Reland: Increase threshold for usage of compute for utf8 decoding on large strings to 50 KB (#64498)
diff --git a/packages/flutter/lib/src/services/asset_bundle.dart b/packages/flutter/lib/src/services/asset_bundle.dart
index e9550a8..1753fc6 100644
--- a/packages/flutter/lib/src/services/asset_bundle.dart
+++ b/packages/flutter/lib/src/services/asset_bundle.dart
@@ -71,11 +71,13 @@
// that the null-handling logic is dead code).
if (data == null)
throw FlutterError('Unable to load asset: $key'); // ignore: dead_code
- if (data.lengthInBytes < 10 * 1024) {
- // 10KB takes about 3ms to parse on a Pixel 2 XL.
- // See: https://github.com/dart-lang/sdk/issues/31954
+ // 50 KB of data should take 2-3 ms to parse on a Moto G4, and about 400 μs
+ // on a Pixel 4.
+ if (data.lengthInBytes < 50 * 1024) {
return utf8.decode(data.buffer.asUint8List());
}
+ // For strings larger than 50 KB, run the computation in an isolate to
+ // avoid causing main thread jank.
return compute(_utf8decode, data, debugLabel: 'UTF8 decode for "$key"');
}
diff --git a/packages/flutter_tools/lib/src/run_hot.dart b/packages/flutter_tools/lib/src/run_hot.dart
index 77a7867..a712bec 100644
--- a/packages/flutter_tools/lib/src/run_hot.dart
+++ b/packages/flutter_tools/lib/src/run_hot.dart
@@ -562,9 +562,11 @@
} on vm_service.RPCError {
// Do nothing, we're already subcribed.
}
+ // Ideally this would wait for kIsolateRunnable, but either this subscription occurs too
+ // late to receive the event, or it is not forwarded for hot restarted isolates.
isolateNotifications.add(
device.vmService.onIsolateEvent.firstWhere((vm_service.Event event) {
- return event.kind == vm_service.EventKind.kIsolateRunnable;
+ return event.kind == vm_service.EventKind.kServiceExtensionAdded;
}),
);
}
