GILState.Dispose is safe to be called multiple times (#1037)

lostmsu · web-flow · commit 3362cf8ce1ee · 2020-02-03T10:32:36.000+01:00
* GILState.Dispose is safe to be called multiple times
* test multiple class to GILState.Dispose
diff --git a/src/embed_tests/TestGILState.cs b/src/embed_tests/TestGILState.cs
@@ -0,0 +1,21 @@
+namespace Python.EmbeddingTest
+{
+    using NUnit.Framework;
+    using Python.Runtime;
+
+    public class TestGILState
+    {
+        /// <summary>
+        /// Ensure, that calling <see cref="Py.GILState.Dispose"/> multiple times is safe
+        /// </summary>
+        [Test]
+        public void CanDisposeMultipleTimes()
+        {
+            using (var gilState = Py.GIL())
+            {
+                for(int i = 0; i < 50; i++)
+                    gilState.Dispose();
+            }
+        }
+    }
+}
diff --git a/src/runtime/pythonengine.cs b/src/runtime/pythonengine.cs
@@ -643,7 +643,8 @@ public static PyScope CreateScope(string name)
         
         public class GILState : IDisposable
         {
-            private IntPtr state;
+            private readonly IntPtr state;
+            private bool isDisposed;
 
             internal GILState()
             {
@@ -652,8 +653,11 @@ internal GILState()
 
             public void Dispose()
             {
+                if (this.isDisposed) return;
+
                 PythonEngine.ReleaseLock(state);
                 GC.SuppressFinalize(this);
+                this.isDisposed = true;
             }
 
             ~GILState()

Original file line number	Diff line number	Diff line change
`@@ -643,7 +643,8 @@ public static PyScope CreateScope(string name)`
`643`	`643`
`644`	`644`	`public class GILState : IDisposable`
`645`	`645`	`{`
`646`		`- private IntPtr state;`
	`646`	`+ private readonly IntPtr state;`
	`647`	`+ private bool isDisposed;`
`647`	`648`
`648`	`649`	`internal GILState()`
`649`	`650`	`{`
`@@ -652,8 +653,11 @@ internal GILState()`
`652`	`653`
`653`	`654`	`public void Dispose()`
`654`	`655`	`{`
	`656`	`+ if (this.isDisposed) return;`
	`657`	`+`
`655`	`658`	`PythonEngine.ReleaseLock(state);`
`656`	`659`	`GC.SuppressFinalize(this);`
	`660`	`+ this.isDisposed = true;`
`657`	`661`	`}`
`658`	`662`
`659`	`663`	`~GILState()`