implement stdout streaming in render_tests::Renderer

[onur-ozkan]

This way, we can show the test dot characters on the console immediately, without having to wait for the entire line to finish.

cc @GuillaumeGomez

[rustbot]

r? @clubby789

(rustbot has picked a reviewer for you, use r? to override)

[onur-ozkan]

Will keep this draft for now. I want to look into render_tests::try_run_test and see if I should fix this there.

[GuillaumeGomez]

Thanks for looking into it in any case!

[onur-ozkan]

I want to look into render_tests::try_run_test and see if I should fix this there.

Yeap, this is much better. Could be useful for other use cases too.

@rustbot ready

[clubby789]

@bors r+

[bors]

📌 Commit 6c966dc has been approved by clubby789

It is now in the queue for this repository.

[klensy]

This way, we can show the test dot characters on the console immediately, without having to wait for the entire line to finish.

But this already works that way, why change anything?

python x.py --stage=1 --jobs=4 test tests/ui/
[cut]
Check compiletest suite=ui mode=ui (x86_64-pc-windows-msvc -> x86_64-pc-windows-msvc)

running 15130 tests
iiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiii    88/15130
iiiiiiiiiiiiiiiiiiiiiiiiiiii............................................................   176/15130
.......iiiiiiiiiiiiiii.....................i..................i....i....................   264/15130
........................................................................................   352/15130
........................................................................................   440/15130
......

[GuillaumeGomez]

Not for rustdoc-gui.

[onur-ozkan]

This way, we can show the test dot characters on the console immediately, without having to wait for the entire line to finish.

But this already works that way, why change anything?

python x.py --stage=1 --jobs=4 test tests/ui/
[cut]
Check compiletest suite=ui mode=ui (x86_64-pc-windows-msvc -> x86_64-pc-windows-msvc)

running 15130 tests
iiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiii    88/15130
iiiiiiiiiiiiiiiiiiiiiiiiiiii............................................................   176/15130
.......iiiiiiiiiiiiiii.....................i..................i....i....................   264/15130
........................................................................................   352/15130
........................................................................................   440/15130
......

rust/src/bootstrap/render_tests.rs

Lines 95 to 118 in 6c966dc

	fn render_all(mut self) {
	let mut line = Vec::new();
	loop {
	line.clear();
	match self.stdout.read_until(b'\n', &mut line) {
	Ok(_) => {}
	Err(err) if err.kind() == std::io::ErrorKind::UnexpectedEof => break,
	Err(err) => panic!("failed to read output of test runner: {err}"),
	}
	if line.is_empty() {
	break;
	}
	match serde_json::from_slice(&line) {
	Ok(parsed) => self.render_message(parsed),
	Err(_err) => {
	// Handle non-JSON output, for example when --nocapture is passed.
	let mut stdout = std::io::stdout();
	stdout.write_all(&line).unwrap();
	let _ = stdout.flush();
	}
	}
	}
	}

this reads the stdout line by line

[klensy]

Ok, in that case what command didn't worked that way before?

[GuillaumeGomez]

All of them (well at least all rustdoc test suites and test/ui).

[klensy]

All of them (well at least all rustdoc test suites and test/ui).

In my case, dots printed one by one and digits printed when dots reach right side, that's why i asked about that change.

[GuillaumeGomez]

rustdoc-gui got migrated recently to a rust test runner and after that change, the dots are only displayed when the line is complete. It's not a problem in itself but it's not great compared to how it was working previously.

[onur-ozkan]

All of them (well at least all rustdoc test suites and test/ui).

In my case, dots printed one by one and digits printed when dots reach right side, that's why i asked about that change.

What is your HEAD ref? Do you have src/tools/rustdoc-gui-test tool in your tree ?

--

After the rustdoc-gui-test tool, we started using render_test::try_run_tests which reads/writes stdout line by line.

[klensy]

What is your HEAD ref? Do you have src/tools/rustdoc-gui-test tool in your tree ?

head is 34d64ab, src/tools/rustdoc-gui-test exist
works on fd0a331. I'll try to clean all and rebuild.

[onur-ozkan]

What is your HEAD ref? Do you have src/tools/rustdoc-gui-test tool in your tree ?

head is 34d64ab, src/tools/rustdoc-gui-test exist

Hmm. By looking to the code, I don't know why it works on your side :)

[klensy]

fd0a331:

python x.py clean
python x.py --stage=1 --jobs=4 test tests/ui/

Still the same, dots perfectly printed one by one.

[onur-ozkan]

Still the same, dots perfectly printed one by one.

try x test rustdoc-gui

[klensy]

Still the same, dots perfectly printed one by one.

try x test rustdoc-gui

Ughh, under windows here multiple issues which prevents this run. Fixed some of them, but looks like browser-ui-test still broken in some way.

[bors]

⌛ Testing commit 6c966dc with merge b963a57...

[klensy]

Ok, it print dots for ./x.ps1 test rustdoc-gui all at once, but for other tests it already worked.

[bors]

☀️ Test successful - checks-actions
Approved by: clubby789
Pushing b963a57 to master...

[rust-timer]

Finished benchmarking commit (b963a57): comparison URL.

Overall result: no relevant changes - no action needed

@rustbot label: -perf-regression

Instruction count

This benchmark run did not return any relevant results for this metric.

Max RSS (memory usage)

Results

This is a less reliable metric that may be of interest but was not used to determine the overall result at the top of this comment.

	mean	range	count
Regressions ❌ (primary)	3.6%	[3.6%, 3.6%]	1
Regressions ❌ (secondary)	-	-	0
Improvements ✅ (primary)	-	-	0
Improvements ✅ (secondary)	-2.7%	[-2.7%, -2.7%]	1
All ❌✅ (primary)	3.6%	[3.6%, 3.6%]	1

Cycles

This benchmark run did not return any relevant results for this metric.

Binary size

This benchmark run did not return any relevant results for this metric.

Bootstrap: 647.661s -> 649.999s (0.36%)