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/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 4 -*-
*/
/* 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 "mozilla/TypeTraits.h"
#include "mozilla/UniquePtr.h"
#include "js/RootingAPI.h"
#include "jsapi-tests/tests.h"
#include "vm/Runtime.h"
template <typename T>
static T* CreateGCThing(JSContext* cx)
{
MOZ_CRASH();
return nullptr;
}
template <>
JSObject* CreateGCThing(JSContext* cx)
{
JS::RootedObject obj(cx, JS_NewPlainObject(cx));
if (!obj)
return nullptr;
JS_DefineProperty(cx, obj, "x", 42, 0);
return obj;
}
template <>
JSFunction* CreateGCThing(JSContext* cx)
{
/*
* We don't actually use the function as a function, so here we cheat and
* cast a JSObject.
*/
return static_cast<JSFunction*>(CreateGCThing<JSObject>(cx));
}
BEGIN_TEST(testGCHeapPostBarriers)
{
/* Sanity check - objects start in the nursery and then become tenured. */
JS_GC(cx);
JS::RootedObject obj(cx, CreateGCThing<JSObject>(cx));
CHECK(js::gc::IsInsideNursery(obj.get()));
JS_GC(cx);
CHECK(!js::gc::IsInsideNursery(obj.get()));
JS::RootedObject tenuredObject(cx, obj);
/* Currently JSObject and JSFunction objects are nursery allocated. */
CHECK(TestHeapPostBarriersForType<JSObject>());
CHECK(TestHeapPostBarriersForType<JSFunction>());
return true;
}
bool
CanAccessObject(JSObject* obj)
{
JS::RootedObject rootedObj(cx, obj);
JS::RootedValue value(cx);
CHECK(JS_GetProperty(cx, rootedObj, "x", &value));
CHECK(value.isInt32());
CHECK(value.toInt32() == 42);
return true;
}
template <typename T>
bool
TestHeapPostBarriersForType()
{
CHECK((TestHeapPostBarriersForWrapper<T, JS::Heap<T*>>()));
CHECK((TestHeapPostBarriersForWrapper<T, js::GCPtr<T*>>()));
CHECK((TestHeapPostBarriersForWrapper<T, js::HeapPtr<T*>>()));
return true;
}
template <typename T, typename W>
bool
TestHeapPostBarriersForWrapper()
{
CHECK((TestHeapPostBarrierUpdate<T, W>()));
CHECK((TestHeapPostBarrierInitFailure<T, W>()));
return true;
}
template <typename T, typename W>
bool
TestHeapPostBarrierUpdate()
{
// Normal case - allocate a heap object, write a nursery pointer into it and
// check that it gets updated on minor GC.
T* initialObj = CreateGCThing<T>(cx);
CHECK(initialObj != nullptr);
CHECK(js::gc::IsInsideNursery(initialObj));
uintptr_t initialObjAsInt = uintptr_t(initialObj);
W* ptr = nullptr;
{
auto heapPtr = cx->make_unique<W>();
CHECK(heapPtr);
W& wrapper = *heapPtr;
CHECK(wrapper.get() == nullptr);
wrapper = initialObj;
CHECK(wrapper == initialObj);
ptr = heapPtr.release();
}
cx->minorGC(JS::gcreason::API);
CHECK(uintptr_t(ptr->get()) != initialObjAsInt);
CHECK(!js::gc::IsInsideNursery(ptr->get()));
CHECK(CanAccessObject(ptr->get()));
return true;
}
template <typename T, typename W>
bool
TestHeapPostBarrierInitFailure()
{
// Failure case - allocate a heap object, write a nursery pointer into it
// and fail to complete initialization.
T* initialObj = CreateGCThing<T>(cx);
CHECK(initialObj != nullptr);
CHECK(js::gc::IsInsideNursery(initialObj));
{
auto heapPtr = cx->make_unique<W>();
CHECK(heapPtr);
W& wrapper = *heapPtr;
CHECK(wrapper.get() == nullptr);
wrapper = initialObj;
CHECK(wrapper == initialObj);
}
cx->minorGC(JS::gcreason::API);
return true;
}
END_TEST(testGCHeapPostBarriers)
BEGIN_TEST(testUnbarrieredEquality)
{
// Use ArrayBuffers because they have finalizers, which allows using them
// in ObjectPtr without awkward conversations about nursery allocatability.
JS::RootedObject robj(cx, JS_NewArrayBuffer(cx, 20));
JS::RootedObject robj2(cx, JS_NewArrayBuffer(cx, 30));
cx->gc.evictNursery(); // Need tenured objects
// Need some bare pointers to compare against.
JSObject* obj = robj;
JSObject* obj2 = robj2;
const JSObject* constobj = robj;
const JSObject* constobj2 = robj2;
// Make them gray. We will make sure they stay gray. (For most reads, the
// barrier will unmark gray.)
using namespace js::gc;
TenuredCell* cell = &obj->asTenured();
TenuredCell* cell2 = &obj2->asTenured();
cell->markIfUnmarked(GRAY);
cell2->markIfUnmarked(GRAY);
MOZ_ASSERT(cell->isMarked(GRAY));
MOZ_ASSERT(cell2->isMarked(GRAY));
{
JS::Heap<JSObject*> heap(obj);
JS::Heap<JSObject*> heap2(obj2);
CHECK(TestWrapper(obj, obj2, heap, heap2));
CHECK(TestWrapper(constobj, constobj2, heap, heap2));
}
{
JS::TenuredHeap<JSObject*> heap(obj);
JS::TenuredHeap<JSObject*> heap2(obj2);
CHECK(TestWrapper(obj, obj2, heap, heap2));
CHECK(TestWrapper(constobj, constobj2, heap, heap2));
}
{
JS::ObjectPtr objptr(obj);
JS::ObjectPtr objptr2(obj2);
CHECK(TestWrapper(obj, obj2, objptr, objptr2));
CHECK(TestWrapper(constobj, constobj2, objptr, objptr2));
objptr.finalize(cx);
objptr2.finalize(cx);
}
// Sanity check that the barriers normally mark things black.
{
JS::Heap<JSObject*> heap(obj);
JS::Heap<JSObject*> heap2(obj2);
heap.get();
heap2.get();
CHECK(cell->isMarked(BLACK));
CHECK(cell2->isMarked(BLACK));
}
return true;
}
template <typename ObjectT, typename WrapperT>
bool
TestWrapper(ObjectT obj, ObjectT obj2, WrapperT& wrapper, WrapperT& wrapper2)
{
using namespace js::gc;
const TenuredCell& cell = obj->asTenured();
const TenuredCell& cell2 = obj2->asTenured();
int x = 0;
CHECK(cell.isMarked(GRAY));
CHECK(cell2.isMarked(GRAY));
x += obj == obj2;
CHECK(cell.isMarked(GRAY));
CHECK(cell2.isMarked(GRAY));
x += obj == wrapper2;
CHECK(cell.isMarked(GRAY));
CHECK(cell2.isMarked(GRAY));
x += wrapper == obj2;
CHECK(cell.isMarked(GRAY));
CHECK(cell2.isMarked(GRAY));
x += wrapper == wrapper2;
CHECK(cell.isMarked(GRAY));
CHECK(cell2.isMarked(GRAY));
CHECK(x == 0);
x += obj != obj2;
CHECK(cell.isMarked(GRAY));
CHECK(cell2.isMarked(GRAY));
x += obj != wrapper2;
CHECK(cell.isMarked(GRAY));
CHECK(cell2.isMarked(GRAY));
x += wrapper != obj2;
CHECK(cell.isMarked(GRAY));
CHECK(cell2.isMarked(GRAY));
x += wrapper != wrapper2;
CHECK(cell.isMarked(GRAY));
CHECK(cell2.isMarked(GRAY));
CHECK(x == 4);
return true;
}
END_TEST(testUnbarrieredEquality)
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