fix(json,json-cppagent): cache JsonSerializerOptions singletons — plug DynamicMethod LCG leak (+3.2-3.8 MB/h RSS)

libraries/MTConnect.NET-Common/Agents/MTConnectAgentInformation.cs

@@ -19,6 +19,15 @@ public class MTConnectAgentInformation
         /// </summary>
         public const string Filename = "agent.information.json";
 
+        // Shared across every Save call. See JsonFunctions.cs for the
+        // rationale — a fresh JsonSerializerOptions per call re-emits
+        // LCG DynamicMethods into the loader heap, and the GC cannot
+        // reclaim them.
+        private static readonly JsonSerializerOptions _saveOptions = new JsonSerializerOptions
+        {
+            WriteIndented = true
+        };
+
 
         /// <summary>
         /// A token regenerated on every save, used to detect when the persisted information has changed.
@@ -127,12 +136,7 @@ public void Save(string path = null)
 
             try
             {
-                var options = new JsonSerializerOptions
-                {
-                    WriteIndented = true
-                };
-
-                var json = JsonSerializer.Serialize(this, options);
+                var json = JsonSerializer.Serialize(this, _saveOptions);
                 File.WriteAllText(configurationPath, json);
             }
             catch { }

libraries/MTConnect.NET-Common/Buffers/MTConnectAssetFileBuffer.cs

@@ -36,6 +36,15 @@ public class MTConnectAssetFileBuffer : MTConnectAssetBuffer, IDisposable
         /// </summary>
         public const string DirectoryAssets = "assets";
 
+        // Shared across every asset persistence call. See
+        // JsonFunctions.cs for the rationale — a fresh
+        // JsonSerializerOptions per call re-emits LCG DynamicMethods
+        // into the loader heap, and the GC cannot reclaim them.
+        private static readonly JsonSerializerOptions _writeOptions = new JsonSerializerOptions
+        {
+            WriteIndented = true
+        };
+
         private readonly string _basePath;
         private readonly MTConnectAssetQueue _items;
         private readonly Regex _regex = new Regex("([0-9]*)_(.*)");
@@ -432,14 +441,9 @@ private async Task<bool> WriteToFile(uint index, IAsset asset, uint originalInde
                         }
                     }
 
-                    var options = new JsonSerializerOptions
-                    {
-                        WriteIndented = true
-                    };
-
                     var assetType = Asset.GetAssetType(asset.Type);
 
-                    var json = JsonSerializer.Serialize(asset, assetType, options);
+                    var json = JsonSerializer.Serialize(asset, assetType, _writeOptions);
                     if (!string.IsNullOrEmpty(json))
                     {
                         if (UseCompression)

libraries/MTConnect.NET-Common/Clients/MTConnectClientInformation.cs

@@ -23,6 +23,15 @@ public class MTConnectClientInformation
         /// </summary>
         public const string FilenameExtension = ".json";
 
+        // Shared across every Save call. See JsonFunctions.cs for the
+        // rationale — a fresh JsonSerializerOptions per call re-emits
+        // LCG DynamicMethods into the loader heap, and the GC cannot
+        // reclaim them.
+        private static readonly JsonSerializerOptions _saveOptions = new JsonSerializerOptions
+        {
+            WriteIndented = true
+        };
+
 
         /// <summary>
         /// A token regenerated on every save, used to detect that the persisted state has changed since it was last loaded.
@@ -126,12 +135,7 @@ public void Save(string path = null)
                 var configurationPath = Path.Combine(dir, GenerateFilename(DeviceKey));
                 if (path != null) configurationPath = path;
 
-                var options = new JsonSerializerOptions
-                {
-                    WriteIndented = true
-                };
-
-                var json = JsonSerializer.Serialize(this, options);
+                var json = JsonSerializer.Serialize(this, _saveOptions);
                 File.WriteAllText(configurationPath, json);
             }
             catch { }

libraries/MTConnect.NET-Common/Configurations/AdapterApplicationConfiguration.cs

@@ -40,6 +40,15 @@ public class AdapterApplicationConfiguration : IAdapterApplicationConfiguration
         /// </summary>
         public const string DefaultYamlFilename = "adapter.config.default.yaml";
 
+        // Shared across every ReadJson call. See JsonFunctions.cs for
+        // the rationale — a fresh JsonSerializerOptions per call
+        // re-emits LCG DynamicMethods into the loader heap, and the GC
+        // cannot reclaim them.
+        private static readonly JsonSerializerOptions _readOptions = new JsonSerializerOptions()
+        {
+            ReadCommentHandling = JsonCommentHandling.Skip
+        };
+
 
         /// <summary>
         /// An opaque token regenerated each time the configuration is saved, allowing consumers to detect that the configuration has changed.
@@ -371,12 +380,7 @@ public static T ReadJson<T>(string path = null) where T : AdapterApplicationConf
                     var text = File.ReadAllText(configurationPath);
                     if (!string.IsNullOrEmpty(text))
                     {
-                        var options = new JsonSerializerOptions()
-                        {
-                            ReadCommentHandling = JsonCommentHandling.Skip
-                        };
-
-                        var configuration = JsonSerializer.Deserialize<T>(text, options);
+                        var configuration = JsonSerializer.Deserialize<T>(text, _readOptions);
                         configuration.Path = configurationPath;
                         return configuration;
                     }
@@ -411,12 +415,7 @@ public static AdapterApplicationConfiguration ReadJson(Type type, string path =
                     var text = File.ReadAllText(configurationPath);
                     if (!string.IsNullOrEmpty(text))
                     {
-                        var options = new JsonSerializerOptions()
-                        {
-                            ReadCommentHandling = JsonCommentHandling.Skip
-                        };
-
-                        var configuration = (AdapterApplicationConfiguration)JsonSerializer.Deserialize(text, type, options);
+                        var configuration = (AdapterApplicationConfiguration)JsonSerializer.Deserialize(text, type, _readOptions);
                         configuration.Path = configurationPath;
                         return configuration;
                     }

libraries/MTConnect.NET-Common/Configurations/AgentConfiguration.cs

@@ -40,6 +40,15 @@ public class AgentConfiguration : IAgentConfiguration
         /// </summary>
         public const string DefaultYamlFilename = "agent.config.default.yaml";
 
+        // Shared across every ReadJson call. See JsonFunctions.cs for
+        // the rationale — a fresh JsonSerializerOptions per call
+        // re-emits LCG DynamicMethods into the loader heap, and the GC
+        // cannot reclaim them.
+        private static readonly JsonSerializerOptions _readOptions = new JsonSerializerOptions()
+        {
+            ReadCommentHandling = JsonCommentHandling.Skip
+        };
+
 
         /// <summary>
         /// An opaque token regenerated each time the configuration is saved, allowing consumers to detect that the configuration has changed.
@@ -277,12 +286,7 @@ public static T ReadJson<T>(string path = null) where T : AgentConfiguration
                     var text = File.ReadAllText(configurationPath);
                     if (!string.IsNullOrEmpty(text))
                     {
-                        var options = new JsonSerializerOptions()
-                        {
-                            ReadCommentHandling = JsonCommentHandling.Skip
-                        };
-
-                        var configuration = JsonSerializer.Deserialize<T>(text, options);
+                        var configuration = JsonSerializer.Deserialize<T>(text, _readOptions);
                         configuration.Path = configurationPath;
                         return configuration;
                     }
@@ -317,12 +321,7 @@ public static AgentConfiguration ReadJson(Type type, string path = null)
                     var text = File.ReadAllText(configurationPath);
                     if (!string.IsNullOrEmpty(text))
                     {
-                        var options = new JsonSerializerOptions()
-                        {
-                            ReadCommentHandling = JsonCommentHandling.Skip
-                        };
-
-                        var configuration = (AgentConfiguration)JsonSerializer.Deserialize(text, type, options);
+                        var configuration = (AgentConfiguration)JsonSerializer.Deserialize(text, type, _readOptions);
                         configuration.Path = configurationPath;
                         return configuration;
                     }