The Tor Browser: js/src/jsapi-tests/testGCHeapPostBarriers.cpp@b8a032363ba2

Incorporate requested changes from Mozilla in review:
https://bugzilla.mozilla.org/show_bug.cgi?id=1123480#c6

     1 /* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 4 -*-

     2 * vim: set ts=8 sts=4 et sw=4 tw=99:

     3 */

     4 /* This Source Code Form is subject to the terms of the Mozilla Public

     5  * License, v. 2.0. If a copy of the MPL was not distributed with this

     6  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */

     8 #ifdef JSGC_GENERATIONAL

    10 #include "js/RootingAPI.h"

    11 #include "jsapi-tests/tests.h"

    13 BEGIN_TEST(testGCHeapPostBarriers)

    14 {

    15     /* Sanity check - objects start in the nursery and then become tenured. */

    16     JS_GC(cx->runtime());

    17     JS::RootedObject obj(cx, NurseryObject());

    18     CHECK(js::gc::IsInsideNursery(obj.get()));

    19     JS_GC(cx->runtime());

    20     CHECK(!js::gc::IsInsideNursery(obj.get()));

    21     JS::RootedObject tenuredObject(cx, obj);

    23     /* Currently JSObject and JSFunction objects are nursery allocated. */

    24     CHECK(TestHeapPostBarriers(NurseryObject()));

    25     CHECK(TestHeapPostBarriers(NurseryFunction()));

    27     return true;

    28 }

    30 template <typename T>

    31 bool

    32 TestHeapPostBarriers(T initialObj)

    33 {

    34     CHECK(initialObj != nullptr);

    35     CHECK(js::gc::IsInsideNursery(initialObj));

    37     /* Construct Heap<> wrapper. */

    38     JS::Heap<T> *heapData = new JS::Heap<T>();

    39     CHECK(heapData);

    40     CHECK(heapData->get() == nullptr);

    41     heapData->set(initialObj);

    43     /* Store the pointer as an integer so that the hazard analysis will miss it. */

    44     uintptr_t initialObjAsInt = uintptr_t(initialObj);

    46     /* Perform minor GC and check heap wrapper is udated with new pointer. */

    47     js::MinorGC(cx, JS::gcreason::API);

    48     CHECK(uintptr_t(heapData->get()) != initialObjAsInt);

    49     CHECK(!js::gc::IsInsideNursery(heapData->get()));

    51     /* Check object is definitely still alive. */

    52     JS::Rooted<T> obj(cx, heapData->get());

    53     JS::RootedValue value(cx);

    54     CHECK(JS_GetProperty(cx, obj, "x", &value));

    55     CHECK(value.isInt32());

    56     CHECK(value.toInt32() == 42);

    58     delete heapData;

    59     return true;

    60 }

    62 JSObject *NurseryObject()

    63 {

    64     JS::RootedObject obj(cx, JS_NewObject(cx, nullptr, JS::NullPtr(), JS::NullPtr()));

    65     if (!obj)

    66         return nullptr;

    67     JS_DefineProperty(cx, obj, "x", 42, 0);

    68     return obj;

    69 }

    71 JSFunction *NurseryFunction()

    72 {

    73     /*

    74      * We don't actually use the function as a function, so here we cheat and

    75      * cast a JSObject.

    76      */

    77     return static_cast<JSFunction *>(NurseryObject());

    78 }

    80 END_TEST(testGCHeapPostBarriers)

    82 #endif

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