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Fix race condition in generic diagnostic listener #948
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Please ignore build failure, it was cancelled, re-started and passed, but github did not pick up successful run |
| private List<IDisposable> individualSubscriptions; | ||
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| protected DiagnosticSourceListenerBase(TelemetryConfiguration configuration) | ||
| { | ||
| this.Configuration = configuration; | ||
| this.Client = new TelemetryClient(configuration); | ||
| } | ||
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| public void Subscribe() |
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for this public method, can you please add a
describing What this is, Why this is?
cijothomas
approved these changes
Jul 9, 2018
| @@ -16,13 +16,25 @@ internal abstract class DiagnosticSourceListenerBase<TContext> : IObserver<Diagn | |||
| protected readonly TelemetryClient Client; | |||
| protected readonly TelemetryConfiguration Configuration; | |||
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| private readonly IDisposable listenerSubscription; | |||
| private IDisposable listenerSubscription; | |||
| private List<IDisposable> individualSubscriptions; | |||
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| protected DiagnosticSourceListenerBase(TelemetryConfiguration configuration) | |||
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Because the Subscribe method is required, should we make a reference to it in the constructor?
I don't know how often a developer creates a new DiagnosticSourceListener (probably not often :) ), but I wonder that they may not know to look for the Subscribe method.
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this is an internal class, it's only us who call this method and just once. I can add the comment, though
TimothyMothra
approved these changes
Jul 10, 2018
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When generic diagnostic listener subscribes to DiagnosticSource, it attempts to use this in its own constructor, while some properties (filters) are not initialized yet.
As a result, if DiagnosticSource is created BEFORE the generic listener, it's guaranteed to miss subscription event and never receive anything.
This PR fixes this issue.
For significant contributions please make sure you have completed the following items:
Changes in public surface reviewed
Design discussion issue #
CHANGELOG.md updated with one line description of the fix, and a link to the original issue.
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