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perf: many-webviews stress harness + Metal dst-texture cache + leak/fd robustness #11

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Merged
wenkaifan0720 merged 5 commits into from
Jun 25, 2026
Merged

perf: many-webviews stress harness + Metal dst-texture cache + leak/fd robustness #11

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b71ca93
test(perf): add a many-webviews stress probe + process/RSS/fd/cpu sam…
wenkaifan0720 Jun 24, 2026
a209d36
perf(cef_host): cache the GPU-blit dest MTLTexture per-Slot
wenkaifan0720 Jun 24, 2026
9ed574b
fix(cef): SIGKILL+reap a wedged host on death; raise RLIMIT_NOFILE at…
wenkaifan0720 Jun 24, 2026
e58b8ed
perf(osr): never-blank serialized establishment + faster cascade + zo…
wenkaifan0720 Jun 25, 2026
665ea51
Merge remote-tracking branch 'origin/main' into dig/perf-render
wenkaifan0720 Jun 25, 2026
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129 changes: 129 additions & 0 deletions example/lib/crispness_probe.dart
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Original file line number Diff line number Diff line change
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// Crispness probe — verifies renderScale keeps an OSR webview sharp when the view
// is visually SCALED by an ancestor transform (the infinite-canvas zoom case).
//
// A single CefWebView is wrapped in a Transform.scale to mimic a canvas zoom: the
// widget's logical size is unchanged, the transform just magnifies it. Without
// renderScale the OSR buffer stays at 1x-zoom resolution and the transform upscales
// it (blurry); with renderScale = screenDpr * zoom the page re-renders at the
// on-screen pixel density (crisp).
//
// Controls: + / - zoom in/out; R toggle renderScale (crisp) vs none (blurry).
//
// Run:
// FLUTTER_CEF_HOST=<.../cef_host> FLUTTER_CEF_ALLOW_INSECURE_PROFILE=1 \
// flutter run -d macos -t lib/crispness_probe.dart
import 'package:flutter/material.dart';
import 'package:flutter_cef/flutter_cef.dart';

// A text-heavy page — blur shows up most clearly on small text + thin rules.
const _textHtml = '''<!doctype html><meta charset="utf-8">
<body style="margin:0;font:13px/1.5 -apple-system,system-ui;padding:16px;color:#111">
<h1 style="font-size:20px">Crispness test</h1>
<p>The quick brown fox jumps over the lazy dog. 0123456789.
Small text and <a href="#">thin hairlines</a> reveal upscaling blur.</p>
<hr>
<p style="font-size:11px">Zoom in: with renderScale this text re-rasterizes sharp;
without it, the 1x texture is magnified and goes soft.</p>
<table border=1 cellspacing=0 cellpadding=4 style="border-collapse:collapse;font-size:11px">
<tr><th>Col A</th><th>Col B</th><th>Col C</th></tr>
<tr><td>row 1</td><td>1.0</td><td>crisp</td></tr>
<tr><td>row 2</td><td>2.0</td><td>edges</td></tr>
</table>
</body>''';

void main() => runApp(const CrispApp());

class CrispApp extends StatefulWidget {
const CrispApp({super.key});
@override
State<CrispApp> createState() => _CrispAppState();
}

class _CrispAppState extends State<CrispApp> {
final _controller = CefWebController();
double _zoom = 1.0;
bool _crisp = true;

@override
void initState() {
super.initState();
_controller.onPageStarted = (_) => _controller.loadHtmlString(_textHtml);
}

@override
void dispose() {
_controller.dispose();
super.dispose();
}

@override
Widget build(BuildContext context) {
final screenDpr = MediaQuery.maybeOf(context)?.devicePixelRatio ?? 2.0;
// The whole point: when crisp, render at screenDpr*zoom so the buffer has enough
// pixels for the transform's magnification; otherwise leave it at screenDpr (blurry).
final renderScale = _crisp ? screenDpr * _zoom : null;
return MaterialApp(
debugShowCheckedModeBanner: false,
home: Scaffold(
backgroundColor: const Color(0xFF202733),
body: Column(
children: [
Container(
width: double.infinity,
color: const Color(0xFF0B1220),
padding: const EdgeInsets.symmetric(horizontal: 12, vertical: 8),
child: Row(
children: [
Expanded(
child: Text(
'zoom=${_zoom.toStringAsFixed(2)} '
'renderScale=${renderScale?.toStringAsFixed(2) ?? "OFF (blurry)"}',
style: const TextStyle(color: Colors.white),
),
),
_btn('−', () => setState(
() => _zoom = (_zoom - 0.25).clamp(0.5, 4.0))),
const SizedBox(width: 6),
_btn('+', () => setState(
() => _zoom = (_zoom + 0.25).clamp(0.5, 4.0))),
const SizedBox(width: 14),
_btn(_crisp ? 'crisp ✓' : 'blurry',
() => setState(() => _crisp = !_crisp),
wide: true),
],
),
),
Expanded(
child: Center(
// Fixed logical size, magnified by Transform.scale — exactly the
// infinite-canvas case where `size` doesn't change on zoom.
child: Transform.scale(
scale: _zoom,
child: SizedBox(
width: 360,
height: 300,
child: CefWebView(
url: 'about:blank',
controller: _controller,
renderScale: renderScale,
),
),
),
),
),
],
),
),
);
}

Widget _btn(String label, VoidCallback onTap, {bool wide = false}) =>
ElevatedButton(
onPressed: onTap,
style: ElevatedButton.styleFrom(
minimumSize: Size(wide ? 90 : 44, 36),
padding: const EdgeInsets.symmetric(horizontal: 8),
),
child: Text(label),
);
}
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