());
fmt.debug_struct("JoinHandle")
.field("context", &context_name)
.field("task_id", &self.task_id)
.finish()
}
}

27
generic/threadshare/src/runtime/executor/mod.rs
View file

@ -34,6 +34,27 @@
//! [`PadSink`]: ../pad/struct.PadSink.html
mod context;
pub use context::{
block_on, block_on_or_add_sub_task, yield_now, Context, JoinHandle, SubTaskOutput, TaskId,
};
pub use context::{block_on, block_on_or_add_sub_task, yield_now, Context};
mod scheduler;
use scheduler::{Handle, HandleWeak, Scheduler};
mod join;
pub use join::JoinHandle;
mod task;
pub use task::{SubTaskOutput, TaskId};
struct CallOnDrop<F: FnOnce()>(Option<F>);
impl<F: FnOnce()> CallOnDrop<F> {
fn new(f: F) -> Self {
CallOnDrop(Some(f))
}
}
impl<F: FnOnce()> Drop for CallOnDrop<F> {
fn drop(&mut self) {
self.0.take().unwrap()()
}
}

319
generic/threadshare/src/runtime/executor/scheduler.rs Normal file
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@ -0,0 +1,319 @@
// Copyright (C) 2018-2020 Sebastian Dröge <sebastian@centricular.com>
// Copyright (C) 2019-2021 François Laignel <fengalin@free.fr>
//
// This library is free software; you can redistribute it and/or
// modify it under the terms of the GNU Library General Public
// License as published by the Free Software Foundation; either
// version 2 of the License, or (at your option) any later version.
//
// This library is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
// Library General Public License for more details.
//
// You should have received a copy of the GNU Library General Public
// License along with this library; if not, write to the
// Free Software Foundation, Inc., 51 Franklin Street, Suite 500,
// Boston, MA 02110-1335, USA.
use futures::channel::oneshot;
use gio::glib::clone::Downgrade;
use gst::{gst_debug, gst_trace};
use std::cell::RefCell;
use std::future::Future;
use std::sync::mpsc as sync_mpsc;
use std::sync::{Arc, Mutex, Weak};
use std::thread;
use std::time::Duration;
use super::task::{SubTaskOutput, TaskFuture, TaskId, TaskQueue};
use super::{CallOnDrop, JoinHandle};
use crate::runtime::RUNTIME_CAT;
thread_local! {
static CURRENT_SCHEDULER: RefCell<Option<Weak<Scheduler>>> = RefCell::new(None);
}
#[derive(Debug)]
pub(super) struct Scheduler {
context_name: Arc<str>,
max_throttling: Duration,
task_queue: Mutex<TaskQueue>,
rt_handle: Mutex<tokio::runtime::Handle>,
shutdown: Mutex<Option<SchedulerShutdown>>,
}
impl Scheduler {
pub const DUMMY_NAME: &'static str = "DUMMY";
pub fn start(context_name: &str, max_throttling: Duration) -> Handle {
let context_name = Arc::from(context_name);
let (handle_sender, handle_receiver) = sync_mpsc::channel();
let (shutdown_sender, shutdown_receiver) = oneshot::channel();
let thread_ctx_name = Arc::clone(&context_name);
let join = thread::spawn(move || {
gst_debug!(
RUNTIME_CAT,
"Started Scheduler thread for Context '{}'",
thread_ctx_name
);
let (mut rt, handle) = Scheduler::init(thread_ctx_name, max_throttling);
handle_sender.send(handle.clone()).unwrap();
let _ = rt.block_on(shutdown_receiver);
});
let handle = handle_receiver.recv().expect("Context thread init failed");
*handle.0.shutdown.lock().unwrap() = Some(SchedulerShutdown {
context_name,
sender: Some(shutdown_sender),
join: Some(join),
});
handle
}
fn init(context_name: Arc<str>, max_throttling: Duration) -> (tokio::runtime::Runtime, Handle) {
let runtime = tokio::runtime::Builder::new()
.basic_scheduler()
.enable_all()
.max_throttling(max_throttling)
.build()
.expect("Couldn't build the runtime");
let scheduler = Arc::new(Scheduler {
context_name: context_name.clone(),
max_throttling,
task_queue: Mutex::new(TaskQueue::new(context_name)),
rt_handle: Mutex::new(runtime.handle().clone()),
shutdown: Mutex::new(None),
});
CURRENT_SCHEDULER.with(|cur_scheduler| {
*cur_scheduler.borrow_mut() = Some(scheduler.downgrade());
});
(runtime, scheduler.into())
}
pub fn block_on<F: Future>(future: F) -> <F as Future>::Output {
assert!(
!Scheduler::is_scheduler_thread(),
"Attempt at blocking on from an existing Scheduler thread."
);
let (mut rt, handle) = Scheduler::init(Scheduler::DUMMY_NAME.into(), Duration::ZERO);
let handle_clone = handle.clone();
let task = handle.0.task_queue.lock().unwrap().add(async move {
let res = future.await;
let task_id = TaskId::current().unwrap();
while handle_clone.has_sub_tasks(task_id) {
if handle_clone.drain_sub_tasks(task_id).await.is_err() {
break;
}
}
res
});
let task_id = task.id();
gst_trace!(RUNTIME_CAT, "Blocking on current thread with {:?}", task_id,);
let _guard = CallOnDrop::new(|| {
gst_trace!(
RUNTIME_CAT,
"Blocking on current thread with {:?} done",
task_id,
);
handle.remove_task(task_id);
});
rt.block_on(task)
}
pub(super) fn is_scheduler_thread() -> bool {
CURRENT_SCHEDULER.with(|cur_scheduler| cur_scheduler.borrow().is_some())
}
pub(super) fn current() -> Option<Handle> {
CURRENT_SCHEDULER.with(|cur_scheduler| {
cur_scheduler
.borrow()
.as_ref()
.and_then(Weak::upgrade)
.map(Handle::from)
})
}
}
impl Drop for Scheduler {
fn drop(&mut self) {
// No more strong handlers point to this
// Scheduler, so remove its thread local key.
let _ = CURRENT_SCHEDULER.try_with(|cur_scheduler| {
*cur_scheduler.borrow_mut() = None;
});
gst_debug!(
RUNTIME_CAT,
"Terminated: Scheduler for Context '{}'",
self.context_name
);
}
}
#[derive(Debug)]
pub(super) struct SchedulerShutdown {
context_name: Arc<str>,
sender: Option<oneshot::Sender<()>>,
join: Option<thread::JoinHandle<()>>,
}
impl Drop for SchedulerShutdown {
fn drop(&mut self) {
gst_debug!(
RUNTIME_CAT,
"Shutting down Scheduler thread for Context '{}'",
self.context_name
);
self.sender.take().unwrap();
gst_trace!(
RUNTIME_CAT,
"Waiting for Scheduler to shutdown for Context '{}'",
self.context_name
);
let _ = self.join.take().unwrap().join();
}
}
#[derive(Clone, Debug)]
pub(super) struct HandleWeak(Weak<Scheduler>);
impl HandleWeak {
pub(super) fn upgrade(&self) -> Option<Handle> {
self.0.upgrade().map(Handle)
}
}
#[derive(Clone, Debug)]
pub(super) struct Handle(Arc<Scheduler>);
impl Handle {
pub fn context_name(&self) -> &str {
&self.0.context_name
}
pub fn max_throttling(&self) -> Duration {
self.0.max_throttling
}
pub fn enter<F, R>(&self, f: F) -> R
where
F: FnOnce() -> R,
{
self.0.rt_handle.lock().unwrap().enter(f)
}
pub fn add_task<F: Future>(&self, future: F) -> TaskFuture<F> {
let task = self.0.task_queue.lock().unwrap().add(future);
task
}
pub fn remove_task(&self, task_id: TaskId) {
self.0.task_queue.lock().unwrap().remove(task_id);
}
pub fn spawn<F>(&self, future: F, must_awake: bool) -> JoinHandle<F::Output>
where
F: Future + Send + 'static,
F::Output: Send + 'static,
{
let task = self.add_task(future);
let task_id = task.id();
let (sender, receiver) = oneshot::channel();
gst_trace!(
RUNTIME_CAT,
"Spawning new task_id {:?} on context {}",
task.id(),
self.0.context_name
);
let this = self.clone();
let spawn_fut = async move {
gst_trace!(
RUNTIME_CAT,
"Running task_id {:?} on context {}",
task_id,
this.context_name()
);
let _guard = CallOnDrop::new(|| {
gst_trace!(
RUNTIME_CAT,
"Task {:?} on context {} done",
task_id,
this.context_name()
);
this.0.task_queue.lock().unwrap().remove(task_id);
});
let _ = sender.send(task.await);
};
if must_awake {
let _ = self.0.rt_handle.lock().unwrap().awake_and_spawn(spawn_fut);
} else {
let _ = self.0.rt_handle.lock().unwrap().spawn(spawn_fut);
}
JoinHandle::new(receiver, self, task_id)
}
pub fn has_sub_tasks(&self, task_id: TaskId) -> bool {
let ret = self.0.task_queue.lock().unwrap().has_sub_tasks(task_id);
ret
}
pub fn add_sub_task<T>(&self, task_id: TaskId, sub_task: T) -> Result<(), T>
where
T: Future<Output = SubTaskOutput> + Send + 'static,
{
let res = self
.0
.task_queue
.lock()
.unwrap()
.add_sub_task(task_id, sub_task);
res
}
pub fn downgrade(&self) -> HandleWeak {
HandleWeak(self.0.downgrade())
}
pub async fn drain_sub_tasks(&self, task_id: TaskId) -> SubTaskOutput {
let sub_tasks_fut = self.0.task_queue.lock().unwrap().drain_sub_tasks(task_id);
sub_tasks_fut.await
}
}
impl From<Arc<Scheduler>> for Handle {
fn from(arc: Arc<Scheduler>) -> Self {
Handle(arc)
}
}
impl PartialEq for Handle {
fn eq(&self, other: &Self) -> bool {
Arc::ptr_eq(&self.0, &other.0)
}
}

229
generic/threadshare/src/runtime/executor/task.rs Normal file
View file

@ -0,0 +1,229 @@
// Copyright (C) 2018-2020 Sebastian Dröge <sebastian@centricular.com>
// Copyright (C) 2019-2021 François Laignel <fengalin@free.fr>
//
// This library is free software; you can redistribute it and/or
// modify it under the terms of the GNU Library General Public
// License as published by the Free Software Foundation; either
// version 2 of the License, or (at your option) any later version.
//
// This library is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
// Library General Public License for more details.
//
// You should have received a copy of the GNU Library General Public
// License along with this library; if not, write to the
// Free Software Foundation, Inc., 51 Franklin Street, Suite 500,
// Boston, MA 02110-1335, USA.
use futures::future::BoxFuture;
use futures::prelude::*;
use gst::{gst_log, gst_trace, gst_warning};
use pin_project_lite::pin_project;
use std::cell::Cell;
use std::collections::{HashMap, VecDeque};
use std::fmt;
use std::pin::Pin;
use std::sync::Arc;
use std::task::Poll;
use crate::runtime::RUNTIME_CAT;
thread_local! {
static CURRENT_TASK_ID: Cell<Option<TaskId>> = Cell::new(None);
}
#[derive(Clone, Copy, Eq, PartialEq, Hash, Debug)]
pub struct TaskId(pub(super) u64);
impl TaskId {
const LAST: TaskId = TaskId(u64::MAX);
fn next(task_id: Self) -> Self {
TaskId(task_id.0.wrapping_add(1))
}
pub(super) fn current() -> Option<TaskId> {
CURRENT_TASK_ID.try_with(Cell::get).ok().flatten()
}
}
pub type SubTaskOutput = Result<(), gst::FlowError>;
pin_project! {
pub(super) struct TaskFuture<F: Future> {
id: TaskId,
#[pin]
future: F,
}
}
impl<F: Future> TaskFuture<F> {
pub fn id(&self) -> TaskId {
self.id
}
}
impl<F: Future> Future for TaskFuture<F> {
type Output = F::Output;
fn poll(self: Pin<&mut Self>, cx: &mut std::task::Context<'_>) -> Poll<Self::Output> {
struct TaskIdGuard {
prev_task_id: Option<TaskId>,
}
impl Drop for TaskIdGuard {
fn drop(&mut self) {
let _ = CURRENT_TASK_ID.try_with(|cur| cur.replace(self.prev_task_id.take()));
}
}
let task_id = self.id;
let project = self.project();
let _guard = TaskIdGuard {
prev_task_id: CURRENT_TASK_ID.with(|cur| cur.replace(Some(task_id))),
};
project.future.poll(cx)
}
}
struct Task {
id: TaskId,
sub_tasks: VecDeque<BoxFuture<'static, SubTaskOutput>>,
}
impl Task {
fn new(id: TaskId) -> Self {
Task {
id,
sub_tasks: VecDeque::new(),
}
}
fn add_sub_task<T>(&mut self, sub_task: T)
where
T: Future<Output = SubTaskOutput> + Send + 'static,
{
self.sub_tasks.push_back(sub_task.boxed());
}
fn drain_sub_tasks(&mut self) -> VecDeque<BoxFuture<'static, SubTaskOutput>> {
std::mem::take(&mut self.sub_tasks)
}
}
impl fmt::Debug for Task {
fn fmt(&self, fmt: &mut fmt::Formatter<'_>) -> fmt::Result {
fmt.debug_struct("Task")
.field("id", &self.id)
.field("sub_tasks len", &self.sub_tasks.len())
.finish()
}
}
#[derive(Debug)]
pub(super) struct TaskQueue {
last_task_id: TaskId,
tasks: HashMap<TaskId, Task>,
context_name: Arc<str>,
}
impl TaskQueue {
pub fn new(context_name: Arc<str>) -> Self {
TaskQueue {
last_task_id: TaskId::LAST,
tasks: HashMap::default(),
context_name,
}
}
pub fn add<F: Future>(&mut self, future: F) -> TaskFuture<F> {
self.last_task_id = TaskId::next(self.last_task_id);
self.tasks
.insert(self.last_task_id, Task::new(self.last_task_id));
TaskFuture {
id: self.last_task_id,
future,
}
}
pub fn remove(&mut self, task_id: TaskId) {
if let Some(task) = self.tasks.remove(&task_id) {
if !task.sub_tasks.is_empty() {
gst_warning!(
RUNTIME_CAT,
"Task {:?} on context {} has {} pending sub tasks",
task_id,
self.context_name,
task.sub_tasks.len(),
);
}
}
}
pub fn has_sub_tasks(&self, task_id: TaskId) -> bool {
self.tasks
.get(&task_id)
.map(|t| !t.sub_tasks.is_empty())
.unwrap_or(false)
}
pub fn add_sub_task<T>(&mut self, task_id: TaskId, sub_task: T) -> Result<(), T>
where
T: Future<Output = SubTaskOutput> + Send + 'static,
{
match self.tasks.get_mut(&task_id) {
Some(task) => {
gst_trace!(
RUNTIME_CAT,
"Adding subtask to {:?} on context {}",
task_id,
self.context_name
);
task.add_sub_task(sub_task);
Ok(())
}
None => {
gst_trace!(RUNTIME_CAT, "Task was removed in the meantime");
Err(sub_task)
}
}
}
pub fn drain_sub_tasks(
&mut self,
task_id: TaskId,
) -> impl Future<Output = SubTaskOutput> + Send + 'static {
let sub_tasks = self
.tasks
.get_mut(&task_id)
.map(|task| (task.drain_sub_tasks(), Arc::clone(&self.context_name)));
async move {
if let Some((mut sub_tasks, context_name)) = sub_tasks {
if !sub_tasks.is_empty() {
gst_log!(
RUNTIME_CAT,
"Scheduling draining {} sub tasks from {:?} on '{}'",
sub_tasks.len(),
task_id,
&context_name,
);
for sub_task in sub_tasks.drain(..) {
sub_task.await?;
}
}
}
Ok(())
}
}
}

1
generic/threadshare/src/runtime/mod.rs
View file

@ -31,6 +31,7 @@
//! See this [talk] ([slides]) for a presentation of the motivations and principles,
//! and this [blog post].
//!
//! FIXME change this.
//! Current implementation uses the crate [`tokio`].
//!
//! Most `Element`s implementations should use the high-level features provided by [`PadSrc`] &