From 48b4819b9531b68ea7e2c468f341ebf58f5f8df7 Mon Sep 17 00:00:00 2001
From: Anairkoen Schno <aaron.cirr.com@gmail.com>
Date: Wed, 11 Dec 2019 21:52:38 -0600
Subject: [PATCH] Moved end-of-process saving into ConfigRuntime itself

---
 IPA.Loader/Config/Config.cs          |   1 +
 IPA.Loader/Config/ConfigRuntime.cs   | 101 +++++++++++++++++++--------
 IPA.Loader/Loader/PluginComponent.cs |   2 -
 3 files changed, 74 insertions(+), 30 deletions(-)

diff --git a/IPA.Loader/Config/Config.cs b/IPA.Loader/Config/Config.cs
index fd4b1610..e3860b9b 100644
--- a/IPA.Loader/Config/Config.cs
+++ b/IPA.Loader/Config/Config.cs
@@ -139,6 +139,7 @@ namespace IPA.Config
 
         internal IConfigStore Store = null;
         internal readonly FileInfo File;
+        internal int Writes = 0;
 
         /// <summary>
         /// Sets this object's <see cref="IConfigStore"/>. Can only be called once.
diff --git a/IPA.Loader/Config/ConfigRuntime.cs b/IPA.Loader/Config/ConfigRuntime.cs
index 7fb35ef3..2bd908bb 100644
--- a/IPA.Loader/Config/ConfigRuntime.cs
+++ b/IPA.Loader/Config/ConfigRuntime.cs
@@ -10,6 +10,10 @@ using IPA.Utilities.Async;
 using System.IO;
 using System.Runtime.CompilerServices;
 using IPA.Logging;
+#if NET4
+using Task = System.Threading.Tasks.Task;
+using TaskEx = System.Threading.Tasks.Task;
+#endif
 
 namespace IPA.Config
 {
@@ -49,6 +53,24 @@ namespace IPA.Config
                 saveThread = new Thread(SaveThread);
                 saveThread.Start();
             }
+
+            AppDomain.CurrentDomain.ProcessExit -= ShutdownRuntime;
+            AppDomain.CurrentDomain.ProcessExit += ShutdownRuntime;
+        }
+
+        private static void ShutdownRuntime(object sender, EventArgs e)
+        {
+            watcherTrackConfigs.Clear();
+            var watchList = watchers.ToArray();
+            watchers.Clear();
+
+            foreach (var pair in watchList)
+                pair.Value.EnableRaisingEvents = false;
+
+            loadScheduler.Join(); // we can wait for the loads to finish
+            saveThread.Abort(); // eww, but i don't like any of the other potential solutions
+
+            SaveAll();
         }
 
         public static void RegisterConfig(Config cfg)
@@ -107,25 +129,31 @@ namespace IPA.Config
 
         }
 
+        private static void EnsureWritesSane(Config config)
+        {
+            // compare exchange loop to be sane
+            var writes = config.Writes;
+            while (writes < 0)
+                writes = Interlocked.CompareExchange(ref config.Writes, 0, writes);
+        }
+
         private static void FileChangedEvent(object sender, FileSystemEventArgs e)
         {
             var watcher = sender as FileSystemWatcher;
             if (!watcherTrackConfigs.TryGetValue(watcher, out var bag)) return;
 
             var config = bag.FirstOrDefault(c => c.File.FullName == e.FullPath);
-            if (config != null)
+            if (config != null && Interlocked.Decrement(ref config.Writes) + 1 > 0)
+            {
+                EnsureWritesSane(config);
                 TriggerFileLoad(config);
+            }
         }
 
         public static Task TriggerFileLoad(Config config) => loadFactory.StartNew(() => LoadTask(config));
 
         public static Task TriggerLoadAll() =>
-#if NET3
-            TaskEx
-#else
-            Task
-#endif
-            .WhenAll(configs.Select(TriggerFileLoad));
+            TaskEx.WhenAll(configs.Select(TriggerFileLoad));
 
         /// <summary>
         /// this is synchronous, unlike <see cref="TriggerFileLoad(Config)"/>
@@ -141,9 +169,15 @@ namespace IPA.Config
                 lock (config.Provider)
                 {
                     config.Provider.File = config.File;
+                    EnsureWritesSane(config);
+                    Interlocked.Increment(ref config.Writes);
                     store.WriteTo(config.Provider);
                 }
             }
+            catch (ThreadAbortException)
+            {
+                throw;
+            }
             catch (Exception e)
             {
                 Logger.config.Error($"{nameof(IConfigStore)} for {config.File} errored while writing to disk");
@@ -181,31 +215,42 @@ namespace IPA.Config
 
         private static void SaveThread()
         {
-            while (true)
+            try
             {
-                var configArr = configs.Where(c => c.Store != null).ToArray();
-                int index = -1;
-                try
-                {
-                    var waitHandles = configArr.Select(c => c.Store.SyncObject)
-                                             .Prepend(configsChangedWatcher)
-                                             .ToArray();
-                    index = WaitHandle.WaitAny(waitHandles);
-                }
-                catch (Exception e)
+                while (true)
                 {
-                    Logger.config.Error($"Error waiting for in-memory updates");
-                    Logger.config.Error(e);
-                    Thread.Sleep(TimeSpan.FromSeconds(1));
-                }
+                    var configArr = configs.Where(c => c.Store != null).ToArray();
+                    int index = -1;
+                    try
+                    {
+                        var waitHandles = configArr.Select(c => c.Store.SyncObject)
+                                                 .Prepend(configsChangedWatcher)
+                                                 .ToArray();
+                        index = WaitHandle.WaitAny(waitHandles);
+                    }
+                    catch (ThreadAbortException)
+                    {
+                        break;
+                    }
+                    catch (Exception e)
+                    {
+                        Logger.config.Error($"Error waiting for in-memory updates");
+                        Logger.config.Error(e);
+                        Thread.Sleep(TimeSpan.FromSeconds(1));
+                    }
 
-                if (index <= 0)
-                { // we got a signal that the configs collection changed, loop around, or errored
-                    continue;
-                }
+                    if (index <= 0)
+                    { // we got a signal that the configs collection changed, loop around, or errored
+                        continue;
+                    }
 
-                // otherwise, we have a thing that changed in a store
-                Save(configArr[index - 1]);
+                    // otherwise, we have a thing that changed in a store
+                    Save(configArr[index - 1]);
+                }
+            }
+            catch (ThreadAbortException)
+            {
+                // we got aborted :(
             }
         }
     }
diff --git a/IPA.Loader/Loader/PluginComponent.cs b/IPA.Loader/Loader/PluginComponent.cs
index 92bfe8b9..61a71001 100644
--- a/IPA.Loader/Loader/PluginComponent.cs
+++ b/IPA.Loader/Loader/PluginComponent.cs
@@ -76,8 +76,6 @@ namespace IPA.Loader
             bsPlugins.OnApplicationQuit();
             ipaPlugins.OnApplicationQuit();
 
-            ConfigRuntime.SaveAll();
-
             quitting = true;
         }