fix: thread-safe signal emission in FileProviderService XPC callback#9349
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i2h3 merged 3 commits intoi2h3/fix/9682755-excluded-sync-statusfrom Jan 21, 2026
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Use QMetaObject::invokeMethod with Qt::QueuedConnection to emit the syncStateChanged signal from the Objective-C callback that may be called on an XPC dispatch queue (non-main thread). This ensures the signal is emitted on the correct thread where the FileProviderService object lives, preventing potential thread safety issues. Co-authored-by: i2h3 <142165879+i2h3@users.noreply.github.com>
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[WIP] Fix File Provider Synchronization Status based on review feedback
fix: thread-safe signal emission in FileProviderService XPC callback
Jan 21, 2026
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@copilot Resolve the conflicts! |
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January 21, 2026 10:29
…-pr-9335-again Signed-off-by: Iva Horn <iva.horn@nextcloud.com>
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Jan 21, 2026
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i2h3/fix/9682755-excluded-sync-status
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Pull request overview
This pull request addresses a thread-safety issue in the FileProviderService XPC communication layer by ensuring signals are emitted on the correct thread. The syncStateChanged signal was previously emitted directly from an Objective-C XPC callback executing on a dispatch queue, which violated Qt's thread-safety requirements for signal emission.
Changes:
- Replace direct signal emission with
QMetaObject::invokeMethodusingQt::QueuedConnectionto queue signal emission to the FileProviderService object's thread - Add
QMetaObjectheader include for the invokeMethod API - Add explanatory comment documenting the thread-safety rationale
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Addresses feedback from #9335 regarding thread safety in the FileProviderService XPC communication layer.
Description
The
syncStateChangedsignal was emitted directly from an Objective-C XPC callback that executes on a dispatch queue, not the main thread. Qt signals require emission on the object's thread to maintain signal/slot connection guarantees.Changes
QMetaObject::invokeMethodwithQt::QueuedConnectionto queue signal emission to the FileProviderService object's threadThis follows established Qt patterns for cross-thread signal emission and matches usage elsewhere in the codebase.
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