Avoid reentrancy issues when dropping AppHost, even harder#19395
Merged
Avoid reentrancy issues when dropping AppHost, even harder#19395
Conversation
The previous fix in #19296 moved the _destruction_ of AppHost into the tail end after we manipulate the `_windows` vector; however, it kept the part which calls into XAML (`Close`) before the `erase`. I suspect that we still had some reentrancy issues, where we cached an iterator before the list was modified by another window close event. That is: ```mermaid sequenceDiagram Emperor->>Emperor: Close Window Emperor->>+AppHost: Close (a) AppHost->>XAML: Close XAML-->>Emperor: pump loop Emperor->>Emperor: Close Window Emperor->>+AppHost: Close (b) AppHost->>XAML: Close XAML-->>Emperor: pump loop AppHost->>-Emperor: Closed Emperor->>Emperor: erase(b) AppHost->>-Emperor: Closed Emperor->>Emperor: erase(a) ``` Moving the `Close()` to after the `erase` ensures that there are no cached iterators that survive beyond XAML pumping the message loop. Fixes 8d41ace
carlos-zamora
approved these changes
Sep 29, 2025
DHowett
added a commit
that referenced
this pull request
Oct 8, 2025
The previous fix in #19296 moved the _destruction_ of AppHost into the tail end after we manipulate the `_windows` vector; however, it kept the part which calls into XAML (`Close`) before the `erase`. I suspect that we still had some reentrancy issues, where we cached an iterator before the list was modified by another window close event. That is: ```mermaid sequenceDiagram Emperor->>Emperor: Close Window Emperor->>+AppHost: Close (a) AppHost->>XAML: Close XAML-->>Emperor: pump loop Emperor->>Emperor: Close Window Emperor->>+AppHost: Close (b) AppHost->>XAML: Close XAML-->>Emperor: pump loop AppHost->>-Emperor: Closed Emperor->>Emperor: erase(b) AppHost->>-Emperor: Closed Emperor->>Emperor: erase(a) ``` Moving the `Close()` to after the `erase` ensures that there are no cached iterators that survive beyond XAML pumping the message loop. Fixes 8d41ace (cherry picked from commit 5976de1) Service-Card-Id: PVTI_lADOAF3p4s4AxadtzgfScoo Service-Version: 1.23
DHowett
added a commit
that referenced
this pull request
Oct 8, 2025
The previous fix in #19296 moved the _destruction_ of AppHost into the tail end after we manipulate the `_windows` vector; however, it kept the part which calls into XAML (`Close`) before the `erase`. I suspect that we still had some reentrancy issues, where we cached an iterator before the list was modified by another window close event. That is: ```mermaid sequenceDiagram Emperor->>Emperor: Close Window Emperor->>+AppHost: Close (a) AppHost->>XAML: Close XAML-->>Emperor: pump loop Emperor->>Emperor: Close Window Emperor->>+AppHost: Close (b) AppHost->>XAML: Close XAML-->>Emperor: pump loop AppHost->>-Emperor: Closed Emperor->>Emperor: erase(b) AppHost->>-Emperor: Closed Emperor->>Emperor: erase(a) ``` Moving the `Close()` to after the `erase` ensures that there are no cached iterators that survive beyond XAML pumping the message loop. Fixes 8d41ace (cherry picked from commit 5976de1) Service-Card-Id: PVTI_lADOAF3p4s4BBcTlzgfScpM Service-Version: 1.24
This was referenced Jan 12, 2026
Closed
This file contains hidden or bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment
3 participants
Add this suggestion to a batch that can be applied as a single commit.This suggestion is invalid because no changes were made to the code.Suggestions cannot be applied while the pull request is closed.Suggestions cannot be applied while viewing a subset of changes.Only one suggestion per line can be applied in a batch.Add this suggestion to a batch that can be applied as a single commit.Applying suggestions on deleted lines is not supported.You must change the existing code in this line in order to create a valid suggestion.Outdated suggestions cannot be applied.This suggestion has been applied or marked resolved.Suggestions cannot be applied from pending reviews.Suggestions cannot be applied on multi-line comments.Suggestions cannot be applied while the pull request is queued to merge.Suggestion cannot be applied right now. Please check back later.
The previous fix in #19296 moved the destruction of AppHost into the tail end after we manipulate the
_windowsvector; however, it kept the part which calls into XAML (Close) before theerase. I suspect that we still had some reentrancy issues, where we cached an iterator before the list was modified by another window close event.That is:
Moving the
Close()to after theeraseensures that there are no cached iterators that survive beyond XAML pumping the message loop.Fixes 8d41ace