gstreamer: Add TaskPool bindings and subclassing

Fixes: https://gitlab.freedesktop.org/gstreamer/gstreamer-rs/-/issues/14
This commit is contained in:
Jan Alexander Steffens (heftig) 2021-10-22 15:51:21 +02:00
parent 44b2eba600
commit b7afdd4dd0
No known key found for this signature in database
GPG key ID: 3B94A80E50A477C7
8 changed files with 724 additions and 0 deletions

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@ -2300,6 +2300,42 @@ manual_traits = ["TagSetterExtManual"]
# Takes a raw pointer # Takes a raw pointer
ignore = true ignore = true
[[object]]
name = "Gst.Task"
status = "generate"
# Need work
[[object.function]]
name = "new"
ignore = true
[[object.function]]
name = "set_enter_callback"
ignore = true
[[object.function]]
name = "set_leave_callback"
ignore = true
[[object.function]]
name = "set_lock"
ignore = true
[[object.function]]
name = "set_state"
ignore = true
[[object]]
name = "Gst.TaskPool"
status = "generate"
manual_traits = ["TaskPoolExtManual"]
[[object.function]]
name = "push"
manual = true
# Moved to TaskHandle
[[object.function]]
name = "join"
ignore = true
[[object.function]]
name = "dispose_handle"
ignore = true
[[object]] [[object]]
name = "Gst.Toc" name = "Gst.Toc"
status = "manual" status = "manual"

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@ -95,6 +95,12 @@ pub use self::system_clock::SystemClock;
mod tag_setter; mod tag_setter;
pub use self::tag_setter::TagSetter; pub use self::tag_setter::TagSetter;
mod task;
pub use self::task::Task;
mod task_pool;
pub use self::task_pool::TaskPool;
mod toc_setter; mod toc_setter;
pub use self::toc_setter::TocSetter; pub use self::toc_setter::TocSetter;
@ -225,6 +231,8 @@ pub mod traits {
pub use super::proxy_pad::ProxyPadExt; pub use super::proxy_pad::ProxyPadExt;
pub use super::system_clock::SystemClockExt; pub use super::system_clock::SystemClockExt;
pub use super::tag_setter::TagSetterExt; pub use super::tag_setter::TagSetterExt;
pub use super::task::TaskExt;
pub use super::task_pool::TaskPoolExt;
pub use super::toc_setter::TocSetterExt; pub use super::toc_setter::TocSetterExt;
pub use super::tracer::TracerExt; pub use super::tracer::TracerExt;
pub use super::uri_handler::URIHandlerExt; pub use super::uri_handler::URIHandlerExt;

105
gstreamer/src/auto/task.rs Normal file
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@ -0,0 +1,105 @@
// This file was generated by gir (https://github.com/gtk-rs/gir)
// from gir-files (https://github.com/gtk-rs/gir-files)
// from gst-gir-files (https://gitlab.freedesktop.org/gstreamer/gir-files-rs.git)
// DO NOT EDIT
use crate::Object;
use crate::TaskPool;
use crate::TaskState;
use glib::object::IsA;
use glib::translate::*;
glib::wrapper! {
#[doc(alias = "GstTask")]
pub struct Task(Object<ffi::GstTask, ffi::GstTaskClass>) @extends Object;
match fn {
type_ => || ffi::gst_task_get_type(),
}
}
impl Task {
pub const NONE: Option<&'static Task> = None;
#[doc(alias = "gst_task_cleanup_all")]
pub fn cleanup_all() {
assert_initialized_main_thread!();
unsafe {
ffi::gst_task_cleanup_all();
}
}
}
unsafe impl Send for Task {}
unsafe impl Sync for Task {}
pub trait TaskExt: 'static {
#[doc(alias = "gst_task_get_pool")]
#[doc(alias = "get_pool")]
fn pool(&self) -> TaskPool;
#[doc(alias = "gst_task_get_state")]
#[doc(alias = "get_state")]
fn state(&self) -> TaskState;
#[doc(alias = "gst_task_join")]
fn join(&self) -> bool;
#[doc(alias = "gst_task_pause")]
fn pause(&self) -> bool;
#[cfg(any(feature = "v1_18", feature = "dox"))]
#[cfg_attr(feature = "dox", doc(cfg(feature = "v1_18")))]
#[doc(alias = "gst_task_resume")]
fn resume(&self) -> bool;
#[doc(alias = "gst_task_set_pool")]
fn set_pool(&self, pool: &impl IsA<TaskPool>);
#[doc(alias = "gst_task_start")]
fn start(&self) -> bool;
#[doc(alias = "gst_task_stop")]
fn stop(&self) -> bool;
}
impl<O: IsA<Task>> TaskExt for O {
fn pool(&self) -> TaskPool {
unsafe { from_glib_full(ffi::gst_task_get_pool(self.as_ref().to_glib_none().0)) }
}
fn state(&self) -> TaskState {
unsafe { from_glib(ffi::gst_task_get_state(self.as_ref().to_glib_none().0)) }
}
fn join(&self) -> bool {
unsafe { from_glib(ffi::gst_task_join(self.as_ref().to_glib_none().0)) }
}
fn pause(&self) -> bool {
unsafe { from_glib(ffi::gst_task_pause(self.as_ref().to_glib_none().0)) }
}
#[cfg(any(feature = "v1_18", feature = "dox"))]
#[cfg_attr(feature = "dox", doc(cfg(feature = "v1_18")))]
fn resume(&self) -> bool {
unsafe { from_glib(ffi::gst_task_resume(self.as_ref().to_glib_none().0)) }
}
fn set_pool(&self, pool: &impl IsA<TaskPool>) {
unsafe {
ffi::gst_task_set_pool(
self.as_ref().to_glib_none().0,
pool.as_ref().to_glib_none().0,
);
}
}
fn start(&self) -> bool {
unsafe { from_glib(ffi::gst_task_start(self.as_ref().to_glib_none().0)) }
}
fn stop(&self) -> bool {
unsafe { from_glib(ffi::gst_task_stop(self.as_ref().to_glib_none().0)) }
}
}

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@ -0,0 +1,65 @@
// This file was generated by gir (https://github.com/gtk-rs/gir)
// from gir-files (https://github.com/gtk-rs/gir-files)
// from gst-gir-files (https://gitlab.freedesktop.org/gstreamer/gir-files-rs.git)
// DO NOT EDIT
use crate::Object;
use glib::object::IsA;
use glib::translate::*;
use std::ptr;
glib::wrapper! {
#[doc(alias = "GstTaskPool")]
pub struct TaskPool(Object<ffi::GstTaskPool, ffi::GstTaskPoolClass>) @extends Object;
match fn {
type_ => || ffi::gst_task_pool_get_type(),
}
}
impl TaskPool {
pub const NONE: Option<&'static TaskPool> = None;
#[doc(alias = "gst_task_pool_new")]
pub fn new() -> TaskPool {
assert_initialized_main_thread!();
unsafe { from_glib_full(ffi::gst_task_pool_new()) }
}
}
impl Default for TaskPool {
fn default() -> Self {
Self::new()
}
}
unsafe impl Send for TaskPool {}
unsafe impl Sync for TaskPool {}
pub trait TaskPoolExt: 'static {
#[doc(alias = "gst_task_pool_cleanup")]
fn cleanup(&self);
#[doc(alias = "gst_task_pool_prepare")]
fn prepare(&self) -> Result<(), glib::Error>;
}
impl<O: IsA<TaskPool>> TaskPoolExt for O {
fn cleanup(&self) {
unsafe {
ffi::gst_task_pool_cleanup(self.as_ref().to_glib_none().0);
}
}
fn prepare(&self) -> Result<(), glib::Error> {
unsafe {
let mut error = ptr::null_mut();
let _ = ffi::gst_task_pool_prepare(self.as_ref().to_glib_none().0, &mut error);
if error.is_null() {
Ok(())
} else {
Err(from_glib_full(error))
}
}
}
}

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@ -182,11 +182,13 @@ mod control_source;
mod parse_context; mod parse_context;
mod proxy_pad; mod proxy_pad;
mod tag_setter; mod tag_setter;
mod task_pool;
pub use crate::element::{ElementMessageType, NotifyWatchId}; pub use crate::element::{ElementMessageType, NotifyWatchId};
pub use crate::element::{ pub use crate::element::{
ELEMENT_METADATA_AUTHOR, ELEMENT_METADATA_DESCRIPTION, ELEMENT_METADATA_DOC_URI, ELEMENT_METADATA_AUTHOR, ELEMENT_METADATA_DESCRIPTION, ELEMENT_METADATA_DOC_URI,
ELEMENT_METADATA_ICON_NAME, ELEMENT_METADATA_KLASS, ELEMENT_METADATA_LONGNAME, ELEMENT_METADATA_ICON_NAME, ELEMENT_METADATA_KLASS, ELEMENT_METADATA_LONGNAME,
}; };
pub use crate::task_pool::{TaskHandle, TaskPoolTaskHandle};
pub use self::iterator::{Iterator, IteratorError, IteratorImpl, StdIterator}; pub use self::iterator::{Iterator, IteratorError, IteratorImpl, StdIterator};
pub use crate::clock_time::ClockTime; pub use crate::clock_time::ClockTime;
@ -321,6 +323,7 @@ pub mod prelude {
pub use crate::plugin_feature::PluginFeatureExtManual; pub use crate::plugin_feature::PluginFeatureExtManual;
pub use crate::proxy_pad::ProxyPadExtManual; pub use crate::proxy_pad::ProxyPadExtManual;
pub use crate::tag_setter::TagSetterExtManual; pub use crate::tag_setter::TagSetterExtManual;
pub use crate::task_pool::{TaskHandle, TaskPoolExtManual};
pub use crate::typefind::TypeFindImpl; pub use crate::typefind::TypeFindImpl;
pub use crate::value::GstValueExt; pub use crate::value::GstValueExt;

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@ -24,6 +24,7 @@ mod object;
mod pad; mod pad;
mod pipeline; mod pipeline;
mod proxy_pad; mod proxy_pad;
mod task_pool;
mod tracer; mod tracer;
mod device; mod device;
@ -61,6 +62,7 @@ pub mod prelude {
pub use super::proxy_pad::ProxyPadImpl; pub use super::proxy_pad::ProxyPadImpl;
pub use super::system_clock::SystemClockImpl; pub use super::system_clock::SystemClockImpl;
pub use super::tag_setter::TagSetterImpl; pub use super::tag_setter::TagSetterImpl;
pub use super::task_pool::TaskPoolImpl;
pub use super::tracer::{TracerHook, TracerImpl, TracerImplExt}; pub use super::tracer::{TracerHook, TracerImpl, TracerImplExt};
pub use super::uri_handler::{URIHandlerImpl, URIHandlerImplExt}; pub use super::uri_handler::{URIHandlerImpl, URIHandlerImplExt};
} }

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@ -0,0 +1,347 @@
// Take a look at the license at the top of the repository in the LICENSE file.
use super::prelude::*;
use crate::{TaskHandle, TaskPool};
use std::hash::{Hash, Hasher};
use std::ptr;
use std::sync::{Arc, Mutex};
use glib::ffi::gpointer;
use glib::prelude::*;
use glib::subclass::prelude::*;
use glib::translate::*;
pub trait TaskPoolImpl: GstObjectImpl + Send + Sync {
// rustdoc-stripper-ignore-next
/// Handle to be returned from the `push` function to allow the caller to wait for the task's
/// completion.
///
/// If unneeded, you can specify `()` or [`Infallible`](std::convert::Infallible) for a handle
/// that does nothing on `join` or drop.
type Handle: TaskHandle;
// rustdoc-stripper-ignore-next
/// Prepare the task pool to accept tasks.
///
/// This defaults to doing nothing.
fn prepare(&self, _task_pool: &Self::Type) -> Result<(), glib::Error> {
Ok(())
}
// rustdoc-stripper-ignore-next
/// Clean up, rejecting further tasks and waiting for all accepted tasks to be stopped.
///
/// This is mainly used internally to ensure proper cleanup of internal data structures in test
/// suites.
fn cleanup(&self, _task_pool: &Self::Type) {}
// rustdoc-stripper-ignore-next
/// Deliver a task to the pool.
///
/// If returning `Ok`, you need to call the `func` eventually.
///
/// If returning `Err`, the `func` must be dropped without calling it.
fn push(
&self,
task_pool: &Self::Type,
func: TaskPoolFunction,
) -> Result<Option<Self::Handle>, glib::Error>;
}
unsafe impl<T: TaskPoolImpl> IsSubclassable<T> for TaskPool {
fn class_init(klass: &mut glib::Class<Self>) {
Self::parent_class_init::<T>(klass);
let klass = klass.as_mut();
klass.prepare = Some(task_pool_prepare::<T>);
klass.cleanup = Some(task_pool_cleanup::<T>);
klass.push = Some(task_pool_push::<T>);
klass.join = Some(task_pool_join::<T>);
#[cfg(any(feature = "v1_20", feature = "dox"))]
{
klass.dispose_handle = Some(task_pool_dispose_handle::<T>);
}
}
}
unsafe extern "C" fn task_pool_prepare<T: TaskPoolImpl>(
ptr: *mut ffi::GstTaskPool,
error: *mut *mut glib::ffi::GError,
) {
let instance = &*(ptr as *mut T::Instance);
let imp = instance.imp();
let wrap: Borrowed<TaskPool> = from_glib_borrow(ptr);
match imp.prepare(wrap.unsafe_cast_ref()) {
Ok(()) => {}
Err(err) => {
if !error.is_null() {
*error = err.into_raw();
}
}
}
}
unsafe extern "C" fn task_pool_cleanup<T: TaskPoolImpl>(ptr: *mut ffi::GstTaskPool) {
let instance = &*(ptr as *mut T::Instance);
let imp = instance.imp();
let wrap: Borrowed<TaskPool> = from_glib_borrow(ptr);
imp.cleanup(wrap.unsafe_cast_ref());
}
unsafe extern "C" fn task_pool_push<T: TaskPoolImpl>(
ptr: *mut ffi::GstTaskPool,
func: ffi::GstTaskPoolFunction,
user_data: gpointer,
error: *mut *mut glib::ffi::GError,
) -> gpointer {
let instance = &*(ptr as *mut T::Instance);
let imp = instance.imp();
let wrap: Borrowed<TaskPool> = from_glib_borrow(ptr);
let func = TaskPoolFunction::new(func.expect("Tried to push null func"), user_data);
match imp.push(wrap.unsafe_cast_ref(), func.clone()) {
Ok(None) => ptr::null_mut(),
Ok(Some(handle)) => Box::into_raw(Box::new(handle)) as gpointer,
Err(err) => {
func.prevent_call();
if !error.is_null() {
*error = err.into_raw();
}
ptr::null_mut()
}
}
}
unsafe extern "C" fn task_pool_join<T: TaskPoolImpl>(ptr: *mut ffi::GstTaskPool, id: gpointer) {
let wrap: Borrowed<TaskPool> = from_glib_borrow(ptr);
if id.is_null() {
crate::warning!(crate::CAT_RUST, obj: wrap.as_ref(), "Tried to join null handle");
return;
}
let handle = Box::from_raw(id as *mut T::Handle);
handle.join();
}
#[cfg(any(feature = "v1_20", feature = "dox"))]
#[cfg_attr(feature = "dox", doc(cfg(feature = "v1_20")))]
unsafe extern "C" fn task_pool_dispose_handle<T: TaskPoolImpl>(
ptr: *mut ffi::GstTaskPool,
id: gpointer,
) {
let wrap: Borrowed<TaskPool> = from_glib_borrow(ptr);
if id.is_null() {
crate::warning!(crate::CAT_RUST, obj: wrap.as_ref(), "Tried to dispose null handle");
return;
}
let handle = Box::from_raw(id as *mut T::Handle);
drop(handle);
}
// rustdoc-stripper-ignore-next
/// Function the task pool should execute, provided to [`push`](TaskPoolImpl::push).
#[derive(Debug)]
pub struct TaskPoolFunction(Arc<Mutex<Option<TaskPoolFunctionInner>>>);
// `Arc<Mutex<Option<…>>>` is required so that we can enforce that the function
// has not been called and will never be called after `push` returns `Err`.
#[derive(Debug)]
struct TaskPoolFunctionInner {
func: unsafe extern "C" fn(gpointer),
user_data: gpointer,
warn_on_drop: bool,
}
unsafe impl Send for TaskPoolFunctionInner {}
impl TaskPoolFunction {
fn new(func: unsafe extern "C" fn(gpointer), user_data: gpointer) -> Self {
let inner = TaskPoolFunctionInner {
func,
user_data,
warn_on_drop: true,
};
Self(Arc::new(Mutex::new(Some(inner))))
}
fn clone(&self) -> Self {
Self(self.0.clone())
}
// rustdoc-stripper-ignore-next
/// Consume and execute the function.
pub fn call(self) {
let mut inner = self
.0
.lock()
.unwrap()
.take()
.expect("TaskPoolFunction has already been dropped");
inner.warn_on_drop = false;
unsafe { (inner.func)(inner.user_data) }
}
fn prevent_call(self) {
let mut inner = self
.0
.lock()
.unwrap()
.take()
.expect("TaskPoolFunction has already been called");
inner.warn_on_drop = false;
drop(inner);
}
fn as_ptr(&self) -> *const Mutex<Option<TaskPoolFunctionInner>> {
Arc::as_ptr(&self.0)
}
}
impl Drop for TaskPoolFunctionInner {
fn drop(&mut self) {
if self.warn_on_drop {
crate::warning!(crate::CAT_RUST, "Leaked task function");
}
}
}
impl PartialEq for TaskPoolFunction {
fn eq(&self, other: &Self) -> bool {
self.as_ptr() == other.as_ptr()
}
}
impl Eq for TaskPoolFunction {}
impl PartialOrd for TaskPoolFunction {
fn partial_cmp(&self, other: &Self) -> Option<std::cmp::Ordering> {
self.as_ptr().partial_cmp(&other.as_ptr())
}
}
impl Ord for TaskPoolFunction {
fn cmp(&self, other: &Self) -> std::cmp::Ordering {
self.as_ptr().cmp(&other.as_ptr())
}
}
impl Hash for TaskPoolFunction {
fn hash<H: Hasher>(&self, state: &mut H) {
self.as_ptr().hash(state)
}
}
#[cfg(test)]
mod tests {
use super::*;
use crate::prelude::*;
use std::sync::atomic;
use std::sync::mpsc::{channel, TryRecvError};
use std::thread;
pub mod imp {
use super::*;
#[derive(Default)]
pub struct TestPool {
pub(super) prepared: atomic::AtomicBool,
pub(super) cleaned_up: atomic::AtomicBool,
}
#[glib::object_subclass]
impl ObjectSubclass for TestPool {
const NAME: &'static str = "TestPool";
type Type = super::TestPool;
type ParentType = TaskPool;
}
impl ObjectImpl for TestPool {}
impl GstObjectImpl for TestPool {}
impl TaskPoolImpl for TestPool {
type Handle = TestHandle;
fn prepare(&self, _task_pool: &Self::Type) -> Result<(), glib::Error> {
self.prepared.store(true, atomic::Ordering::SeqCst);
Ok(())
}
fn cleanup(&self, _task_pool: &Self::Type) {
self.cleaned_up.store(true, atomic::Ordering::SeqCst);
}
fn push(
&self,
_task_pool: &Self::Type,
func: TaskPoolFunction,
) -> Result<Option<Self::Handle>, glib::Error> {
let handle = thread::spawn(move || func.call());
Ok(Some(TestHandle(handle)))
}
}
pub struct TestHandle(thread::JoinHandle<()>);
impl TaskHandle for TestHandle {
fn join(self) {
self.0.join().unwrap();
}
}
}
glib::wrapper! {
pub struct TestPool(ObjectSubclass<imp::TestPool>) @extends TaskPool, crate::Object;
}
unsafe impl Send for TestPool {}
unsafe impl Sync for TestPool {}
impl TestPool {
pub fn new() -> Self {
Self::default()
}
}
impl Default for TestPool {
fn default() -> Self {
glib::Object::new(&[]).unwrap()
}
}
#[test]
fn test_simple_subclass() {
crate::init().unwrap();
let pool = TestPool::new();
pool.prepare().unwrap();
let (sender, receiver) = channel();
let handle = pool
.push(move || {
sender.send(()).unwrap();
})
.unwrap();
let handle = handle.unwrap();
assert_eq!(receiver.recv(), Ok(()));
handle.join();
assert_eq!(receiver.try_recv(), Err(TryRecvError::Disconnected));
pool.cleanup();
let imp = imp::TestPool::from_instance(&pool);
assert!(imp.prepared.load(atomic::Ordering::SeqCst));
assert!(imp.cleaned_up.load(atomic::Ordering::SeqCst));
}
}

158
gstreamer/src/task_pool.rs Normal file
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@ -0,0 +1,158 @@
// Take a look at the license at the top of the repository in the LICENSE file.
use crate::TaskPool;
use std::ptr;
use glib::ffi::gpointer;
use glib::prelude::*;
use glib::translate::*;
unsafe extern "C" fn task_pool_trampoline<P: FnOnce() + Send + 'static>(data: gpointer) {
let func = Box::from_raw(data as *mut P);
func()
}
pub trait TaskPoolExtManual: 'static {
#[doc(alias = "gst_task_pool_push")]
fn push<P: FnOnce() + Send + 'static>(
&self,
func: P,
) -> Result<Option<TaskPoolTaskHandle>, glib::Error>;
}
impl<O: IsA<TaskPool>> TaskPoolExtManual for O {
fn push<P: FnOnce() + Send + 'static>(
&self,
func: P,
) -> Result<Option<TaskPoolTaskHandle>, glib::Error> {
unsafe {
let mut error = ptr::null_mut();
let func: Box<P> = Box::new(func);
let func = Box::into_raw(func);
let handle = ffi::gst_task_pool_push(
self.as_ref().to_glib_none().0,
Some(task_pool_trampoline::<P>),
func as gpointer,
&mut error,
);
if !error.is_null() {
assert!(handle.is_null());
// Assume that task_pool_trampoline was
// not called and will not be called
drop(Box::from_raw(func));
return Err(from_glib_full(error));
}
let handle = ptr::NonNull::new(handle).map(|handle| TaskPoolTaskHandle {
handle,
task_pool: Some(self.as_ref().clone()),
});
Ok(handle)
}
}
}
impl TaskPool {
unsafe fn join(&self, id: ptr::NonNull<libc::c_void>) {
ffi::gst_task_pool_join(self.to_glib_none().0, id.as_ptr())
}
#[cfg(any(feature = "v1_20", feature = "dox"))]
#[cfg_attr(feature = "dox", doc(cfg(feature = "v1_20")))]
unsafe fn dispose_handle(&self, id: ptr::NonNull<libc::c_void>) {
ffi::gst_task_pool_dispose_handle(self.to_glib_none().0, id.as_ptr())
}
}
// rustdoc-stripper-ignore-next
/// A handle for a task which was pushed to a task pool.
pub trait TaskHandle {
// rustdoc-stripper-ignore-next
/// Wait for the task to complete.
fn join(self);
}
impl TaskHandle for () {
fn join(self) {}
}
impl TaskHandle for std::convert::Infallible {
fn join(self) {}
}
// rustdoc-stripper-ignore-next
/// An opaque handle for a task associated with a particular task pool.
///
/// Keeps a reference to the pool alive.
///
/// If the `v1_20` feature is enabled, requests the task pool to dispose of the handle when it is
/// dropped. Otherwise, needs to be `join`ed to avoid a leak.
#[cfg_attr(not(any(feature = "v1_20", feature = "dox")), must_use)]
#[derive(Debug, PartialEq, Eq, PartialOrd, Ord, Hash)]
pub struct TaskPoolTaskHandle {
handle: ptr::NonNull<libc::c_void>,
task_pool: Option<TaskPool>,
}
impl TaskHandle for TaskPoolTaskHandle {
#[doc(alias = "gst_task_pool_join")]
fn join(mut self) {
let task_pool = self.task_pool.take().unwrap();
unsafe { task_pool.join(self.handle) }
}
}
impl Drop for TaskPoolTaskHandle {
#[doc(alias = "gst_task_pool_dispose_handle")]
fn drop(&mut self) {
if let Some(task_pool) = self.task_pool.take() {
cfg_if::cfg_if! {
if #[cfg(any(feature = "v1_20", feature = "dox"))] {
unsafe { task_pool.dispose_handle(self.handle) }
} else {
crate::warning!(crate::CAT_RUST, obj: &task_pool, "Leaked task handle");
}
}
}
}
}
#[cfg(test)]
mod tests {
use super::*;
use crate::prelude::*;
use std::sync::mpsc::{channel, RecvError};
#[test]
fn test_simple() {
crate::init().unwrap();
let pool = TaskPool::new();
pool.prepare().unwrap();
let (sender, receiver) = channel();
let handle = pool
.push(move || {
sender.send(()).unwrap();
})
.unwrap();
assert_eq!(receiver.recv(), Ok(()));
if let Some(handle) = handle {
handle.join();
}
// Can't test try_recv here as the default task pool produces no
// handles and thus no way to wait for channel destruction
assert_eq!(receiver.recv(), Err(RecvError));
pool.cleanup();
}
}