Better Fallback Handling for Weird Locker Helper Disposed Issue

chummer5a · Mar 9, 2024 · d7c1864 · d7c1864
1 parent dec7d11
commit d7c1864
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Showing 2 changed files with 37 additions and 42 deletions.
diff --git a/Chummer/Backend/Helpers/AsyncFriendlyReaderWriterLock.cs b/Chummer/Backend/Helpers/AsyncFriendlyReaderWriterLock.cs
@@ -174,8 +174,8 @@ LinkedAsyncRWLockHelper> GetHelpers(CancellationToken token = default)
         {
             token.ThrowIfCancellationRequested();
             LinkedAsyncRWLockHelper objCurrentHelper = _objTopLevelHelper;
-            LinkedAsyncRWLockHelper objTopMostHeldUReader;
-            LinkedAsyncRWLockHelper objTopMostHeldWriter;
+            LinkedAsyncRWLockHelper objTopMostHeldUReader = null;
+            LinkedAsyncRWLockHelper objTopMostHeldWriter = null;
             LinkedAsyncRWLockHelper objNextHelper;
 #if ASYNCLOCALWRITEDEBUG
             string strLastWriteStacktrace = string.Empty;
@@ -189,38 +189,43 @@ LinkedAsyncRWLockHelper> GetHelpers(CancellationToken token = default)
                 {
                     // Emergency exit for odd cases where, for some reason, AsyncLocal assignment does not happen (in the right place?) when a locker release is disposed
                     Utils.BreakIfDebug();
-                    // Let's just get the helpers of the top-level lock. If this causes problems, it's because of the above-mentioned comment around AsyncLocal assignment
-#if ASYNCLOCALWRITEDEBUG
+                    // Let's just get the first ancestor lock that is not disposed. If this causes problems, it's because of the above-mentioned comment around AsyncLocal assignment
+                    while (objCurrentHelper != null && objCurrentHelper.IsDisposed)
+                        objCurrentHelper = objCurrentHelper.ParentLinkedHelper;
+                    while (objTopMostHeldUReader != null && objTopMostHeldUReader.IsDisposed)
+                        objTopMostHeldUReader = objTopMostHeldUReader.ParentLinkedHelper;
+                    while (objTopMostHeldWriter != null && objTopMostHeldWriter.IsDisposed)
+                        objTopMostHeldWriter = objTopMostHeldWriter.ParentLinkedHelper;
                     _objAsyncLocalCurrentsContainer.Value =
-                        new Tuple<LinkedAsyncRWLockHelper, LinkedAsyncRWLockHelper, LinkedAsyncRWLockHelper, string>(_objTopLevelHelper, null, null, Environment.StackTrace);
+#if ASYNCLOCALWRITEDEBUG
+                        new Tuple<LinkedAsyncRWLockHelper, LinkedAsyncRWLockHelper, LinkedAsyncRWLockHelper, string>(objCurrentHelper, objTopMostHeldUReader, objTopMostHeldWriter, Environment.StackTrace);
 #else
-                    _objAsyncLocalCurrentsContainer.Value =
-                        new Tuple<LinkedAsyncRWLockHelper, LinkedAsyncRWLockHelper, LinkedAsyncRWLockHelper>(_objTopLevelHelper, null, null);
+                        new Tuple<LinkedAsyncRWLockHelper, LinkedAsyncRWLockHelper, LinkedAsyncRWLockHelper>(objCurrentHelper, objTopMostHeldUReader, objTopMostHeldWriter);
 #endif
-                    objCurrentHelper = _objTopLevelHelper;
-                    objTopMostHeldUReader = null;
-                    objTopMostHeldWriter = null;
-                    objNextHelper = new LinkedAsyncRWLockHelper(objCurrentHelper);
                 }
+                else
+                {
 #if ASYNCLOCALWRITEDEBUG
-                Tuple<LinkedAsyncRWLockHelper, LinkedAsyncRWLockHelper, LinkedAsyncRWLockHelper, string>
+                    Tuple<LinkedAsyncRWLockHelper, LinkedAsyncRWLockHelper, LinkedAsyncRWLockHelper, string>
 #else
-                Tuple<LinkedAsyncRWLockHelper, LinkedAsyncRWLockHelper, LinkedAsyncRWLockHelper>
+                    Tuple<LinkedAsyncRWLockHelper, LinkedAsyncRWLockHelper, LinkedAsyncRWLockHelper>
 #endif
-                    objAsyncLocals = _objAsyncLocalCurrentsContainer.Value;
-                if (objAsyncLocals != null)
-                {
+                        objAsyncLocals = _objAsyncLocalCurrentsContainer.Value;
+                    if (objAsyncLocals != null)
+                    {
 #if ASYNCLOCALWRITEDEBUG
-                    (objCurrentHelper, objTopMostHeldUReader, objTopMostHeldWriter, strLastWriteStacktrace) = objAsyncLocals;
+                        (objCurrentHelper, objTopMostHeldUReader, objTopMostHeldWriter, strLastWriteStacktrace)
 #else
-                    (objCurrentHelper, objTopMostHeldUReader, objTopMostHeldWriter) = objAsyncLocals;
+                        (objCurrentHelper, objTopMostHeldUReader, objTopMostHeldWriter)
 #endif
-                }
-                else
-                {
-                    objCurrentHelper = _objTopLevelHelper;
-                    objTopMostHeldUReader = null;
-                    objTopMostHeldWriter = null;
+                            = objAsyncLocals;
+                    }
+                    else
+                    {
+                        objCurrentHelper = _objTopLevelHelper;
+                        objTopMostHeldUReader = null;
+                        objTopMostHeldWriter = null;
+                    }
                 }
 
                 if (objCurrentHelper.IsDisposed)
@@ -270,12 +275,11 @@ public IDisposable EnterWriteLock(CancellationToken token = default)
                 objCurrentHelper.TakeWriteLock(objTopMostHeldWriter, token);
                 try
                 {
-#if ASYNCLOCALWRITEDEBUG
                     _objAsyncLocalCurrentsContainer.Value =
+#if ASYNCLOCALWRITEDEBUG
                         new Tuple<LinkedAsyncRWLockHelper, LinkedAsyncRWLockHelper, LinkedAsyncRWLockHelper, string>(
                             objNextHelper, objTopMostHeldUReader, objCurrentHelper, Environment.StackTrace);
 #else
-                    _objAsyncLocalCurrentsContainer.Value =
                         new Tuple<LinkedAsyncRWLockHelper, LinkedAsyncRWLockHelper, LinkedAsyncRWLockHelper>(
                             objNextHelper, objTopMostHeldUReader, objCurrentHelper);
 #endif
@@ -299,12 +303,11 @@ public IDisposable EnterWriteLock(CancellationToken token = default)
                     }
                     catch
                     {
-#if ASYNCLOCALWRITEDEBUG
                         _objAsyncLocalCurrentsContainer.Value =
+#if ASYNCLOCALWRITEDEBUG
                             new Tuple<LinkedAsyncRWLockHelper, LinkedAsyncRWLockHelper, LinkedAsyncRWLockHelper, string>(
                                 objCurrentHelper, objTopMostHeldUReader, objTopMostHeldWriter, Environment.StackTrace);
 #else
-                        _objAsyncLocalCurrentsContainer.Value =
                             new Tuple<LinkedAsyncRWLockHelper, LinkedAsyncRWLockHelper, LinkedAsyncRWLockHelper>(
                                 objCurrentHelper, objTopMostHeldUReader, objTopMostHeldWriter);
 #endif
@@ -372,12 +375,11 @@ public Task<IAsyncDisposable> EnterWriteLockAsync(CancellationToken token = defa
                 return Task.FromException<IAsyncDisposable>(e);
             }
 
-#if ASYNCLOCALWRITEDEBUG
             _objAsyncLocalCurrentsContainer.Value =
+#if ASYNCLOCALWRITEDEBUG
                 new Tuple<LinkedAsyncRWLockHelper, LinkedAsyncRWLockHelper, LinkedAsyncRWLockHelper, string>(
                     objNextHelper, objTopMostHeldUReader, objCurrentHelper, Environment.StackTrace);
 #else
-            _objAsyncLocalCurrentsContainer.Value =
                 new Tuple<LinkedAsyncRWLockHelper, LinkedAsyncRWLockHelper, LinkedAsyncRWLockHelper>(
                     objNextHelper, objTopMostHeldUReader, objCurrentHelper);
 #endif
@@ -465,12 +467,11 @@ public IDisposable EnterUpgradeableReadLock(CancellationToken token = default)
                 objCurrentHelper.TakeUpgradeableReadLock(token);
                 try
                 {
-#if ASYNCLOCALWRITEDEBUG
                     _objAsyncLocalCurrentsContainer.Value =
+#if ASYNCLOCALWRITEDEBUG
                         new Tuple<LinkedAsyncRWLockHelper, LinkedAsyncRWLockHelper, LinkedAsyncRWLockHelper, string>(
                             objNextHelper, objCurrentHelper, objTopMostHeldWriter, Environment.StackTrace);
 #else
-                    _objAsyncLocalCurrentsContainer.Value =
                         new Tuple<LinkedAsyncRWLockHelper, LinkedAsyncRWLockHelper, LinkedAsyncRWLockHelper>(
                             objNextHelper, objCurrentHelper, objTopMostHeldWriter);
 #endif
@@ -495,12 +496,11 @@ public IDisposable EnterUpgradeableReadLock(CancellationToken token = default)
                     }
                     catch
                     {
-#if ASYNCLOCALWRITEDEBUG
                         _objAsyncLocalCurrentsContainer.Value =
+#if ASYNCLOCALWRITEDEBUG
                             new Tuple<LinkedAsyncRWLockHelper, LinkedAsyncRWLockHelper, LinkedAsyncRWLockHelper, string>(
                                 objCurrentHelper, objTopMostHeldUReader, objTopMostHeldWriter, Environment.StackTrace);
 #else
-                        _objAsyncLocalCurrentsContainer.Value =
                             new Tuple<LinkedAsyncRWLockHelper, LinkedAsyncRWLockHelper, LinkedAsyncRWLockHelper>(
                                 objCurrentHelper, objTopMostHeldUReader, objTopMostHeldWriter);
 #endif
@@ -566,12 +566,11 @@ public Task<IAsyncDisposable> EnterUpgradeableReadLockAsync(CancellationToken to
                 return Task.FromException<IAsyncDisposable>(e);
             }
 
-#if ASYNCLOCALWRITEDEBUG
             _objAsyncLocalCurrentsContainer.Value =
+#if ASYNCLOCALWRITEDEBUG
                 new Tuple<LinkedAsyncRWLockHelper, LinkedAsyncRWLockHelper, LinkedAsyncRWLockHelper, string>(
                     objNextHelper, objCurrentHelper, objTopMostHeldWriter, Environment.StackTrace);
 #else
-            _objAsyncLocalCurrentsContainer.Value =
                 new Tuple<LinkedAsyncRWLockHelper, LinkedAsyncRWLockHelper, LinkedAsyncRWLockHelper>(
                     objNextHelper, objCurrentHelper, objTopMostHeldWriter);
 #endif

diff --git a/Chummer/Backend/Helpers/LinkedAsyncRWLockHelper.cs b/Chummer/Backend/Helpers/LinkedAsyncRWLockHelper.cs
@@ -46,11 +46,7 @@ public sealed class LinkedAsyncRWLockHelper : IDisposable, IAsyncDisposable
         private int _intNumChildren;
         private DebuggableSemaphoreSlim _objHasChildrenSemaphore; // Used to prevent disposing a helper until it has no more children left
 
-#if LINKEDSEMAPHOREDEBUG
         private readonly LinkedAsyncRWLockHelper _objParentLinkedHelper;
-#else
-        private LinkedAsyncRWLockHelper _objParentLinkedHelper;
-#endif
         private readonly CancellationTokenSource _objDisposalTokenSource = new CancellationTokenSource();
         private readonly CancellationToken _objDisposalToken;
 
@@ -273,7 +269,7 @@ public void Dispose()
 #if LINKEDSEMAPHOREDEBUG
             _objParentLinkedHelper?.RemoveChild(this);
 #else
-            Interlocked.Exchange(ref _objParentLinkedHelper, null)?.RemoveChild();
+            _objParentLinkedHelper?.RemoveChild();
 #endif
 
             // Progressively release and dispose of our locks
@@ -402,7 +398,7 @@ public async ValueTask DisposeAsync()
 #if LINKEDSEMAPHOREDEBUG
             _objParentLinkedHelper?.RemoveChild(this);
 #else
-            Interlocked.Exchange(ref _objParentLinkedHelper, null)?.RemoveChild();
+            _objParentLinkedHelper?.RemoveChild();
 #endif
 
             // Progressively release and dispose of our locks