System.IO.IOException: The process cannot access the file "path/to/file" because it is being used by another process

[PeterKvayt]

I use umbraco 10.8.2, which is use Smidge 4.2.1

I faced with following exception: An unhandled exception has occurred while executing the request.

System.IO.IOException: The process cannot access the file 'C:\home\site\wwwroot\Smidge\Cache\{machine name}\92ee6281ad3366850c9d45e154f82540c3cbee8a\gzip\umbraco-backoffice-js.s' because it is being used by another process.
at Microsoft.Win32.SafeHandles.SafeFileHandle.CreateFile(String fullPath, FileMode mode, FileAccess access, FileShare share, FileOptions options)
at Microsoft.Win32.SafeHandles.SafeFileHandle.Open(String fullPath, FileMode mode, FileAccess access, FileShare share, FileOptions options, Int64 preallocationSize)
at System.IO.Strategies.OSFileStreamStrategy..ctor(String path, FileMode mode, FileAccess access, FileShare share, FileOptions options, Int64 preallocationSize)
at System.IO.Strategies.FileStreamHelpers.ChooseStrategy(FileStream fileStream, String path, FileMode mode, FileAccess access, FileShare share, Int32 bufferSize, FileOptions options, Int64 preallocationSize)
at System.IO.File.Create(String path)
at Smidge.Cache.PhysicalFileCacheFileSystem.WriteFileAsync(String filePath, Stream contents)
at Smidge.Controllers.SmidgeController.CacheCompositeFileAsync(ICacheFileSystem cacheProvider, String filePath, Stream compositeStream)
at Smidge.Controllers.SmidgeController.Bundle(BundleRequestModel bundleModel)
at Microsoft.AspNetCore.Mvc.Infrastructure.ActionMethodExecutor.TaskOfIActionResultExecutor.Execute(IActionResultTypeMapper mapper, ObjectMethodExecutor executor, Object controller, Object[] arguments)
at Microsoft.AspNetCore.Mvc.Infrastructure.ControllerActionInvoker.g__Awaited|12_0(ControllerActionInvoker invoker, ValueTask`1 actionResultValueTask)
at Microsoft.AspNetCore.Mvc.Infrastructure.ControllerActionInvoker.g__Awaited|10_0(ControllerActionInvoker invoker, Task lastTask, State next, Scope scope, Object state, Boolean isCompleted)
at Microsoft.AspNetCore.Mvc.Infrastructure.ControllerActionInvoker.Rethrow(ActionExecutedContextSealed context)
at Microsoft.AspNetCore.Mvc.Infrastructure.ControllerActionInvoker.Next(State& next, Scope& scope, Object& state, Boolean& isCompleted)
at Microsoft.AspNetCore.Mvc.Infrastructure.ControllerActionInvoker.g__Awaited|13_0(ControllerActionInvoker invoker, Task lastTask, State next, Scope scope, Object state, Boolean isCompleted)
at Microsoft.AspNetCore.Mvc.Infrastructure.ResourceInvoker.g__Awaited|25_0(ResourceInvoker invoker, Task lastTask, State next, Scope scope, Object state, Boolean isCompleted)
at Microsoft.AspNetCore.Mvc.Infrastructure.ResourceInvoker.Rethrow(ResourceExecutedContextSealed context)
at Microsoft.AspNetCore.Mvc.Infrastructure.ResourceInvoker.Next(State& next, Scope& scope, Object& state, Boolean& isCompleted)
at Microsoft.AspNetCore.Mvc.Infrastructure.ResourceInvoker.g__Awaited|20_0(ResourceInvoker invoker, Task lastTask, State next, Scope scope, Object state, Boolean isCompleted)
at Microsoft.AspNetCore.Mvc.Infrastructure.ResourceInvoker.g__Awaited|17_0(ResourceInvoker invoker, Task task, IDisposable scope)
(stack trace skipped)

This exception was thrown during executing two or more requests which triggered "/sb/umbraco-backoffice-js.js.v92ee6281ad3366850c9d45e154f82540c3cbee8a" url. This url is Bundle action.

As i can see to fix it we should to implement sort lock here or as alternative solution start using polly to retry creating a cache on exception.

[Shazwazza]

Yep looks like you hit a race condition issue. A quick solution would be to add a lock in the Smidge.Cache.PhysicalFileCacheFileSystem.WriteFileAsync

Also, looking at the path it is erroring on, there's a configuration bug occurring somewhere:

C:\home\site\wwwroot\Smidge\Cache{nachine name}\92ee6281ad3366850c9d45e154f82540c3cbee8a\gzip\umbraco-backoffice-js.s

... the {nachine name} part is not right and I'm not sure where that is coming from.

I'll look into adding a lock now.

[Shazwazza]

@PeterKvayt Can you please review #211?

[PeterKvayt]

@Shazwazza Thanks for the fast reply. I will review your fix when I have free time.

... the {nachine name} part is not right and I'm not sure where that is coming from.

It was a typo. I have fixed the original comment.

[Shazwazza]

I am going to go ahead and merge this, local and unit tests are passing.