Ensure use of correct env in JSReference (microsoft#120)

Author: jasongin

.vscode/tasks.json

@@ -46,7 +46,10 @@
                 "-c",
                 "Release",
                 "-f",
-                "net7.0"
+                "net7.0",
+                "--",
+                "--filter",
+                "*.NonAot.*"
             ],
             "options": {
                 "cwd": "${workspaceFolder}/bench"
@@ -55,6 +58,28 @@
                 "reveal": "always"
             },
             "problemMatcher": "$msCompile"
-        }
-    ]
+        },
+        {
+          "label": "bench AOT",
+          "command": "dotnet",
+          "type": "shell",
+          "args": [
+              "run",
+              "-c",
+              "Release",
+              "-f",
+              "net7.0",
+              "--",
+              "--filter",
+              "*.Aot.*"
+          ],
+          "options": {
+              "cwd": "${workspaceFolder}/bench"
+          },
+          "presentation": {
+              "reveal": "always"
+          },
+          "problemMatcher": "$msCompile"
+      }
+  ]
 }

bench/Benchmarks.cs

@@ -4,6 +4,7 @@
 using System;
 using System.IO;
 using BenchmarkDotNet.Attributes;
+using BenchmarkDotNet.Configs;
 using BenchmarkDotNet.Jobs;
 using BenchmarkDotNet.Running;
 using Microsoft.JavaScript.NodeApi.Runtimes;
@@ -18,7 +19,8 @@ public static void Main(string[] args)
     {
         // Example: dotnet run -c Release --filter aot
         // If no filter is specified, the switcher will prompt.
-        BenchmarkSwitcher.FromAssembly(typeof(Benchmarks).Assembly).Run(args);
+        BenchmarkSwitcher.FromAssembly(typeof(Benchmarks).Assembly).Run(args,
+            ManualConfig.Create(DefaultConfig.Instance).WithOptions(ConfigOptions.JoinSummary));
     }
 
     public class NonAot : Benchmarks
@@ -41,6 +43,7 @@ public class Aot : Benchmarks
     private napi_env _env;
     private JSValue _function;
     private JSValue _callback;
+    private JSReference _reference = null!;
 
     [GlobalSetup]
     public void Setup()
@@ -56,14 +59,28 @@ public void Setup()
         JSValueScope scope = new(JSValueScopeType.Root, _env);
 
         // Create some JS values that will be used by the benchmarks.
+
         _function = JSNativeApi.RunScript("function callMeBack(cb) { cb(); }; callMeBack");
         _callback = JSValue.CreateFunction("callback", (args) => JSValue.Undefined);
+
+        _reference = new JSReference(_function);
     }
 
     [Benchmark]
     public void CallJS()
     {
         _function.Call(thisArg: default, _callback);
     }
-}
 
+    [Benchmark]
+    public void GetReference()
+    {
+        _ = _reference.GetValue()!.Value;
+    }
+
+    [Benchmark]
+    public void CreateAndDiposeReference()
+    {
+        using JSReference reference = new(_function);
+    }
+}

src/NodeApi/JSReference.cs

@@ -23,8 +23,9 @@ namespace Microsoft.JavaScript.NodeApi;
 /// </remarks>
 public class JSReference : IDisposable
 {
-    private readonly JSRuntimeContext? _context;
     private readonly napi_ref _handle;
+    private readonly napi_env _env;
+    private readonly JSRuntimeContext? _context;
 
     public bool IsWeak { get; private set; }
 
@@ -40,8 +41,9 @@ public JSReference(JSValue value, bool isWeak = false)
 
     public JSReference(napi_ref handle, bool isWeak = false)
     {
-        _context = JSRuntimeContext.Current;
         _handle = handle;
+        _env = (napi_env)JSValueScope.Current;
+        _context = JSRuntimeContext.Current;
         IsWeak = isWeak;
     }
 
@@ -68,7 +70,7 @@ public void MakeWeak()
         ThrowIfDisposed();
         if (!IsWeak)
         {
-            napi_reference_unref((napi_env)JSValueScope.Current, _handle, default).ThrowIfFailed();
+            napi_reference_unref(_env, _handle, default).ThrowIfFailed();
             IsWeak = true;
         }
     }
@@ -77,16 +79,15 @@ public void MakeStrong()
         ThrowIfDisposed();
         if (IsWeak)
         {
-            napi_reference_ref((napi_env)JSValueScope.Current, _handle, default).ThrowIfFailed();
+            napi_reference_ref(_env, _handle, default).ThrowIfFailed();
             IsWeak = true;
         }
     }
 
     public JSValue? GetValue()
     {
         ThrowIfDisposed();
-        napi_get_reference_value(
-            (napi_env)JSValueScope.Current, _handle, out napi_value result).ThrowIfFailed();
+        napi_get_reference_value(_env, _handle, out napi_value result).ThrowIfFailed();
         return result;
     }
 
@@ -123,13 +124,12 @@ protected virtual void Dispose(bool disposing)
             // as the native host. In that case the reference must be disposed from the JS thread.
             if (_context == null)
             {
-                napi_delete_reference((napi_env)JSValueScope.Current, handle).ThrowIfFailed();
+                napi_delete_reference(_env, handle).ThrowIfFailed();
             }
             else
             {
-                _context?.SynchronizationContext.Post(
-                    () => napi_delete_reference((napi_env)_context, handle).ThrowIfFailed(),
-                    allowSync: true);
+                _context.SynchronizationContext.Post(
+                    () => napi_delete_reference(_env, handle).ThrowIfFailed(), allowSync: true);
             }
         }
     }