C#: do not drop resource handles in finalizers (bytecodealliance#1040)

* C#: do not drop resource handles in finalizers As of this writing, we cannot safely drop a handle to an imported resource from a .NET finalizer because it may still have one or more open child resources. Once WIT has explicit syntax for indicating parent/child relationships, we should be able to use that information to keep track of child resources automatically in generated code, at which point we'll be able to drop them in the correct order from finalizers. Fixes bytecodealliance#1039 Signed-off-by: Joel Dice <[email protected]> * remove finalizers per PR feedback Signed-off-by: Joel Dice <[email protected]> --------- Signed-off-by: Joel Dice <[email protected]>
dicej · Aug 29, 2024 · c648fc7 · c648fc7
1 parent 02f0784
commit c648fc7
Showing 1 changed file with 6 additions and 6 deletions.
diff --git a/crates/csharp/src/lib.rs b/crates/csharp/src/lib.rs
@@ -1444,6 +1444,11 @@ impl InterfaceGenerator<'_> {
                     .map(|key| self.resolve.name_world_key(key))
                     .unwrap_or_else(|| "$root".into());
 
+                // As of this writing, we cannot safely drop a handle to an imported resource from a .NET finalizer
+                // because it may still have one or more open child resources.  Once WIT has explicit syntax for
+                // indicating parent/child relationships, we should be able to use that information to keep track
+                // of child resources automatically in generated code, at which point we'll be able to drop them in
+                // the correct order from finalizers.
                 uwriteln!(
                     self.src,
                     r#"
@@ -1458,22 +1463,17 @@ impl InterfaceGenerator<'_> {
 
                         public void Dispose() {{
                             Dispose(true);
-                            GC.SuppressFinalize(this);
                         }}
 
                         [DllImport("{module_name}", EntryPoint = "[resource-drop]{name}"), WasmImportLinkage]
                         private static extern void wasmImportResourceDrop(int p0);
 
                         protected virtual void Dispose(bool disposing) {{
-                            if (Handle != 0) {{
+                            if (disposing && Handle != 0) {{
                                 wasmImportResourceDrop(Handle);
                                 Handle = 0;
                             }}
                         }}
-
-                        ~{upper_camel}() {{
-                            Dispose(false);
-                        }}
                     "#
                 );
             }