Unhandled Exception : System.IO.IOException: Sharing violation on path ..../Sentry/xxxxx.envelope

[khalilyamoun]

Environment

Xamarin.Android Sentry-Xamarin : 1.4.3 Sentry-dotnet : 3.23.1

   SentryXamarin.Init(options =>
            {
                options.BeforeBreadcrumb = this.BeforeBreadcrumb;
                options.Dsn = Constants.SentryAndoridDsn;
                options.Environment = Constants.SentryEnvironment;
                options.AddXamarinFormsIntegration();
                options.AttachScreenshots = true;
                options.TracesSampleRate = 0.05;
            });

Steps to Reproduce

1. Open the app
2. Restart the app (Init should be re-called)

Expected Result

App should restart normally.

Actual Result

[mono-rt] [ERROR] FATAL UNHANDLED EXCEPTION: System.IO.IOException: Sharing violation on path /data/user/0/com.package.packagename.dev/files/.local/share/Sentry/2307E3E05F3949AB506007C7897275B7007CF6F7/1667542777_4035__442129975.envelope
[mono-rt]   at System.IO.FileStream..ctor (System.String path, System.IO.FileMode mode, System.IO.FileAccess access, System.IO.FileShare share, System.Int32 bufferSize, System.Boolean anonymous, System.IO.FileOptions options) [0x001aa] in /Users/builder/jenkins/workspace/archive-mono/2020-02/android/release/mcs/class/corlib/System.IO/FileStream.cs:239 
[mono-rt]   at System.IO.FileStream..ctor (System.String path, System.IO.FileMode mode, System.IO.FileAccess access, System.IO.FileShare share, System.Int32 bufferSize, System.IO.FileOptions options) [0x00000] in /Users/builder/jenkins/workspace/archive-mono/2020-02/android/release/mcs/class/corlib/System.IO/FileStream.cs:106 
[mono-rt]   at (wrapper remoting-invoke-with-check) System.IO.FileStream..ctor(string,System.IO.FileMode,System.IO.FileAccess,System.IO.FileShare,int,System.IO.FileOptions)
[mono-rt]   at System.IO.FileSystem.CopyFile (System.String sourceFullPath, System.String destFullPath, System.Boolean overwrite) [0x00025] in /Users/builder/jenkins/workspace/archive-mono/2020-02/android/release/external/corefx/src/System.IO.FileSystem/src/System/IO/FileSystem.Unix.cs:54 
[mono-rt]   at System.IO.File.Copy (System.String sourceFileName, System.String destFileName, System.Boolean overwrite) [0x00056] in /Users/builder/jenkins/workspace/archive-mono/2020-02/android/release/external/corefx/src/System.IO.FileSystem/src/System/IO/File.cs:74 
[mono-rt]   at Sentry.Internal.FileSystem.MoveFile (System.String sourceFileName, System.String destFileName, System.Boolean overwrite) [0x00003] in /_/src/Sentry/Internal/FileSystem.cs:34 
[mono-rt]   at Sentry.Internal.Http.CachingTransport.TryPrepareNextCacheFileAsync (System.Threading.CancellationToken cancellationToken) [0x000c3] in /_/src/Sentry/Internal/Http/CachingTransport.cs:386 
[mono-rt]   at Sentry.Internal.Http.CachingTransport.ProcessCacheAsync (System.Threading.CancellationToken cancellation) [0x000d2] in /_/src/Sentry/Internal/Http/CachingTransport.cs:270 
[mono-rt]   at Sentry.Internal.BackgroundWorker.DoFlushAsync (System.Threading.CancellationToken cancellationToken) [0x001dd] in /_/src/Sentry/Internal/BackgroundWorker.cs:288 
[mono-rt]   at Sentry.Internal.BackgroundWorker.FlushAsync (System.TimeSpan timeout) [0x000c3] in /_/src/Sentry/Internal/BackgroundWorker.cs:220 
[mono-rt]   at Sentry.Internal.BackgroundWorker.FlushAsync (System.TimeSpan timeout) [0x00238] in /_/src/Sentry/Internal/BackgroundWorker.cs:236 
[mono-rt]   at Sentry.Internal.Hub.Dispose () [0x00020] in /_/src/Sentry/Internal/Hub.cs:431 
[mono-rt]   at Sentry.SentrySdk.UseHub (Sentry.IHub hub) [0x0000b] in /_/src/Sentry/SentrySdk.cs:114 
[mono-rt]   at Sentry.SentrySdk.Init (Sentry.SentryOptions options) [0x00000] in /_/src/Sentry/SentrySdk.cs:109 
[mono-rt]   at Sentry.SentryXamarin.Init (Sentry.SentryXamarinOptions options) [0x00000] in D:\a\sentry-xamarin\sentry-xamarin\Src\Sentry.Xamarin\SentryXamarin.cs:46 
[mono-rt]   at Sentry.SentryXamarin.Init (System.Action`1[T] configureOptions) [0x00080] in D:\a\sentry-xamarin\sentry-xamarin\Src\Sentry.Xamarin\SentryXamarin.cs:37 
[mono-rt]   at com.package.packagename.Utils.AndroidSentryHandler.InitSentry () [0x00013] in AndroidSentryHandler.cs:76 
[mono-rt]   at package.packagename.Utils.AndroidSentryHandler..ctor () [0x00008] in AndroidSentryHandler.cs:17 
[mono-rt]   at package.packagename.SplashActivity.Initialize () [0x0001e] in SplashActivity.cs:255 
[mono-rt]   at package.packagename.SplashActivity.OnCreate (Android.OS.Bundle savedInstanceState) [0x00163] in SplashActivity.cs:107 
[mono-rt]   at System.Runtime.CompilerServices.AsyncMethodBuilderCore+<>c.<ThrowAsync>b__7_0 (System.Object state) [0x00000] in /Users/builder/jenkins/workspace/archive-mono/2020-02/android/release/mcs/class/referencesource/mscorlib/system/runtime/compilerservices/AsyncMethodBuilder.cs:1021 
[mono-rt]   at Android.App.SyncContext+<>c__DisplayClass2_0.<Post>b__0 () [0x00000] in /Users/runner/work/1/s/xamarin-android/src/Mono.Android/Android.App/SyncContext.cs:36 
[mono-rt]   at Java.Lang.Thread+RunnableImplementor.Run () [0x00008] in /Users/runner/work/1/s/xamarin-android/src/Mono.Android/Java.Lang/Thread.cs:36 
[mono-rt]   at Java.Lang.IRunnableInvoker.n_Run (System.IntPtr jnienv, System.IntPtr native__this) [0x00008] in /Users/runner/work/1/s/xamarin-android/src/Mono.Android/obj/Release/monoandroid10/android-30/mcw/Java.Lang.IRunnable.cs:84 
[mono-rt]   at Android.Runtime.JNINativeWrapper.Wrap_JniMarshal_PP_V (_JniMarshal_PP_V callback, System.IntPtr jnienv, System.IntPtr klazz) [0x00005] in /Users/runner/work/1/s/xamarin-android/src/Mono.Android/Android.Runtime/JNINativeWrapper.g.cs:22 
[mono-rt]   at (wrapper native-to-managed) Android.Runtime.JNINativeWrapper.Wrap_JniMarshal_PP_V(intptr,intptr)

[mattjohnsonpint]

A sharing violation would indicate that more than one thread is trying to access the same file simultaneously, which would be quite strange indeed.

I've not seen any other reports of this, neither with Xamarin nor any other .NET project types.

When you say "Init should be re-called" - this should only happen if you're actually entering the onCreate stage again - which should only happen if the app was completely terminated the first time.

From the Android docs here:

Sentry should be initialized in onCreate (of the main activity), not in onStart, onResume, onRestart or the onCreate of an activity other than the main one for the app.

I do see SplashActivity.OnCreate in your call stack, but I'm not sure whether that's the main activity of your application (such as MainActivity we show in our readme), or if that's being launched from somewhere else. Perhaps you are launching your splash screen from onRestart? Can you clarify, and perhaps put a more complete example together?

Thanks.

[mattjohnsonpint]

@lucas-zimerman - Are you available to help investigate? Thanks.

[lucas-zimerman]

@lucas-zimerman - Are you available to help investigate? Thanks.

Sure. But here are a few questions in advance.

• Which Android version have you spotted this issue?
• How are you restarting the app?

One assumption that I have is that the app is partially restarted (the Android activity is restarted but the .NET code stays unchanged)

Ideally the SDK shouldn't crash the app when SentryXamarin.Init is invoked but I'll investigate what could be causing this issue.

[khalilyamoun]

@mattjohnsonpint @lucas-zimerman - Here's what's happening.

• In SplashActivity (or App's MainLauncher activity), Init the SDK in OnCreate
• Navigate from SplashActivity to a DummyActivity where you log events, exceptions, etc (just to fill up the cache / create multiple envelopes)
• Hit Android OS's back button to leave the app
• DummyActivity should be visible on Recent's screen, but when you tap on it, SplashActivity gets displayed and OnCreate gets called - that's what I mean by "Init should be re-called". It actually means that SplashActivity was destroyed and the Android Application continues running (e.g : Static fields in a DummyHelper class will keep their values) => In multiple cases, this crashes the app with the exception I already posted.

Keep in mind that :

• All Android versions are impacted
• The issue appeared just after updating to Xamarin.Sentry version 1.4.3 (Sentry .Net SDK version 3.22.0)
• It is all good when leaving the app via the Home button and relaunching it from the Recent's screen.
• We fixed the issue by testing whether the SDK isEnabled or not before Initializing Sentry.

[khalilyamoun]

@mattjohnsonpint, when you say "I've not seen any other reports of this, neither with Xamarin nor any other .NET project types."

• This exception doesn't get reported anywhere if you are not using another Application Monitoring / Error Tracking Software. In our case, we are still and we will continue to use our old trusted, but feature-limited SDK along with Sentry until we are sure that Sentry is 100% stable 😊

[mattjohnsonpint]

Thanks for the detailed response. I'm glad you found a workaround, but I'd still like to get this resolved fully.

It does sound like you're initializing Sentry when it is already initialized. Ideally you'd only be initializing once.

One quick test you can do is to check SentrySdk.IsEnabled, such as:

if (!SentrySdk.IsEnabled)
{
    SentryXamarin.Init(... your init options ...);
}

This won't hurt, but it shouldn't be required, as we detect and handle such a condition internally.

You say that it started after updating to Sentry.Xamarin 1.4.3. Can you please tell me which version you ran before that? When did it last work?

Thanks.

[mattjohnsonpint]

I did a bit more investigation, and indeed if Sentry is initialized twice with caching enabled, there is a potential for conflict on the cache files. This could manifest as a sharing violation on Android. See https://github.com/getsentry/sentry-dotnet/issues/2033 for more details.

We'll leave this open for Sentry.Xamarin and re-visit after resolving that.

Thanks.