[flutter_tools] Add device log streaming support to DeviceService and ExtensionBackedDevice by bkonyi · Pull Request #194964 · flutter/flutter

bkonyi · 2026-10-21T16:08:10Z

Adds device log streaming support for tool-extension-backed target devices (flutter logs and flutter run console output):

Adds startLogStreamMethod (device.startLogStream), stopLogStreamMethod (device.stopLogStream), logEntryNotificationMethod (device.logEntry), lineKey, startLogStream, stopLogStream, and emitLogLine to DeviceService (package:flutter_tools_extension).
Implements startLogStream and stopLogStream on ExtensionDeviceClient, introduces ExtensionDeviceLogReader, and updates ExtensionBackedDevice.getLogReader to cache and dispose a per-device log reader.
Updates LogsCommand.runCommand() to skip applicationPackages.getPackageForPlatform when targetPlatform == TargetPlatform.unsupported (such as custom-platform extension devices).
Adds hermetic unit and isolate RPC tests in test/general.shard/extension_protocol/extension_device_test.dart and an end-to-end LogsCommand integration test in test/commands.shard/hermetic/tool_extensions_device_test.dart.

Part of #190755
Part of #190750

Pre-launch Checklist

I read the [Contributor Guide] and followed the process outlined there for submitting PRs.
I read the [Tree Hygiene] wiki page, which explains my responsibilities.
I read and followed the [Flutter Style Guide], including [Features we expect every widget to implement].
I signed the [CLA].
I listed at least one issue that this PR fixes in the description above.
I updated/added relevant documentation (doc comments with ///).
I added new tests to check the change I am making, or this PR is [test-exempt].
I followed the [breaking change policy] and added [Data Driven Fixes] where supported.
All existing and new tests are passing.

…n support to tool extension protocol Adds bidirectional JSON-RPC 2.0 notification support (, , and ), sliding inactivity timeout monitoring with progress/heartbeat resets (), and cooperative request cancellation ( and ). Updates to use instead of an unbounded . Part of flutter#190755 Part of flutter#190746 Fixes flutter#193955

… ExtensionBackedDevice Adds device log streaming RPCs (`device.startLogStream` and `device.stopLogStream`) and notification delivery (`device.logEntry`) to `DeviceService`, implements `ExtensionDeviceLogReader`, and updates `ExtensionBackedDevice.getLogReader` to stream logs from tool extension isolates. Part of flutter#190755 Part of flutter#190750

… and post-handshake isolate exit handling Simplifies the extension protocol changes to focus on bidirectional JSON-RPC 2.0 notification support and resilient post-handshake isolate exit and error handling, removing request cancellation and heartbeat APIs. Part of flutter#190755 Part of flutter#190746

…-device-log-streaming # Conflicts: # packages/flutter_tools/packages/flutter_tools_extension/lib/src/protocol_base/provider.dart

…nd isolate exit handling - Log unhandled extension isolate errors using logger.printError instead of trace so failure reasons are visible at default verbosity. - Close receive port, error port, exit port, and notification controllers on unexpected isolate exit. - Validate onNotification payload type and warn on malformed payloads rather than falling back to an empty map. - Strengthen unit test assertions on StateError messages and verify notification streams emit done on unexpected isolate exit. Part of flutter#190755 Part of flutter#190746 Fixes flutter#193955

…-device-log-streaming

…t listeners - Switch _errorPort and _exitPort from RawReceivePort to ReceivePort. - Add _handleIsolateError and _handleIsolateExit helper methods with documentation explaining unhandled error list payloads and unexpected exit handling. - Wire stream listeners in ExtensionConnection.spawn before isolate spawning and dispatch to active connection once created. Part of flutter#190755 Part of flutter#190746

…-device-log-streaming

…e controller cleanup - Delegate unexpected isolate exit handling in _handleIsolateExit to dispose() to centralize resource teardown. - Inline _closeNotificationControllers directly into dispose() as it is the single cleanup path. Part of flutter#190755 Part of flutter#190746

…-device-log-streaming

…gReader and ExtensionBackedDevice - Add async factory ExtensionDeviceLogReader.create that awaits deviceService.startLogStream before returning. - Buffer early log lines until a listener attaches to logLines. - Make ExtensionDeviceLogReader.dispose() asynchronous and await subscription cancellation, stopLogStream, and stream controller closure. - Make ExtensionBackedDevice.getLogReader() return Future<DeviceLogReader> and await reader disposal in dispose(). - Update unit tests to await getLogReader, create, and dispose. Part of flutter#190755 Part of flutter#190746

…isolate exit handling to ExtensionConnection (flutter#194961) Adds extension-to-host JSON-RPC notification support (`ToolExtensionService.sendNotification` and `ExtensionConnection.onNotification`, first consumed by device log streaming in flutter#194964) and keeps `onError`/`onExit` ports open after the handshake so unexpected isolate exits or unhandled errors immediately fail pending `sendRequest(..., timeout: null)` calls and close notification streams instead of hanging forever. Part of flutter#190755 Part of flutter#190746

…treaming # Conflicts: # packages/flutter_tools/packages/flutter_tools_extension/lib/src/device.dart

…ommand integration test Use private named initializers on `ExtensionBackedDevice`, scope `DeviceService.startLogStream` and `ExtensionDeviceLogReader` per `deviceId` without `appId`, revert `protocol_base/provider.dart` so `DeviceService` is not referenced from the base protocol, add explicit `String` type annotations to `DeviceService` constants, close `ExtensionDeviceLogReader.logLines` on isolate exit or startup failure, and guard `LogsCommand` against `TargetPlatform.unsupported` with an end-to-end `LogsCommand` integration test.

gemini-code-assist

Code Review

This pull request implements device log streaming support for tool extension devices, introducing ExtensionDeviceLogReader to stream logs via RPC and updating ExtensionBackedDevice to manage its lifecycle. Feedback focuses on improving robustness and preventing resource leaks, specifically by avoiding private field formals in public constructors, cancelling subscriptions on log stream start failures, preventing log reader creation after disposal, and limiting the buffer size of pending log lines to avoid unbounded memory growth.

…nd guard post-dispose getLogReader Cancel the notification subscription and mark `ExtensionDeviceLogReader` disposed when `startLogStream` fails, cap buffered pending log lines at `_maxPendingLines`, and return a `NoOpDeviceLogReader` if `ExtensionBackedDevice.getLogReader` is called after `dispose()`.

loic-sharma · 2026-10-24T01:08:43Z

+
+/// A [DeviceLogReader] that streams log lines from a tool extension isolate
+/// via [DeviceService.logEntryNotificationMethod] notifications.
+class ExtensionDeviceLogReader extends DeviceLogReader {


I don't love streams. No actions needed, just venting 😂

… ExtensionDevices

…broadcast subscribers

…der initial buffer flush

flutter-dashboard · 2026-10-26T16:20:16Z

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Changes reported for pull request #194964 at sha 2c62460

loic-sharma

LGTM! 👍

flutter/flutter@d4c8577...0c2473c 2026-10-28 [email protected] Roll Packages from a8549ae to 13d38e0 (9 revisions) (flutter/flutter#195488) 2026-10-28 [email protected] Use int.oneBitCount in PersistentHashMap and scope 53-bit caps to JS (flutter/flutter#195005) 2026-10-28 [email protected] Roll pub packages (flutter/flutter#195483) 2026-10-28 [email protected] [iPhone Duo] Use the correct UIScreen to report the display size and update when fold/unfold (flutter/flutter#195199) 2026-10-28 [email protected] [fuchsia] Fix portable_ui_test.h includes for newer Fuchsia SDKs (flutter/flutter#195420) 2026-10-28 [email protected] Change default pipeline options to match production draw calls (flutter/flutter#194597) 2026-10-28 [email protected] Roll Fuchsia Test Scripts from 2T18KC7-LDQtmQiLP... to xl1LWBuppzu-BnOzV... (flutter/flutter#195450) 2026-10-27 [email protected] [flutter_tools] Inject dependencies into Darwin build targets, native assets, and Xcode build settings (flutter/flutter#194052) 2026-10-27 [email protected] Revert: Reland square corners fix (flutter/flutter#195436) 2026-10-27 [email protected] [flutter_tools] Add DeviceService app launch and flutter run support for tool extensions (flutter/flutter#194589) 2026-10-27 [email protected] [engine] Honor targetWidth/targetHeight for animated images (flutter/flutter#194615) 2026-10-27 [email protected] [Android][a11y] Set visibleToUser=false for hidden semantics nodes (flutter/flutter#194411) 2026-10-27 [email protected] Fix repo deletion test flake (flutter/flutter#195349) 2026-10-27 [email protected] Roll Packages from 23a05b6 to a8549ae (10 revisions) (flutter/flutter#195434) 2026-10-27 [email protected] [web] Capture pointers to the Flutter view so drags survive platform view iframes (flutter/flutter#195187) 2026-10-27 [email protected] [web] Add opt-in raw samples, measured sample count and warm-up phase hook to the web benchmark recorder (flutter/flutter#195118) 2026-10-27 [email protected] Link migration guide in deprecation messages (flutter/flutter#195361) 2026-10-27 [email protected] Pin basic_material_app_macos__compile to macOS 26 (flutter/flutter#195429) 2026-10-27 [email protected] Add benchmark for warmed pipeline usage (flutter/flutter#195001) 2026-10-27 [email protected] [flutter_tools] Add device log streaming support to DeviceService and ExtensionBackedDevice (flutter/flutter#194964) 2026-10-27 [email protected] Roll Dart SDK from 1d16c04dc346 to 65fc979759ca (4 revisions) (flutter/flutter#195383) If this roll has caused a breakage, revert this CL and set the roller to dry run mode using the controls here: https://autoroll.skia.org/r/flutter-packages Please CC [email protected],[email protected] on the revert to ensure that a human is aware of the problem. To file a bug in Packages: https://github.com/flutter/flutter/issues/new/choose To report a problem with the AutoRoller itself, please file a bug: https://issues.skia.org/issues/new?component=1389291&template=1850622 Documentation for the AutoRoller is here: https://skia.googlesource.com/buildbot/+doc/main/autoroll/README.md

…isolate exit handling to ExtensionConnection (flutter#194961) Adds extension-to-host JSON-RPC notification support (`ToolExtensionService.sendNotification` and `ExtensionConnection.onNotification`, first consumed by device log streaming in flutter#194964) and keeps `onError`/`onExit` ports open after the handshake so unexpected isolate exits or unhandled errors immediately fail pending `sendRequest(..., timeout: null)` calls and close notification streams instead of hanging forever. Part of flutter#190755 Part of flutter#190746

… ExtensionBackedDevice (flutter#194964) Adds device log streaming support for tool-extension-backed target devices (`flutter logs` and `flutter run` console output): - Adds `startLogStreamMethod` (`device.startLogStream`), `stopLogStreamMethod` (`device.stopLogStream`), `logEntryNotificationMethod` (`device.logEntry`), `lineKey`, `startLogStream`, `stopLogStream`, and `emitLogLine` to `DeviceService` (`package:flutter_tools_extension`). - Implements `startLogStream` and `stopLogStream` on `ExtensionDeviceClient`, introduces `ExtensionDeviceLogReader`, and updates `ExtensionBackedDevice.getLogReader` to cache and dispose a per-device log reader. - Updates `LogsCommand.runCommand()` to skip `applicationPackages.getPackageForPlatform` when `targetPlatform == TargetPlatform.unsupported` (such as custom-platform extension devices). - Adds hermetic unit and isolate RPC tests in `test/general.shard/extension_protocol/extension_device_test.dart` and an end-to-end `LogsCommand` integration test in `test/commands.shard/hermetic/tool_extensions_device_test.dart`. Part of flutter#190755 Part of flutter#190750 ## Pre-launch Checklist - [x] I read the [Contributor Guide] and followed the process outlined there for submitting PRs. - [x] I read the [Tree Hygiene] wiki page, which explains my responsibilities. - [x] I read and followed the [Flutter Style Guide], including [Features we expect every widget to implement]. - [x] I signed the [CLA]. - [x] I listed at least one issue that this PR fixes in the description above. - [x] I updated/added relevant documentation (doc comments with `///`). - [x] I added new tests to check the change I am making, or this PR is [test-exempt]. - [x] I followed the [breaking change policy] and added [Data Driven Fixes] where supported. - [x] All existing and new tests are passing.

…5389) Updates `DeviceLogReader.dispose` to return `Future<void>` and awaits disposal across device log reader implementations and callers. Follow-up to flutter#194964 (comment) Part of flutter#190755

bkonyi added 2 commits October 21, 2026 15:58

bkonyi added the CICD Run CI/CD label Oct 21, 2026

github-actions Bot added the tool Affects the "flutter" command-line tool. See also t: labels. label Oct 21, 2026

bkonyi added 3 commits October 21, 2026 21:04

Merge branch 'ft-ext-protocol-notifications-cancellation' into ft-ext…

b0ea3bd

…-device-log-streaming # Conflicts: # packages/flutter_tools/packages/flutter_tools_extension/lib/src/protocol_base/provider.dart

bkonyi mentioned this pull request Oct 21, 2026

[flutter_tools] Add JSON-RPC notification support and post-handshake isolate exit handling to ExtensionConnection #194961

Merged

bkonyi added 6 commits October 21, 2026 21:24

Merge branch 'ft-ext-protocol-notifications-cancellation' into ft-ext…

6e487fa

…-device-log-streaming

Merge branch 'ft-ext-protocol-notifications-cancellation' into ft-ext…

d30d367

…-device-log-streaming

Merge branch 'ft-ext-protocol-notifications-cancellation' into ft-ext…

26b99e6

…-device-log-streaming

bkonyi added 2 commits October 23, 2026 16:51

Merge remote-tracking branch 'origin/master' into ft-ext-device-log-s…

3d85aea

…treaming # Conflicts: # packages/flutter_tools/packages/flutter_tools_extension/lib/src/device.dart

bkonyi marked this pull request as ready for review October 23, 2026 19:31

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bkonyi requested review from chingjun and loic-sharma October 23, 2026 19:37

loic-sharma reviewed Oct 24, 2026

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Comment thread packages/flutter_tools/lib/src/experimental/extension_device_manager.dart Resolved

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Comment thread packages/flutter_tools/lib/src/experimental/extension_device_manager.dart Resolved

bkonyi added 3 commits October 25, 2026 22:24

[flutter_tools] Cache ExtensionBackedDevice instances across polls in…

5046642

… ExtensionDevices

[flutter_tools] Schedule pending log flush in microtask for multiple …

d2f4708

…broadcast subscribers

[flutter_tools] Document microtask deferral for ExtensionDeviceLogRea…

2c62460

…der initial buffer flush

flutter-dashboard Bot added the will affect goldens Changes to golden files label Oct 26, 2026

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bkonyi mentioned this pull request Oct 27, 2026

[flutter_tools] Make DeviceLogReader.dispose asynchronous #195389

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Merged via the queue into flutter:master with commit 4e9c63a Oct 27, 2026
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[flutter_tools] Add device log streaming support to DeviceService and ExtensionBackedDevice - #194964

[flutter_tools] Add device log streaming support to DeviceService and ExtensionBackedDevice#194964
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