1 files changed, 92 insertions, 0 deletions
diff --git a/js/src/jit-test/tests/structured-clone/tenuring.js b/js/src/jit-test/tests/structured-clone/tenuring.js
new file mode 100644
index 0000000000..0fffa064fa
--- /dev/null
+++ b/js/src/jit-test/tests/structured-clone/tenuring.js
@@ -0,0 +1,92 @@
+// Check that we switch to allocating in the tenure heap after the first
+// nursery collection.
+
+function buildObjectTree(depth) {
+  if (depth === 0) {
+    return "leaf";
+  }
+
+  return {
+    left: buildObjectTree(depth - 1),
+    right: buildObjectTree(depth - 1)
+  };
+}
+
+function buildArrayTree(depth) {
+  if (depth === 0) {
+    return [];
+  }
+
+  return [
+    buildArrayTree(depth - 1),
+    buildArrayTree(depth - 1)
+  ];
+}
+
+function testRoundTrip(depth, objectTree, expectedNurseryAllocated) {
+  const input = objectTree ? buildObjectTree(depth) : buildArrayTree(depth);
+
+  gc();
+  const initialMinorNumber = gcparam('minorGCNumber');
+
+  const output = deserialize(serialize(input));
+  checkHeap(output, depth, objectTree, expectedNurseryAllocated);
+
+  const minorCollections = gcparam('minorGCNumber') - initialMinorNumber;
+  const expectedMinorCollections = expectedNurseryAllocated ? 0 : 1;
+  assertEq(minorCollections, expectedMinorCollections);
+}
+
+function checkHeap(tree, depth, objectTree, expectedNurseryAllocated) {
+  const counts = countHeapLocations(tree, objectTree);
+
+  const total = counts.nursery + counts.tenured;
+  assertEq(total, (2 ** (depth + 1)) - 1);
+
+  if (expectedNurseryAllocated) {
+    assertEq(counts.tenured, 0);
+    assertEq(counts.nursery >= 1, true);
+  } else {
+    assertEq(counts.tenured >= 1, true);
+    // We get a single nursery allocation when we trigger minor GC.
+    assertEq(counts.nursery <= 1, true);
+  }
+}
+
+function countHeapLocations(tree, objectTree, counts) {
+  if (!counts) {
+    counts = {nursery: 0, tenured: 0};
+  }
+
+  if (isNurseryAllocated(tree)) {
+    counts.nursery++;
+  } else {
+    counts.tenured++;
+  }
+
+  if (objectTree) {
+    if (tree !== "leaf") {
+      countHeapLocations(tree.left, objectTree, counts);
+      countHeapLocations(tree.right, objectTree, counts);
+    }
+  } else {
+    if (tree.length !== 0) {
+      countHeapLocations(tree[0], objectTree, counts);
+      countHeapLocations(tree[1], objectTree, counts);
+    }
+  }
+
+  return counts;
+}
+
+gczeal(0);
+gcparam('minNurseryBytes', 1024 * 1024);
+gcparam('maxNurseryBytes', 1024 * 1024);
+gc();
+
+testRoundTrip(1, true, true);
+testRoundTrip(1, false, true);
+testRoundTrip(4, true, true);
+testRoundTrip(4, false, true);
+testRoundTrip(15, true, false);
+testRoundTrip(15, false, false);