Saves a DeviceHolderVK with the CommandPoolVK by gaaclarke · Pull Request #186749 · flutter/flutter

gaaclarke · 2026-05-19T15:59:32Z

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Code Review

This pull request updates CommandPoolVK to use DeviceHolderVK for tracking the Vulkan device lifecycle, ensuring resources are released without calling destruction functions if the device is already destroyed. Changes include updates to the destructor, the Destroy method, and the addition of a unit test. Feedback identifies that the Destroy method should also release command buffers when the device is invalid and suggests enhancing the unit test to verify that command buffers are not freed in such scenarios.

gemini-code-assist · 2026-05-19T16:02:00Z

+TEST(CommandPoolVKTest, DestroysCleanlyIfDeviceIsDestroyed) {
+  auto const context = MockVulkanContextBuilder().Build();
+
+  // Create a vk::UniqueCommandPool
+  vk::CommandPoolCreateInfo info;
+  info.setQueueFamilyIndex(context->GetGraphicsQueue()->GetIndex().family);
+  info.setFlags(vk::CommandPoolCreateFlagBits::eTransient);
+
+  auto device = context->GetDevice();
+  auto [result, pool] = device.createCommandPoolUnique(info);
+  ASSERT_EQ(result, vk::Result::eSuccess);
+
+  auto device_holder = std::make_shared<MockDeviceHolder>(device);
+  std::weak_ptr<DeviceHolderVK> weak_device_holder = device_holder;
+
+  auto command_pool = std::make_unique<CommandPoolVK>(
+      std::move(pool), std::vector<vk::UniqueCommandBuffer>{}, context,
+      weak_device_holder);
+
+  // Now, destroy the device holder.
+  device_holder.reset();
+
+  // Now, destroy the command pool. Since the device holder is dead, this should
+  // NOT call vkDestroyCommandPool.
+  command_pool.reset();
+
+  auto const called = ReclaimAndGetMockVulkanFunctions(context);
+  EXPECT_EQ(std::count(called->begin(), called->end(), "vkDestroyCommandPool"),
+            0u);
+
+  context->Shutdown();
+}


The test currently only verifies that vkDestroyCommandPool is not called. It would be more robust to also verify that vkFreeCommandBuffers is not called, especially since the CommandPoolVK holds vectors of command buffers that must also be released when the device is gone. Consider adding some mock command buffers to the pool in this test case to ensure they are handled correctly.

jason-simmons

Have you been able to reproduce something like what was described in #186458?

The stack trace there mentioned BackgroundCommandPoolVK. There may be some similar potential races involving interactions between BackgroundCommandPoolVK and destruction of the ContextVK. But I haven't reproduced it locally and have not identified the sequence of events that would cause the trace in #186458.

In any case, this is a good improvement. The CommandPoolVK ownership model is complicated, and there could be situations where a CommandPoolVK is destructed after the ContextVK and the Vulkan device have been deleted.

gaaclarke · 2026-05-21T16:23:28Z

Have you been able to reproduce something like what was described in #186458?

No, this change is based on the patch the OP posted that they claim removes their crash. In their patch they maintained a shared_ptr to the holder, which is wrong. This follows the same pattern we use for other vulkan object cleanup.

jason-simmons

LGTM

Can you change the PR comment from "fixes #186458" to "see #186458"?

I'd like to keep #186458 open in case anyone has more information about issues involving BackgroundCommandPoolVK.

gaaclarke · 2026-05-21T17:17:26Z

Can you change the PR comment from "fixes #186458" to "see #186458"?

sure, done

auto-submit · 2026-05-21T17:31:27Z

autosubmit label was removed for flutter/flutter/186749, because - The status or check suite Mac customer_testing has failed. Please fix the issues identified (or deflake) before re-applying this label.

auto-submit · 2026-05-21T18:02:14Z

autosubmit label was removed for flutter/flutter/186749, because - The status or check suite Linux linux_fuchsia_tests has failed. Please fix the issues identified (or deflake) before re-applying this label.

auto-submit · 2026-05-21T18:29:16Z

autosubmit label was removed for flutter/flutter/186749, because - The status or check suite Linux linux_fuchsia_tests has failed. Please fix the issues identified (or deflake) before re-applying this label.

fluttergithubbot · 2026-05-21T20:40:21Z

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auto-submit · 2026-05-21T22:30:13Z

autosubmit label was removed for flutter/flutter/186749, because - The status or check suite Linux linux_fuchsia_tests has failed. Please fix the issues identified (or deflake) before re-applying this label.

gaaclarke · 2026-05-21T22:48:09Z

This keeps getting stuck on fuchsia failures. They don't sound apropos I'll try rerunning one last time.

[stderr - main]
embedder.cc (2041): 'FlutterEngineInitialize' returned 'kInvalidArguments'. The assets path in the Flutter project arguments was missing.
embedder.cc (3030): 'FlutterEngineSendPlatformMessage' returned 'kInvalidArguments'. Message size was non-zero but the message data was nullptr.
embedder.cc (2500): 'FlutterEngineRunInitialized' returned 'kInvalidArguments'. Engine handle was invalid.
embedder.cc (2500): 'FlutterEngineRunInitialized' returned 'kInvalidArguments'. Engine handle was invalid.
embedder.cc (2709): 'FlutterEngineSendWindowMetricsEvent' returned 'kInvalidArguments'. Viewport metrics were invalid.
embedder.cc (2603): 'FlutterEngineRemoveView' returned 'kInvalidArguments'. Remove view info was invalid. The implicit view cannot be removed.
embedder.cc (3426): 'FlutterEngineUpdateLocales' returned 'kInvalidArguments'. Language code is required but not present in FlutterLocale.
embedder.cc (2500): 'FlutterEngineRunInitialized' returned 'kInvalidArguments'. Engine handle was invalid.
embedder.cc (2700): 'FlutterEngineSendWindowMetricsEvent' returned 'kInvalidArguments'. Device pixel ratio was invalid. It must be greater than zero.
embedder.cc (2700): 'FlutterEngineSendWindowMetricsEvent' returned 'kInvalidArguments'. Physical view insets are invalid. They must be non-negative.
embedder.cc (2700): 'FlutterEngineSendWindowMetricsEvent' returned 'kInvalidArguments'. Physical view insets are invalid. They cannot be greater than physical height or width.
embedder.cc (2700): 'FlutterEngineSendWindowMetricsEvent' returned 'kInvalidArguments'. Window metrics are invalid. Width and height must be within the specified constraints.
embedder.cc (2700): 'FlutterEngineSendWindowMetricsEvent' returned 'kInvalidArguments'. Window metrics are invalid. Width and height must be within the specified constraints.
embedder.cc (2700): 'FlutterEngineSendWindowMetricsEvent' returned 'kInvalidArguments'. Window metrics are invalid. Width and height must be within the specified constraints.
[FAILED]	main

Failed tests: main
0 out of 1 tests passed...
fuchsia-pkg://fuchsia.com/embedder_tests#meta/embedder_tests.cm completed with result: FAILED
Tests failed.

Roll Flutter from e03b91f1fe34 to f3a4b9897834 (63 revisions) flutter/flutter@e03b91f...f3a4b98 2026-05-26 47866232+chunhtai@users.noreply.github.com Update batch release doc to reflect latest workflow (flutter/flutter#186979) 2026-05-26 engine-flutter-autoroll@skia.org Roll Skia from 0442274cc696 to 27a819894f7c (5 revisions) (flutter/flutter#187094) 2026-05-26 bkonyi@google.com [Tool Robustness] Gracefully handle asynchronous subprocess crashes and connection timeouts (flutter/flutter#186964) 2026-05-26 bkonyi@google.com [pubspec] Bump Dart SDK constraint to ^3.13.0 (flutter/flutter#186957) 2026-05-26 engine-flutter-autoroll@skia.org Roll Dart SDK from 7eb54169841d to 00e625453c43 (1 revision) (flutter/flutter#187086) 2026-05-26 bdero@google.com [Impeller] Retire Y-coord-scale plumbing by flipping GLES at the vertex stage (flutter/flutter#186556) 2026-05-26 engine-flutter-autoroll@skia.org Roll Skia from f4f294bdf98d to 0442274cc696 (2 revisions) (flutter/flutter#187079) 2026-05-26 kevmoo@users.noreply.github.com [flutter_tools] Fix version cache poisoning from git environment variables (flutter/flutter#186595) 2026-05-26 bkonyi@google.com [Tool] Handle DTD connection failures gracefully in widget-preview (flutter/flutter#186952) 2026-05-25 engine-flutter-autoroll@skia.org Roll Skia from 9d1adb5f2427 to f4f294bdf98d (1 revision) (flutter/flutter#187056) 2026-05-25 engine-flutter-autoroll@skia.org Roll Skia from 4dd78179e6ec to 9d1adb5f2427 (1 revision) (flutter/flutter#187048) 2026-05-25 engine-flutter-autoroll@skia.org Roll Skia from 1f26101197bf to 4dd78179e6ec (4 revisions) (flutter/flutter#187044) 2026-05-24 engine-flutter-autoroll@skia.org Roll Skia from bbe9ccc2bdbf to 1f26101197bf (1 revision) (flutter/flutter#187016) 2026-05-24 engine-flutter-autoroll@skia.org Roll Fuchsia Linux SDK from nsgcNDlZOuweOvy3Q... to Itd2Jq_ZIABH2rW7B... (flutter/flutter#187032) 2026-05-23 engine-flutter-autoroll@skia.org Roll Dart SDK from 7e0f28eb5315 to 7eb54169841d (1 revision) (flutter/flutter#187005) 2026-05-23 engine-flutter-autoroll@skia.org Roll Dart SDK from 90e55fa88456 to 7e0f28eb5315 (1 revision) (flutter/flutter#186990) 2026-05-23 engine-flutter-autoroll@skia.org Roll Fuchsia Linux SDK from 6T6BY9PTftoG3vP_1... to nsgcNDlZOuweOvy3Q... (flutter/flutter#186984) 2026-05-23 chris@bracken.jp iOS] Migrate VSyncClient to a pure Obj-C implementation (#186166) (flutter/flutter#186935) 2026-05-23 30870216+gaaclarke@users.noreply.github.com Disables embedder_tests.cm for fuchsia (flutter/flutter#186969) 2026-05-23 engine-flutter-autoroll@skia.org Roll Dart SDK from b8414c46f6c7 to 90e55fa88456 (2 revisions) (flutter/flutter#186977) 2026-05-22 engine-flutter-autoroll@skia.org Roll Skia from 6fdb013d1953 to bbe9ccc2bdbf (1 revision) (flutter/flutter#186980) 2026-05-22 mdebbar@google.com [web] Fix cutoff text in WebParagraph (flutter/flutter#186819) 2026-05-22 1961493+harryterkelsen@users.noreply.github.com fix(web): Removes the iterative downscaling hack (flutter/flutter#186914) 2026-05-22 30870216+gaaclarke@users.noreply.github.com opts the linux embedder into sdf rendering (flutter/flutter#186909) 2026-05-22 engine-flutter-autoroll@skia.org Roll Skia from dae8778ca40d to 6fdb013d1953 (5 revisions) (flutter/flutter#186970) 2026-05-22 dacoharkes@google.com Fix hooks inputs outputs rebuilt (flutter/flutter#186701) 2026-05-22 30870216+gaaclarke@users.noreply.github.com adds linux impeller integration test for external textures (flutter/flutter#186759) 2026-05-22 kevmoo@users.noreply.github.com fix(flutter_tools): defensively catch DWDS unregistered service extension errors (flutter/flutter#186896) 2026-05-22 bdero@google.com [Impeller] Add golden harness support to the renderer test layer (flutter/flutter#186735) 2026-05-22 mdebbar@google.com [web] Remove image codecs from canvaskit_chromium (flutter/flutter#178133) 2026-05-22 30870216+gaaclarke@users.noreply.github.com opts all macos into wide gamut (flutter/flutter#186277) 2026-05-22 engine-flutter-autoroll@skia.org Roll Skia from 356185490a75 to dae8778ca40d (9 revisions) (flutter/flutter#186949) 2026-05-22 1598289+lukemmtt@users.noreply.github.com Filter out SwiftPM schemes when fetching schemes (flutter/flutter#186006) 2026-05-22 engine-flutter-autoroll@skia.org Roll Packages from 3754d04 to 69cf959 (1 revision) (flutter/flutter#186950) 2026-05-22 engine-flutter-autoroll@skia.org Roll Dart SDK from eca46bec956d to b8414c46f6c7 (2 revisions) (flutter/flutter#186944) 2026-05-22 30870216+gaaclarke@users.noreply.github.com Saves a DeviceHolderVK with the CommandPoolVK (flutter/flutter#186749) 2026-05-22 engine-flutter-autoroll@skia.org Roll Dart SDK from e0d509fd676e to eca46bec956d (1 revision) (flutter/flutter#186922) 2026-05-22 bkonyi@google.com [ Tool ] Stop generating widget preview scaffold under $TMP (flutter/flutter#186476) 2026-05-21 737941+loic-sharma@users.noreply.github.com Fix typo in StretchingOverscrollIndicator docs (flutter/flutter#186897) 2026-05-21 engine-flutter-autoroll@skia.org Roll Dart SDK from 28c7cb5a8e8d to e0d509fd676e (1 revision) (flutter/flutter#186903) 2026-05-21 jason-simmons@users.noreply.github.com Fix some issues in the integration between EmbedderExternalViewEmbedder and Impeller (flutter/flutter#184905) 2026-05-21 jason-simmons@users.noreply.github.com Fix a potential buffer overflow in the animated PNG decoder when parsing malformed fdAT chunks (flutter/flutter#186700) 2026-05-21 engine-flutter-autoroll@skia.org Roll Skia from 2ff20950975d to 356185490a75 (5 revisions) (flutter/flutter#186892) 2026-05-21 flar@google.com Add primitive shadows to rendering benchmark (flutter/flutter#186779) 2026-05-21 15619084+vashworth@users.noreply.github.com Move prefetchSwiftPackages to be per platform (flutter/flutter#186468) 2026-05-21 okorohelijah@google.com Upgrade iOS version (flutter/flutter#186889) ...

Started saving a deviceholder with the command pool

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Comment thread engine/src/flutter/impeller/renderer/backend/vulkan/command_pool_vk.cc

Comment thread engine/src/flutter/impeller/renderer/backend/vulkan/command_pool_vk.cc Outdated

jason feedback

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Merge branch 'master' into weak-ptr-command-pool

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[Impeller][Vulkan] CommandPoolVK can free command buffers on a destroyed VkDevice, crashing in vkFreeCommandBuffers on the resource manager thread #186458

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