From 58bd223a80f116b51500b8950b9d6fd989970b51 Mon Sep 17 00:00:00 2001
From: Ottermandias <nickroederspam+git1@gmail.com>
Date: Tue, 2 May 2023 18:02:32 +0200
Subject: [PATCH] Make cache calculation thread safe(r)

---
 .../Cache/CollectionCacheManager.cs           | 41 +++++++++++--------
 1 file changed, 25 insertions(+), 16 deletions(-)

diff --git a/Penumbra/Collections/Cache/CollectionCacheManager.cs b/Penumbra/Collections/Cache/CollectionCacheManager.cs
index 088c3a90..d5df7d7d 100644
--- a/Penumbra/Collections/Cache/CollectionCacheManager.cs
+++ b/Penumbra/Collections/Cache/CollectionCacheManager.cs
@@ -27,7 +27,8 @@ public class CollectionCacheManager : IDisposable
 
     internal readonly MetaFileManager MetaFileManager;
 
-    public int Count { get; private set; }
+    public int  Count       { get; private set; }
+    public bool Calculating { get; private set; }
 
     public IEnumerable<ModCollection> Active
         => _storage.Where(c => c.HasCache);
@@ -116,28 +117,36 @@ public class CollectionCacheManager : IDisposable
     private void FullRecalculation(ModCollection collection)
     {
         var cache = collection._cache;
-        if (cache == null)
+        if (cache == null || Calculating)
             return;
 
-        cache.ResolvedFiles.Clear();
-        cache.Meta.Reset();
-        cache._conflicts.Clear();
+        Calculating = true;
+        try
+        {
+            cache.ResolvedFiles.Clear();
+            cache.Meta.Reset();
+            cache._conflicts.Clear();
 
-        // Add all forced redirects.
-        foreach (var tempMod in _tempMods.ModsForAllCollections
-                     .Concat(_tempMods.Mods.TryGetValue(collection, out var list)
-                         ? list
-                         : Array.Empty<TemporaryMod>()))
-            cache.AddMod(tempMod, false);
+            // Add all forced redirects.
+            foreach (var tempMod in _tempMods.ModsForAllCollections
+                         .Concat(_tempMods.Mods.TryGetValue(collection, out var list)
+                             ? list
+                             : Array.Empty<TemporaryMod>()))
+                cache.AddMod(tempMod, false);
 
-        foreach (var mod in _modStorage)
-            cache.AddMod(mod, false);
+            foreach (var mod in _modStorage)
+                cache.AddMod(mod, false);
 
-        cache.AddMetaFiles();
+            cache.AddMetaFiles();
 
-        ++collection.ChangeCounter;
+            ++collection.ChangeCounter;
 
-        MetaFileManager.ApplyDefaultFiles(collection);
+            MetaFileManager.ApplyDefaultFiles(collection);
+        }
+        finally
+        {
+            Calculating = false;
+        }
     }
 
     private void OnCollectionChange(CollectionType type, ModCollection? old, ModCollection? newCollection, string displayName)