[Web] Retain evicted shape tuples until teardown

web/src/cache_state.ts

@@ -145,11 +145,18 @@ export class CacheState {
    * Invalidation rule: None required — shape tuples are immutable.
    */
   readonly shapeCache: LRUCache<string, Disposable>;
+  /**
+   * Shape tuples evicted from the LRU cache but retained until instance teardown.
+   *
+   * `makeShapeTuple()` returns borrowed references, so an evicted tuple can still
+   * be in use by a pending GPU dispatch.
+   */
+  private readonly evictedShapeTuples = new Set<Disposable>();
 
   constructor(shapeCacheSize: number = 256) {
     this.shapeCache = new LRUCache<string, Disposable>(
       shapeCacheSize,
-      (_key, value) => value.dispose()
+      (_key, value) => this.evictedShapeTuples.add(value)
     );
   }
 
@@ -168,8 +175,12 @@ export class CacheState {
    */
   dispose(): void {
     for (const obj of this.shapeCache.values()) {
-      obj.dispose();
+      this.evictedShapeTuples.add(obj);
     }
     this.shapeCache.invalidate();
+    for (const obj of this.evictedShapeTuples) {
+      obj.dispose();
+    }
+    this.evictedShapeTuples.clear();
   }
 }

web/tests/node/test_cache_state.js

@@ -0,0 +1,35 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License.  You may obtain a copy of the License at
+ *
+ *   http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied.  See the License for the
+ * specific language governing permissions and limitations
+ * under the License.
+ */
+const { CacheState } = require("../../src/cache_state.ts");
+
+test("keeps an evicted shape tuple alive until cache state disposal", () => {
+  const cacheState = new CacheState(1);
+  const first = { dispose: jest.fn() };
+  const second = { dispose: jest.fn() };
+
+  cacheState.shapeCache.get("first", () => first);
+  cacheState.shapeCache.get("second", () => second);
+
+  expect(first.dispose).not.toHaveBeenCalled();
+
+  cacheState.dispose();
+
+  expect(first.dispose).toHaveBeenCalledTimes(1);
+  expect(second.dispose).toHaveBeenCalledTimes(1);
+});