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[BUG] - `termion` event listener is actually blocking
Description
As i discovered in #76, the current termion
key / event listener
is blocking, even though the Poll
trait explicitly says the function should not be blocking.
This effectively means that anyone wanting to use the termion
backend and one custom port OR rely on a tick is basically unable to do so reliably.
Steps to reproduce
- use the
termion
backend - enable the ticker
- fetch all events for a while
- observe no events being generated (including no ticks)
Reproduction script
extern crate tuirealm;
use std::thread;
use std::time::Duration;
use tui::layout::Rect;
use tuirealm::application::PollStrategy;
use tuirealm::command::{Cmd, CmdResult};
use tuirealm::terminal::TerminalBridge;
use tuirealm::{Application, AttrValue, Attribute, Component, Event, EventListenerCfg, Frame, MockComponent, NoUserEvent, Props, State, Sub, SubClause, SubEventClause, Update};
#[derive(Debug, PartialEq)]
pub enum Msg {}
#[derive(Debug, Eq, PartialEq, Clone, Hash)]
pub enum Id {
FIRST
}
pub struct Model {
pub app: Application<Id, Msg, NoUserEvent>,
pub terminal: TerminalBridge,
}
impl Default for Model {
fn default() -> Self {
Self {
app: Self::init_app(),
terminal: TerminalBridge::new().expect("Cannot initialize terminal"),
}
}
}
impl Model {
fn init_app() -> Application<Id, Msg, NoUserEvent> {
let app: Application<Id, Msg, NoUserEvent> = Application::init(
EventListenerCfg::default()
.default_input_listener(Duration::from_millis(20))
.poll_timeout(Duration::from_millis(10))
.tick_interval(Duration::from_secs(1)),
);
app
}
}
impl Update<Msg> for Model {
fn update(&mut self, msg: Option<Msg>) -> Option<Msg> {
None
}
}
pub struct Label {
props: Props,
}
impl Default for Label {
fn default() -> Self {
Self {
props: Props::default(),
}
}
}
impl MockComponent for Label {
fn view(&mut self, frame: &mut Frame, area: Rect) {
}
fn query(&self, attr: Attribute) -> Option<AttrValue> {
self.props.get(attr)
}
fn attr(&mut self, attr: Attribute, value: AttrValue) {
self.props.set(attr, value);
}
fn state(&self) -> State {
State::None
}
fn perform(&mut self, _: Cmd) -> CmdResult {
CmdResult::None
}
}
impl Component<Msg, NoUserEvent> for Label {
fn on(&mut self, msg: Event<NoUserEvent>) -> Option<Msg> {
println!("Message: {:#?}", msg);
None
}
}
fn main() {
let mut model = Model::default();
// let _ = model.terminal.enter_alternate_screen();
// let _ = model.terminal.enable_raw_mode(); // does nothing on termion
let _ = model.app.mount(Id::FIRST, Box::new(Label::default()), vec![
Sub::new(
SubEventClause::Any,
SubClause::Always,
),
]);
loop {
// Tick
match model.app.tick(PollStrategy::Once) {
Err(err) => {
eprintln!("ERROR: {:#?}", err);
break;
}
Ok(messages) => {
eprintln!("After Tick");
}
}
thread::sleep(Duration::from_secs(1));
}
// let _ = model.terminal.leave_alternate_screen();
// let _ = model.terminal.disable_raw_mode();
// let _ = model.terminal.clear_screen();
}
Log output + some tuirealm inner logs
Note that this is the output over multiple seconds, where a tick should happen every second
LOOP
TERMION WAIT
After Tick
After Tick
After Tick
After Tick
After Tick
After Tick
After Tick
After Tick
After Tick
After Tick
Note that there is no Message: Tick
Git Diff
diff --git a/Cargo.toml b/Cargo.toml
index 17cd154..a4ea2f3 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -48,3 +48,7 @@ path = "examples/demo/demo.rs"
[[example]]
name = "user-events"
path = "examples/user_events/user_events.rs"
+
+[[example]]
+name = "termion-test"
+path = "examples/demo copy/termion-test.rs"
diff --git a/examples/demo copy/termion-test.rs b/examples/demo copy/termion-test.rs
new file mode 100644
index 0000000..2d815a0
--- /dev/null
+++ b/examples/demo copy/termion-test.rs
@@ -0,0 +1,127 @@
+extern crate tuirealm;
+
+use std::thread;
+use std::time::Duration;
+
+use tui::layout::Rect;
+use tuirealm::application::PollStrategy;
+use tuirealm::command::{Cmd, CmdResult};
+use tuirealm::terminal::TerminalBridge;
+use tuirealm::{Application, AttrValue, Attribute, Component, Event, EventListenerCfg, Frame, MockComponent, NoUserEvent, Props, State, Sub, SubClause, SubEventClause, Update};
+
+#[derive(Debug, PartialEq)]
+pub enum Msg {}
+
+#[derive(Debug, Eq, PartialEq, Clone, Hash)]
+pub enum Id {
+ FIRST
+}
+
+pub struct Model {
+ pub app: Application<Id, Msg, NoUserEvent>,
+ pub terminal: TerminalBridge,
+}
+
+impl Default for Model {
+ fn default() -> Self {
+ Self {
+ app: Self::init_app(),
+ terminal: TerminalBridge::new().expect("Cannot initialize terminal"),
+ }
+ }
+}
+
+impl Model {
+ fn init_app() -> Application<Id, Msg, NoUserEvent> {
+ let app: Application<Id, Msg, NoUserEvent> = Application::init(
+ EventListenerCfg::default()
+ .default_input_listener(Duration::from_millis(20))
+ .poll_timeout(Duration::from_millis(10))
+ .tick_interval(Duration::from_secs(1)),
+ );
+ app
+ }
+}
+
+impl Update<Msg> for Model {
+ fn update(&mut self, msg: Option<Msg>) -> Option<Msg> {
+ None
+ }
+}
+
+pub struct Label {
+ props: Props,
+}
+
+impl Default for Label {
+ fn default() -> Self {
+ Self {
+ props: Props::default(),
+ }
+ }
+}
+
+impl MockComponent for Label {
+ fn view(&mut self, frame: &mut Frame, area: Rect) {
+
+ }
+
+ fn query(&self, attr: Attribute) -> Option<AttrValue> {
+ self.props.get(attr)
+ }
+
+ fn attr(&mut self, attr: Attribute, value: AttrValue) {
+ self.props.set(attr, value);
+ }
+
+ fn state(&self) -> State {
+ State::None
+ }
+
+ fn perform(&mut self, _: Cmd) -> CmdResult {
+ CmdResult::None
+ }
+}
+
+impl Component<Msg, NoUserEvent> for Label {
+ fn on(&mut self, msg: Event<NoUserEvent>) -> Option<Msg> {
+ println!("Message: {:#?}", msg);
+
+ None
+ }
+}
+
+fn main() {
+ let mut model = Model::default();
+ // let _ = model.terminal.enter_alternate_screen();
+ // let _ = model.terminal.enable_raw_mode(); // does nothing on termion
+
+ let _ = model.app.mount(Id::FIRST, Box::new(Label::default()), vec![
+ Sub::new(
+ SubEventClause::Any,
+ SubClause::Always,
+ ),
+ ]);
+
+ loop {
+ // Tick
+ match model.app.tick(PollStrategy::Once) {
+ Err(err) => {
+ eprintln!("ERROR: {:#?}", err);
+ break;
+ }
+ Ok(messages) => {
+ eprintln!("After Tick");
+ }
+ }
+
+ thread::sleep(Duration::from_secs(1));
+ }
+ // let _ = model.terminal.leave_alternate_screen();
+ // let _ = model.terminal.disable_raw_mode();
+ // let _ = model.terminal.clear_screen();
+}
diff --git a/src/adapter/termion/listener.rs b/src/adapter/termion/listener.rs
index 117b930..18f5504 100644
--- a/src/adapter/termion/listener.rs
+++ b/src/adapter/termion/listener.rs
@@ -35,6 +35,7 @@ where
U: Eq + PartialEq + Clone + PartialOrd + Send + 'static,
{
fn poll(&mut self) -> ListenerResult<Option<Event<U>>> {
+ eprintln!("TERMION WAIT");
match stdin().events().next() {
Some(Ok(ev)) => Ok(Some(Event::from(ev))),
Some(Err(_)) => Err(ListenerError::PollFailed),
diff --git a/src/listener/worker.rs b/src/listener/worker.rs
index 165f76c..aea6bf6 100644
--- a/src/listener/worker.rs
+++ b/src/listener/worker.rs
@@ -152,6 +152,7 @@ where
/// thread run method
pub(super) fn run(&mut self) {
loop {
+ eprintln!("LOOP");
// Check if running or send_error has occurred
if !self.running() {
break;
@@ -165,6 +166,7 @@ where
if self.poll().is_err() {
break;
}
+ eprintln!("AFTER POLL");
// Tick
if self.should_tick() && self.send_tick().is_err() {
break;
cmd: cargo run --example=termion-test --no-default-features --features=tui,termion
Expected behaviour
termion
to not be blocking
Environment
- OS: Linux Manjaro 24.1.4
- Architecture x86_64
- Rust version: 1.78
- tui-realm version: 40ee05cded197625f234abea6c6be91470f911e7
Additional information
Also from what i can tell, termion
does not provide any way to do this non-blockingly, either requiring to be completely removed or be put into a separate thread
slight update a day later: updated the script as i had noticed that the key events were only going to the components directly, not returned from .poll
; this does not change result though that termion
is still blocking