1 files changed, 40 insertions, 0 deletions
diff --git a/js/src/devtools/gc-ubench/benchmarks/deepWeakMap.js b/js/src/devtools/gc-ubench/benchmarks/deepWeakMap.js
new file mode 100644
index 0000000000..bf46d1d97b
--- /dev/null
+++ b/js/src/devtools/gc-ubench/benchmarks/deepWeakMap.js
@@ -0,0 +1,40 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this file,
+ * You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+tests.set(
+  "deepWeakMap",
+  (function() {
+    var garbage = [];
+    var garbageIndex = 0;
+    return {
+      description: "o={wm,k}; w.mk[k]=o2={wm2,k2}; wm2[k2]=....",
+
+      defaultGarbagePerFrame: "1K",
+      defaultGarbagePiles: "1K",
+
+      load: N => {
+        garbage = new Array(N);
+      },
+
+      unload: () => {
+        garbage = [];
+        garbageIndex = 0;
+      },
+
+      makeGarbage: M => {
+        var initial = {};
+        var prev = initial;
+        for (var i = 0; i < M; i++) {
+          var obj = [new WeakMap(), Object.create(null)];
+          obj[0].set(obj[1], prev);
+          prev = obj;
+        }
+        garbage[garbageIndex++] = initial;
+        if (garbageIndex == garbage.length) {
+          garbageIndex = 0;
+        }
+      },
+    };
+  })()
+);