summaryrefslogtreecommitdiffstats
path: root/js/src/jsapi-tests/testGCUniqueId.cpp
diff options
context:
space:
mode:
Diffstat (limited to 'js/src/jsapi-tests/testGCUniqueId.cpp')
-rw-r--r--js/src/jsapi-tests/testGCUniqueId.cpp125
1 files changed, 125 insertions, 0 deletions
diff --git a/js/src/jsapi-tests/testGCUniqueId.cpp b/js/src/jsapi-tests/testGCUniqueId.cpp
new file mode 100644
index 0000000000..1c5652f280
--- /dev/null
+++ b/js/src/jsapi-tests/testGCUniqueId.cpp
@@ -0,0 +1,125 @@
+/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*-
+ * vim: set ts=8 sts=2 et sw=2 tw=80:
+ */
+/* 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/. */
+
+#include "js/GCVector.h"
+
+#include "jsapi-tests/tests.h"
+
+#include "gc/StableCellHasher-inl.h"
+
+using namespace js;
+
+static void MinimizeHeap(JSContext* cx) {
+ // The second collection is to force us to wait for the background
+ // sweeping that the first GC started to finish.
+ JS_GC(cx);
+ JS_GC(cx);
+ js::gc::FinishGC(cx);
+}
+
+BEGIN_TEST(testGCUID) {
+ AutoLeaveZeal nozeal(cx);
+
+ uint64_t uid = 0;
+ uint64_t tmp = 0;
+
+ // Ensure the heap is as minimal as it can get.
+ MinimizeHeap(cx);
+
+ JS::RootedObject obj(cx, JS_NewPlainObject(cx));
+ uintptr_t nurseryAddr = uintptr_t(obj.get());
+ CHECK(obj);
+ CHECK(gc::IsInsideNursery(obj));
+
+ // Do not start with an ID.
+ CHECK(!gc::HasUniqueId(obj));
+
+ // Ensure we can get a new UID.
+ CHECK(gc::GetOrCreateUniqueId(obj, &uid));
+ CHECK(uid > gc::LargestTaggedNullCellPointer);
+
+ // We should now have an id.
+ CHECK(gc::HasUniqueId(obj));
+
+ // Calling again should get us the same thing.
+ CHECK(gc::GetOrCreateUniqueId(obj, &tmp));
+ CHECK(uid == tmp);
+
+ // Tenure the thing and check that the UID moved with it.
+ MinimizeHeap(cx);
+ uintptr_t tenuredAddr = uintptr_t(obj.get());
+ CHECK(tenuredAddr != nurseryAddr);
+ CHECK(!gc::IsInsideNursery(obj));
+ CHECK(gc::HasUniqueId(obj));
+ CHECK(gc::GetOrCreateUniqueId(obj, &tmp));
+ CHECK(uid == tmp);
+
+ // Allocate a new nursery thing in the same location and check that we
+ // removed the prior uid that was attached to the location.
+ obj = JS_NewPlainObject(cx);
+ CHECK(obj);
+ CHECK(uintptr_t(obj.get()) == nurseryAddr);
+ CHECK(!gc::HasUniqueId(obj));
+
+ // Try to get another tenured object in the same location and check that
+ // the uid was removed correctly.
+ obj = nullptr;
+ MinimizeHeap(cx);
+ obj = JS_NewPlainObject(cx);
+ MinimizeHeap(cx);
+ CHECK(uintptr_t(obj.get()) == tenuredAddr);
+ CHECK(!gc::HasUniqueId(obj));
+ CHECK(gc::GetOrCreateUniqueId(obj, &tmp));
+ CHECK(uid != tmp);
+ uid = tmp;
+
+ // Allocate a few arenas worth of objects to ensure we get some compaction.
+ const static size_t N = 2049;
+ using ObjectVector = JS::GCVector<JSObject*>;
+ JS::Rooted<ObjectVector> vec(cx, ObjectVector(cx));
+ for (size_t i = 0; i < N; ++i) {
+ obj = JS_NewPlainObject(cx);
+ CHECK(obj);
+ CHECK(vec.append(obj));
+ }
+
+ // Transfer our vector to tenured if it isn't there already.
+ MinimizeHeap(cx);
+
+ // Tear holes in the heap by unrooting the even objects and collecting.
+ JS::Rooted<ObjectVector> vec2(cx, ObjectVector(cx));
+ for (size_t i = 0; i < N; ++i) {
+ if (i % 2 == 1) {
+ CHECK(vec2.append(vec[i]));
+ }
+ }
+ vec.clear();
+
+ // Grab the last object in the vector as our object of interest.
+ obj = vec2.back();
+ CHECK(obj);
+ CHECK(!gc::IsInsideNursery(obj));
+ tenuredAddr = uintptr_t(obj.get());
+ CHECK(gc::GetOrCreateUniqueId(obj, &uid));
+
+ // Force a compaction to move the object and check that the uid moved to
+ // the new tenured heap location.
+ JS::PrepareForFullGC(cx);
+ JS::NonIncrementalGC(cx, JS::GCOptions::Shrink, JS::GCReason::API);
+
+ // There's a very low probability that this check could fail, but it is
+ // possible. If it becomes an annoying intermittent then we should make
+ // this test more robust by recording IDs of many objects and then checking
+ // that some have moved.
+ CHECK(uintptr_t(obj.get()) != tenuredAddr);
+ CHECK(gc::HasUniqueId(obj));
+ CHECK(gc::GetOrCreateUniqueId(obj, &tmp));
+ CHECK(uid == tmp);
+
+ return true;
+}
+END_TEST(testGCUID)