Fix the issue on macOS where, after a hot restart with multiple windows, unresponsive windows are left behind. by yiiim · Pull Request #180287 · flutter/flutter

yiiim · 2025-12-25T14:43:29Z

There is currently an issue with multiple windows on macOS: after a hot restart, new windows are created, but the original windows are not closed. You can reproduce this by running examples/multiple_windows and then performing a hot restart.

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.

If you need help, consider asking for advice on the #hackers-new channel on Discord.

Note: The Flutter team is currently trialing the use of Gemini Code Assist for GitHub. Comments from the gemini-code-assist bot should not be taken as authoritative feedback from the Flutter team. If you find its comments useful you can update your code accordingly, but if you are unsure or disagree with the feedback, please feel free to wait for a Flutter team member's review for guidance on which automated comments should be addressed.

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Code Review

This pull request addresses an issue on macOS where windows were not being closed after a hot restart in multi-window mode. The fix involves calling closeAllWindows on the FlutterWindowController during the onPreEngineRestart engine callback. The closeAllWindows method has been moved from a testing-only category to the main interface to allow this. A new test case has been added to verify that multiple windows are correctly closed. The changes look correct and effectively solve the described problem.

gemini-code-assist · 2025-12-25T14:45:31Z

engine/src/flutter/shell/platform/darwin/macos/framework/Source/FlutterWindowControllerTest.mm

+  int64_t handle1 = InternalFlutter_WindowController_CreateRegularWindow(engine_id, &request);
+  int64_t handle2 = InternalFlutter_WindowController_CreateRegularWindow(engine_id, &request);
+  int64_t handle3 = InternalFlutter_WindowController_CreateRegularWindow(engine_id, &request);
+
+  // Verify windows are created
+  FlutterViewController* viewController1 = [engine viewControllerForIdentifier:handle1];
+  FlutterViewController* viewController2 = [engine viewControllerForIdentifier:handle2];
+  FlutterViewController* viewController3 = [engine viewControllerForIdentifier:handle3];
+  EXPECT_NE(viewController1, nil);
+  EXPECT_NE(viewController2, nil);
+  EXPECT_NE(viewController3, nil);
+
+  // Close all windows
+  [engine.windowController closeAllWindows];
+
+  // Verify all windows are closed and view controllers are disposed
+  viewController1 = [engine viewControllerForIdentifier:handle1];
+  viewController2 = [engine viewControllerForIdentifier:handle2];
+  viewController3 = [engine viewControllerForIdentifier:handle3];
+  EXPECT_EQ(viewController1, nil);
+  EXPECT_EQ(viewController2, nil);
+  EXPECT_EQ(viewController3, nil);


To improve the test's readability and maintainability, you could refactor it to use a loop for creating and verifying the windows. This avoids repetition and makes it easier to adjust the number of windows being tested.

const int kWindowCount = 3; int64_t handles[kWindowCount]; for (int i = 0; i < kWindowCount; ++i) { handles[i] = InternalFlutter_WindowController_CreateRegularWindow(engine_id, &request); } // Verify windows are created for (int i = 0; i < kWindowCount; ++i) { EXPECT_NE([engine viewControllerForIdentifier:handles[i]], nil); } // Close all windows [engine.windowController closeAllWindows]; // Verify all windows are closed and view controllers are disposed for (int i = 0; i < kWindowCount; ++i) { EXPECT_EQ([engine viewControllerForIdentifier:handles[i]], nil); }

hellohuanlin · 2026-01-15T22:35:52Z

@knopp from triage: do you plan to review this? thanks

knopp

LGTM, except the question for the test.

engine/src/flutter/shell/platform/darwin/macos/framework/Source/FlutterWindowControllerTest.mm

knopp

LGTM! Thanks.

auto-submit · 2026-01-22T14:03:45Z

autosubmit label was removed for flutter/flutter/180287, because This PR has not met approval requirements for merging. Changes were requested by {knopp}, please make the needed changes and resubmit this PR.
The PR author is a member of flutter-hackers and needs 2 more review(s) in order to merge this PR.

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…iple windows, unresponsive windows are left behind. (flutter/flutter#180287)

Roll Flutter from dfd92b773219 to da72d5936d69 (39 revisions) flutter/flutter@dfd92b7...da72d59 2026-01-29 98614782+auto-submit[bot]@users.noreply.github.com Reverts "[ Tool / Engine ] Cleanup x86 references (#181152)" (flutter/flutter#181643) 2026-01-29 [email protected] Roll Skia from 174db42b7300 to 89df65f8324c (2 revisions) (flutter/flutter#181636) 2026-01-29 [email protected] [material/menu_anchor.dart] Add animations to MenuAnchor. (flutter/flutter#176494) 2026-01-28 [email protected] Roll Skia from 8e09f8a82251 to 174db42b7300 (6 revisions) (flutter/flutter#181627) 2026-01-28 [email protected] Send statusBarTouch events via dedicated messages (flutter/flutter#179643) 2026-01-28 [email protected] test: Improve DropdownMenuFormField tests (flutter/flutter#181369) 2026-01-28 [email protected] Account for vec3 padding in Metal (flutter/flutter#181563) 2026-01-28 [email protected] [ Tool / Engine ] Cleanup x86 references (flutter/flutter#181152) 2026-01-28 [email protected] Fix the issue on macOS where, after a hot restart with multiple windows, unresponsive windows are left behind. (flutter/flutter#180287) 2026-01-28 [email protected] Roll Skia from 675444e94bc9 to 8e09f8a82251 (7 revisions) (flutter/flutter#181606) 2026-01-28 [email protected] Roll Packages from e37af11 to 1cb2148 (5 revisions) (flutter/flutter#181608) 2026-01-28 [email protected] fix: swap app and engine version in vk::ApplicationInfo (flutter/flutter#181432) 2026-01-28 [email protected] Adds impeller backend to skia gold client (flutter/flutter#181503) 2026-01-28 [email protected] Remove chrome_and_driver dependency where it's not needed (flutter/flutter#178174) 2026-01-28 [email protected] chore: Windows_mokey basic_material_app_win__compile !bringup (flutter/flutter#180985) 2026-01-28 [email protected] Fix generating both `settings.gradle` and `settings.gradle.kts` for plugins (flutter/flutter#181592) 2026-01-28 [email protected] Roll Skia from 6614f89de521 to 675444e94bc9 (3 revisions) (flutter/flutter#181587) 2026-01-28 [email protected] Fix `todayBorder` todayBorder color is incorrectly overridden by `todayForegroundColor` in CalendarDatePicker (flutter/flutter#178792) 2026-01-28 [email protected] Roll Skia from 8f1695a4b328 to 6614f89de521 (2 revisions) (flutter/flutter#181583) 2026-01-28 [email protected] feat: add RoundedSuperellipseInputBorder (flutter/flutter#177220) 2026-01-28 [email protected] Roll Dart SDK from 38e351498549 to f10dcbfca98f (2 revisions) (flutter/flutter#181582) 2026-01-28 [email protected] Roll Skia from f424d58e37a3 to 8f1695a4b328 (6 revisions) (flutter/flutter#181577) 2026-01-28 [email protected] Remove unused code paths in `PlatformViewsController.java` (flutter/flutter#181393) 2026-01-28 [email protected] feat: add onEnd to AnimatedCrossFade (flutter/flutter#181455) 2026-01-28 [email protected] Don't pass bounds to saveLayer call when painting ImageFilter (flutter/flutter#181353) 2026-01-28 [email protected] test: Clarify failure messages on gestures/debug_test.dart (flutter/flutter#181109) 2026-01-27 [email protected] Roll Fuchsia Linux SDK from akraNGn2lw4T1msgZ... to adhoq9ouVRh0xzkm3... (flutter/flutter#181571) 2026-01-27 [email protected] Roll Dart SDK from 4c7cb0a1d07d to 38e351498549 (4 revisions) (flutter/flutter#181570) 2026-01-27 [email protected] Make sure that an AnimatedPadding doesn't crash in 0x0 environment (flutter/flutter#181235) 2026-01-27 [email protected] Make sure that an ImageFiltered doesn't crash at 0x0 environment (flutter/flutter#181067) 2026-01-27 [email protected] Marks firebase_release_smoke_test to be unflaky (flutter/flutter#181308) 2026-01-27 [email protected] Fix remove material import box decoration test (flutter/flutter#181253) 2026-01-27 [email protected] Roll Skia from c2754838b077 to f424d58e37a3 (8 revisions) (flutter/flutter#181564) 2026-01-27 [email protected] Make sure that an AnimatedAlign doesn't crash in 0x0 environment (flutter/flutter#181361) 2026-01-27 [email protected] Make sure that an ImageIcon doesn't crash in 0x0 environment (flutter/flutter#181099) 2026-01-27 [email protected] Make sure that an AnimatedContainer doesn't crash in 0x0 environment (flutter/flutter#181198) 2026-01-27 [email protected] Make sure that an AnimatedRotation doesn't crash in 0x0 environment (flutter/flutter#181486) 2026-01-27 [email protected] Make sure that an AnimatedPositionedDirectional doesn't crash in 0x0 … (flutter/flutter#181451) 2026-01-27 [email protected] Merge changelog for 3.38.8. (flutter/flutter#181558) If this roll has caused a breakage, revert this CL and stop the roller 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. ...

…ws, unresponsive windows are left behind. (flutter#180287) There is currently an issue with multiple windows on macOS: after a hot restart, new windows are created, but the original windows are not closed. You can reproduce this by running examples/multiple_windows and then performing a hot restart. ## 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. - [ ] 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. If you need help, consider asking for advice on the #hackers-new channel on [Discord]. **Note**: The Flutter team is currently trialing the use of [Gemini Code Assist for GitHub](https://developers.google.com/gemini-code-assist/docs/review-github-code). Comments from the `gemini-code-assist` bot should not be taken as authoritative feedback from the Flutter team. If you find its comments useful you can update your code accordingly, but if you are unsure or disagree with the feedback, please feel free to wait for a Flutter team member's review for guidance on which automated comments should be addressed.  [Contributor Guide]: https://github.com/flutter/flutter/blob/main/docs/contributing/Tree-hygiene.md#overview [Tree Hygiene]: https://github.com/flutter/flutter/blob/main/docs/contributing/Tree-hygiene.md [test-exempt]: https://github.com/flutter/flutter/blob/main/docs/contributing/Tree-hygiene.md#tests [Flutter Style Guide]: https://github.com/flutter/flutter/blob/main/docs/contributing/Style-guide-for-Flutter-repo.md [Features we expect every widget to implement]: https://github.com/flutter/flutter/blob/main/docs/contributing/Style-guide-for-Flutter-repo.md#features-we-expect-every-widget-to-implement [CLA]: https://cla.developers.google.com/ [flutter/tests]: https://github.com/flutter/tests [breaking change policy]: https://github.com/flutter/flutter/blob/main/docs/contributing/Tree-hygiene.md#handling-breaking-changes [Discord]: https://github.com/flutter/flutter/blob/main/docs/contributing/Chat.md [Data Driven Fixes]: https://github.com/flutter/flutter/blob/main/docs/contributing/Data-driven-Fixes.md

github-actions bot added engine flutter/engine related. See also e: labels. a: desktop Running on desktop platform-macos labels Dec 25, 2025

gemini-code-assist bot reviewed Dec 25, 2025

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yiiim changed the title ~~After a hot restart in multi-window mode, all windows should be closed.~~ Fix the issue on macOS where, after a hot restart with multiple windows, unresponsive windows are left behind. Dec 25, 2025

yiiim requested a review from knopp December 25, 2025 15:13

knopp requested changes Jan 16, 2026

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engine/src/flutter/shell/platform/darwin/macos/framework/Source/FlutterWindowControllerTest.mm Outdated Show resolved Hide resolved

yiiim force-pushed the multiple_window_macos_fix branch from 1926b90 to c388202 Compare January 19, 2026 10:12

yiiim added 2 commits January 19, 2026 23:38

fix

e0bc322

test

be7a813

yiiim force-pushed the multiple_window_macos_fix branch from c388202 to be7a813 Compare January 19, 2026 15:38

yiiim requested a review from knopp January 20, 2026 01:28

knopp approved these changes Jan 21, 2026

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yiiim added the autosubmit Merge PR when tree becomes green via auto submit App label Jan 22, 2026

knopp added this pull request to the merge queue Jan 28, 2026

Merged via the queue into flutter:master with commit f1a74f4 Jan 28, 2026
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flutter-dashboard bot removed the autosubmit Merge PR when tree becomes green via auto submit App label Jan 28, 2026

engine-flutter-autoroll mentioned this pull request Jan 29, 2026

Roll Flutter from dfd92b773219 to da72d5936d69 (39 revisions) flutter/packages#10923

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engine-flutter-autoroll added a commit to engine-flutter-autoroll/packages that referenced this pull request Jan 29, 2026

f1a74f4e8 Fix the issue on macOS where, after a hot restart with mult…

54b2d83

…iple windows, unresponsive windows are left behind. (flutter/flutter#180287)

Piinks mentioned this pull request Feb 6, 2026

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Fix the issue on macOS where, after a hot restart with multiple windows, unresponsive windows are left behind.#180287

Fix the issue on macOS where, after a hot restart with multiple windows, unresponsive windows are left behind.#180287
knopp merged 2 commits intoflutter:masterfrom
yiiim:multiple_window_macos_fix

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