OffScreen - NETCore PublishSingleFile as Background Service

[vinothtgithub]

• CefSharp.OffScreen.NETCore version 103.0.90

• x64 architecture

• .NET6

• Win10 operating system

• OffScreen

• Steps to reproduce the problem:

  • Created .NET6 Background Service project and copied the example code from "https://github.com/cefsharp/CefSharp.MinimalExample/CefSharp.MinimalExample.OffScreen/Program.cs". Configured to run in x64. When running this project in console mode, sample code works as expected. But when deployed as windows service, same sample code is not working as expected and throwing error during CEF library code execution,
  • The problem is reproducible using the MinimalExample and sample project is available in https://github.com/vinothtgithub/cefbgservice

• Expected output is screen shot of google search home page with key input "CefSharp Was Here!". But following error during service start

• Application: CEFSharpDemo.Net6.WokerService.exe
  CoreCLR Version: 6.0.622.26707
  .NET Version: 6.0.6
  Description: The process was terminated due to an internal error in the .NET Runtime.at IP 00007FF61C079BD4 (00007FF61BE30000) with exit code c0000005.

• Faulting application name: CEFSharpDemo.Net6.WokerService.exe, version: 1.0.0.0, time stamp: 0x6283da22
  Faulting module name: CEFSharpDemo.Net6.WokerService.exe, version: 1.0.0.0, time stamp: 0x6283da22
  Exception code: 0xc0000005
  Fault offset: 0x0000000000249bd4
  Faulting process id: 0x5190
  Faulting application start time: 0x01d8956193c5323b
  Faulting application path: C:\Users\xxxxxx\source\repos\CEFSharpDemo.Net6.WokerService\CEFSharpDemo.Net6.WokerService\bin\Release\net6.0\publish\CEFSharpDemo.Net6.WokerService.exe
  Faulting module path: C:\Users\xxxxxx\source\repos\CEFSharpDemo.Net6.WokerService\CEFSharpDemo.Net6.WokerService\bin\Release\net6.0\publish\CEFSharpDemo.Net6.WokerService.exe
  Report Id: 10d98fbb-247d-40e5-83e1-030dbfb8ea0f
  Faulting package full name:
  Faulting package-relative application ID:

[amaitland]

What is the actual error?

What settings did you publish with?

What settings did you install the service with?

[vinothtgithub]

Publish Settings:

<?xml version="1.0" encoding="utf-8"?>
<!--
https://go.microsoft.com/fwlink/?LinkID=208121.
-->
<Project>
  <PropertyGroup>
    <Configuration>Release</Configuration>
    <Platform>x64</Platform>
    <PublishDir>bin\Release\net6.0\publish\</PublishDir>
    <PublishProtocol>FileSystem</PublishProtocol>
    <TargetFramework>net6.0</TargetFramework>
    <RuntimeIdentifier>win-x64</RuntimeIdentifier>
    <SelfContained>true</SelfContained>
    <PublishSingleFile>true</PublishSingleFile>
    <PublishReadyToRun>true</PublishReadyToRun>
    <PublishTrimmed>false</PublishTrimmed>
  </PropertyGroup>
</Project>

[vinothtgithub]

Service installation has done using microsoft documentation https://docs.microsoft.com/en-us/dotnet/core/extensions/windows-service.

For service Installation, open Windows Powershell in Administrator mode

[USE SCRIPT TO CREATE SERVICE]
sc.exe create "Cef Browser Background Service" binPath="C:\Users\casee2009\source\repos\CEFSharpDemo.Net6.WokerService\CEFSharpDemo.Net6.WokerService\bin\Release\net6.0\publish\CEFSharpDemo.Net6.WokerService.exe"
[OUTPUT]
CreateService SUCCESS

[USE SCRIPT TO START SERVICE] ERROR IS REPRODUCIBLE IN THIS STEP
sc.exe start "Cef Browser Background Service"
[OUTPUT]
SERVICE_NAME: Cef Browser Background Service
TYPE : 10 WIN32_OWN_PROCESS
STATE : 2 START_PENDING
(NOT_STOPPABLE, NOT_PAUSABLE, IGNORES_SHUTDOWN)
WIN32_EXIT_CODE : 0 (0x0)
SERVICE_EXIT_CODE : 0 (0x0)
CHECKPOINT : 0x0
WAIT_HINT : 0x7d0
PID : 21508
FLAGS :

[amaitland]

I need the actual exception that's being thrown, not just the generic event log, attach the debugger to the process.

Publish Settings:

You must self host the browser sub process to publish a single file exe. There are details on the publish settings required and self hosting at #3407

You'll need to change your example. I'd suggest you start without publishing a self contained single file build and get that working first.

Service installation has done using microsoft documentation https://docs.microsoft.com/en-us/dotnet/core/extensions/windows-service.

The OffScreen example code is not meant to be run in a service and would require changes to the paths.

[vinothtgithub]

Thanks. Like you advised I copied the files from "x64/Debug" folder (which is a working version) and installed as service. its now running as background service and working as expected.

Actual Exception captured from console screen:

_info: CEFSharpDemo.Net6.WokerService.Worker[0]
Starting service
Fatal error. System.AccessViolationException: Attempted to read or write protected memory. This is often an indication that other memory is corrupt.
Repeat 2 times:
at ._getFiberPtrId()
at ..LanguageSupport.Initialize(.LanguageSupport*)
at ..LanguageSupport.Initialize(.LanguageSupport*)
at ..cctor()
at CefSharp.CefSettingsBase..ctor()
at CefSharp.OffScreen.CefSettings..ctor()
at CEFSharpDemo.Net6.WokerService.Worker+<b__2_0>d.MoveNext()
at System.Runtime.CompilerServices.AsyncMethodBuilderCore.Start[[CEFSharpDemo.Net6.WokerService.Worker+<b__2_0>d, CEFSharpDemo.Net6.WokerService, Version=1.0.0.0, Culture=neutral, PublicKeyToken=null]](<b__2_0>d ByRef)
at System.Runtime.CompilerServices.AsyncTaskMethodBuilder.Start[[CEFSharpDemo.Net6.WokerService.Worker+<b__2_0>d, CEFSharpDemo.Net6.WokerService, Version=1.0.0.0, Culture=neutral, PublicKeyToken=null]](<b__2_0>d ByRef)
at CEFSharpDemo.Net6.WokerService.Worker.b__2_0()
at CEFSharpDemo.Net6.WokerService.AsyncContext.Run(System.Func`1<System.Threading.Tasks.Task>)
at CEFSharpDemo.Net6.WokerService.Worker.ExecuteAsync(System.Threading.CancellationToken)
at Microsoft.Extensions.Hosting.BackgroundService.StartAsync(System.Threading.CancellationToken)
at Microsoft.Extensions.Hosting.Internal.Host+d__12.MoveNext()
at System.Runtime.CompilerServices.AsyncMethodBuilderCore.Start[[Microsoft.Extensions.Hosting.Internal.Host+d__12, Microsoft.Extensions.Hosting, Version=6.0.0.0, Culture=neutral, PublicKeyToken=adb9793829ddae60]](d__12 ByRef)
at System.Runtime.CompilerServices.AsyncTaskMethodBuilder.Start[[Microsoft.Extensions.Hosting.Internal.Host+d__12, Microsoft.Extensions.Hosting, Version=6.0.0.0, Culture=neutral, PublicKeyToken=adb9793829ddae60]](d__12 ByRef)
at Microsoft.Extensions.Hosting.Internal.Host.StartAsync(System.Threading.CancellationToken)
at Microsoft.Extensions.Hosting.HostingAbstractionsHostExtensions+d__4.MoveNext()
at System.Runtime.CompilerServices.AsyncMethodBuilderCore.Start[[Microsoft.Extensions.Hosting.HostingAbstractionsHostExtensions+d__4, Microsoft.Extensions.Hosting.Abstractions, Version=6.0.0.0, Culture=neutral, PublicKeyToken=adb9793829ddae60]](d__4 ByRef)
at System.Runtime.CompilerServices.AsyncTaskMethodBuilder.Start[[Microsoft.Extensions.Hosting.HostingAbstractionsHostExtensions+d__4, Microsoft.Extensions.Hosting.Abstractions, Version=6.0.0.0, Culture=neutral, PublicKeyToken=adb9793829ddae60]](d__4 ByRef)
at Microsoft.Extensions.Hosting.HostingAbstractionsHostExtensions.RunAsync(Microsoft.Extensions.Hosting.IHost, System.Threading.CancellationToken)
at Program+<

$>d__0.MoveNext()
at System.Runtime.CompilerServices.AsyncMethodBuilderCore.Start[[Program+<$>d__0, CEFSharpDemo.Net6.WokerService, Version=1.0.0.0, Culture=neutral, PublicKeyToken=null]](<$>d__0 ByRef)
at System.Runtime.CompilerServices.AsyncTaskMethodBuilder.Start[[Program+<$>d__0, CEFSharpDemo.Net6.WokerService, Version=1.0.0.0, Culture=neutral, PublicKeyToken=null]](<$>d__0 ByRef)
at Program.$(System.String[])
at Program.(System.String[])

I will refer the #3407 and make working version, then I will deploy it as background service

You must self host the browser sub process to publish a single file exe. There are details on the publish settings required and self hosting at https://github.com/cefsharp/CefSharp/issues/3407You must self host the browser sub process to publish a single file exe. There are details on the publish settings required and self hosting at #3407"

[amaitland]

Personally i see little benefit in publishing a single file for a service. Zipping the release output into a zip file which includes the build version in it's name and having a batch file for automation would be my preference. Much easier to troubleshoot.

https://docs.microsoft.com/en-us/visualstudio/msbuild/zipdirectory-task?view=vs-2022