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/* -*- 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/. */
/*
* Tests that generational garbage collection post-barriers are correctly
* implemented for nsTArrays that contain JavaScript Values.
*/
#include "mozilla/UniquePtr.h"
#include "jsapi.h"
#include "nsTArray.h"
#include "gtest/gtest.h"
#include "js/PropertyAndElement.h" // JS_GetProperty, JS_SetProperty
#include "js/TracingAPI.h"
#include "js/HeapAPI.h"
#include "mozilla/CycleCollectedJSContext.h"
using namespace mozilla;
template <class ArrayT>
static void TraceArray(JSTracer* trc, void* data) {
ArrayT* array = static_cast<ArrayT*>(data);
for (unsigned i = 0; i < array->Length(); ++i) {
JS::TraceEdge(trc, &array->ElementAt(i), "array-element");
}
}
/*
* Use arrays with initial size much smaller than the final number of elements
* to test that moving Heap<T> elements works correctly.
*/
const size_t ElementCount = 100;
const size_t InitialElements = ElementCount / 10;
template <class ArrayT>
static void TestGrow(JSContext* cx) {
JS_GC(cx);
auto array = MakeUnique<ArrayT>();
ASSERT_TRUE(array != nullptr);
JS_AddExtraGCRootsTracer(cx, TraceArray<ArrayT>, array.get());
/*
* Create the array and fill it with new JS objects. With GGC these will be
* allocated in the nursery.
*/
JS::RootedValue value(cx);
const char* property = "foo";
for (size_t i = 0; i < ElementCount; ++i) {
JS::RootedObject obj(cx, JS_NewPlainObject(cx));
ASSERT_FALSE(JS::ObjectIsTenured(obj));
value = JS::Int32Value(static_cast<int32_t>(i));
ASSERT_TRUE(JS_SetProperty(cx, obj, property, value));
ASSERT_TRUE(array->AppendElement(obj, fallible));
}
/*
* If postbarriers are not working, we will crash here when we try to mark
* objects that have been moved to the tenured heap.
*/
JS_GC(cx);
/*
* Sanity check that our array contains what we expect.
*/
ASSERT_EQ(array->Length(), ElementCount);
for (size_t i = 0; i < array->Length(); i++) {
JS::RootedObject obj(cx, array->ElementAt(i));
ASSERT_TRUE(JS::ObjectIsTenured(obj));
ASSERT_TRUE(JS_GetProperty(cx, obj, property, &value));
ASSERT_TRUE(value.isInt32());
ASSERT_EQ(static_cast<int32_t>(i), value.toInt32());
}
JS_RemoveExtraGCRootsTracer(cx, TraceArray<ArrayT>, array.get());
}
template <class ArrayT>
static void TestShrink(JSContext* cx) {
JS_GC(cx);
auto array = MakeUnique<ArrayT>();
ASSERT_TRUE(array != nullptr);
JS_AddExtraGCRootsTracer(cx, TraceArray<ArrayT>, array.get());
/*
* Create the array and fill it with new JS objects. With GGC these will be
* allocated in the nursery.
*/
JS::RootedValue value(cx);
const char* property = "foo";
for (size_t i = 0; i < ElementCount; ++i) {
JS::RootedObject obj(cx, JS_NewPlainObject(cx));
ASSERT_FALSE(JS::ObjectIsTenured(obj));
value = JS::Int32Value(static_cast<int32_t>(i));
ASSERT_TRUE(JS_SetProperty(cx, obj, property, value));
ASSERT_TRUE(array->AppendElement(obj, fallible));
}
/* Shrink and compact the array */
array->RemoveElementsAt(InitialElements, ElementCount - InitialElements);
array->Compact();
JS_GC(cx);
ASSERT_EQ(array->Length(), InitialElements);
for (size_t i = 0; i < array->Length(); i++) {
JS::RootedObject obj(cx, array->ElementAt(i));
ASSERT_TRUE(JS::ObjectIsTenured(obj));
ASSERT_TRUE(JS_GetProperty(cx, obj, property, &value));
ASSERT_TRUE(value.isInt32());
ASSERT_EQ(static_cast<int32_t>(i), value.toInt32());
}
JS_RemoveExtraGCRootsTracer(cx, TraceArray<ArrayT>, array.get());
}
template <class ArrayT>
static void TestArrayType(JSContext* cx) {
TestGrow<ArrayT>(cx);
TestShrink<ArrayT>(cx);
}
static void CreateGlobalAndRunTest(JSContext* cx) {
static const JSClass GlobalClass = {"global", JSCLASS_GLOBAL_FLAGS,
&JS::DefaultGlobalClassOps};
JS::RealmOptions options;
// dummy
options.behaviors().setReduceTimerPrecisionCallerType(
JS::RTPCallerTypeToken{0});
JS::PersistentRootedObject global(cx);
global = JS_NewGlobalObject(cx, &GlobalClass, nullptr,
JS::FireOnNewGlobalHook, options);
ASSERT_TRUE(global != nullptr);
JS::Realm* oldRealm = JS::EnterRealm(cx, global);
using ElementT = JS::Heap<JSObject*>;
TestArrayType<nsTArray<ElementT>>(cx);
TestArrayType<FallibleTArray<ElementT>>(cx);
TestArrayType<AutoTArray<ElementT, 1>>(cx);
JS::LeaveRealm(cx, oldRealm);
}
TEST(GCPostBarriers, nsTArray)
{
CycleCollectedJSContext* ccjscx = CycleCollectedJSContext::Get();
ASSERT_TRUE(ccjscx != nullptr);
JSContext* cx = ccjscx->Context();
ASSERT_TRUE(cx != nullptr);
CreateGlobalAndRunTest(cx);
}
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