fix(datastore): change OutgoingMutationQueue use TaskQueue for state transitions #3720
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| @@ -55,7 +52,7 @@ final class OutgoingMutationQueue: OutgoingMutationQueueBehavior { | |||
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| let operationQueue = OperationQueue() | |||
| operationQueue.name = "com.amazonaws.OutgoingMutationOperationQueue" | |||
| operationQueue.underlyingQueue = mutationDispatchQueue | |||
| operationQueue.qualityOfService = .default | |||
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i think the default is .default so no need to set this
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According to the doc, the default value for the OperationQueue is NSOperationQualityOfServiceBackground. I set it to the .default because DispatchQueue.global() uses a default quality of service (qos = .default).
For queues you create yourself, the default value is NSOperationQualityOfServiceBackground. For the queue returned by the main method, the default value is NSOperationQualityOfServiceUserInteractive and cannot be changed.
...urces/AWSDataStorePlugin/Sync/MutationSync/OutgoingMutationQueue/OutgoingMutationQueue.swift
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…ionSync/OutgoingMutationQueue/OutgoingMutationQueue.swift Co-authored-by: Michael Law <[email protected]>
Codecov ReportAttention: Patch coverage is
Additional details and impacted files@@ Coverage Diff @@
## main #3720 +/- ##
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+ Coverage 68.38% 68.46% +0.07%
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Files 1089 1089
Lines 37651 37651
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+ Hits 25748 25777 +29
+ Misses 11903 11874 -29
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Issue #
The crash reports indicate that a
SEGV_ACCERRoccurred due to an attempted dereference of a garbage pointer. In the implementation of theOutgoingMutationQueue, themutationDispatchQueuewas targeted to the concurrent global queue, with state transition actions being dispatched to this queue. This setup means thatstartingandstoppingcould trigger two state transite operations running concurrently. Specifically, the starting action needs to complete some I/O work, while the stopping action is cleaning up the operation queue, potentially causing a data race.Description
In this PR, we modified
mutationDispatchQueueto use theTaskQueueimplementation, ensuring that all state transition actions run serially. Also, we set the mutation eventoperationQueueto have the same QOS as the global queue and removed the underlying queue.General Checklist
Given When Theninline code documentation and are named accordinglytestThing_condition_expectation()By submitting this pull request, I confirm that my contribution is made under the terms of the Apache 2.0 license.