Revert: Implement process and instance isolation (#4787)

* Revert: Implement process and instance isolation

Resolves #4775
- #4775

* Fix broken changelog

Author: jamescrosswell

CHANGELOG.md

@@ -75,7 +75,6 @@
 - QOL features for Unity
   - The SDK now provides a `IsSessionActive` to allow checking the session state ([#4662](https://github.com/getsentry/sentry-dotnet/pull/4662))
   - The SDK now makes use of the new SessionEndStatus `Unhandled` when capturing an unhandled but non-terminal exception, i.e. through the UnobservedTaskExceptionIntegration ([#4633](https://github.com/getsentry/sentry-dotnet/pull/4633), [#4653](https://github.com/getsentry/sentry-dotnet/pull/4653))
-- Implemented instance isolation so that multiple instances of the Sentry SDK can be instantiated inside the same process when using the Caching Transport ([#4498](https://github.com/getsentry/sentry-dotnet/pull/4498))
 - Extended the App context by `app_memory` that can hold the amount of memory used by the application in bytes. ([#4707](https://github.com/getsentry/sentry-dotnet/pull/4707))
 - Add support for W3C traceparent header for outgoing requests ([#4661](https://github.com/getsentry/sentry-dotnet/pull/4661))
   - This feature is disabled by default. Set `PropagateTraceparent = true` when initializing the SDK if to include the W3C traceparent header on outgoing requests.

src/Sentry/GlobalSessionManager.cs

@@ -33,7 +33,10 @@ public GlobalSessionManager(
         _clock = clock ?? SystemClock.Clock;
         _persistedSessionProvider = persistedSessionProvider
                                     ?? (filePath => Json.Load(_options.FileSystem, filePath, PersistedSessionUpdate.FromJson));
-        _persistenceDirectoryPath = options.GetIsolatedCacheDirectoryPath();
+
+        // TODO: session file should really be process-isolated, but we
+        // don't have a proper mechanism for that right now.
+        _persistenceDirectoryPath = options.TryGetDsnSpecificCacheDirectoryPath();
     }
 
     // Take pause timestamp directly instead of referencing _lastPauseTimestamp to avoid

src/Sentry/Internal/CacheDirectoryCoordinator.cs

@@ -2,9 +2,6 @@ namespace Sentry.Internal;
 
 internal abstract class FileSystemBase : IFileSystem
 {
-    public IEnumerable<string> EnumerateDirectories(string path, string searchPattern) =>
-        Directory.EnumerateDirectories(path, searchPattern);
-
     public IEnumerable<string> EnumerateFiles(string path) => Directory.EnumerateFiles(path);
 
     public IEnumerable<string> EnumerateFiles(string path, string searchPattern) =>
@@ -26,7 +23,6 @@ public IEnumerable<string> EnumerateFiles(string path, string searchPattern, Sea
     public abstract bool CreateDirectory(string path);
     public abstract bool DeleteDirectory(string path, bool recursive = false);
     public abstract bool CreateFileForWriting(string path, out Stream fileStream);
-    public abstract bool TryCreateLockFile(string path, out Stream fileStream);
     public abstract bool WriteAllTextToFile(string path, string contents);
     public abstract bool MoveFile(string sourceFileName, string destFileName, bool overwrite = false);
     public abstract bool DeleteFile(string path);