path: root/js/src/jsapi-tests/testWeakMap.cpp

/* -*- 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 "jscompartment.h"

#include "gc/Zone.h"

#include "jsapi-tests/tests.h"

JSObject* keyDelegate = nullptr;

BEGIN_TEST(testWeakMap_basicOperations)
{
    JS::RootedObject map(cx, JS::NewWeakMapObject(cx));
    CHECK(IsWeakMapObject(map));

    JS::RootedObject key(cx, newKey());
    CHECK(key);
    CHECK(!IsWeakMapObject(key));

    JS::RootedValue r(cx);
    CHECK(GetWeakMapEntry(cx, map, key, &r));
    CHECK(r.isUndefined());

    CHECK(checkSize(map, 0));

    JS::RootedValue val(cx, JS::Int32Value(1));
    CHECK(SetWeakMapEntry(cx, map, key, val));

    CHECK(GetWeakMapEntry(cx, map, key, &r));
    CHECK(r == val);
    CHECK(checkSize(map, 1));

    JS_GC(cx);

    CHECK(GetWeakMapEntry(cx, map, key, &r));
    CHECK(r == val);
    CHECK(checkSize(map, 1));

    key = nullptr;
    JS_GC(cx);

    CHECK(checkSize(map, 0));

    return true;
}

JSObject* newKey()
{
    return JS_NewPlainObject(cx);
}

bool
checkSize(JS::HandleObject map, uint32_t expected)
{
    JS::RootedObject keys(cx);
    CHECK(JS_NondeterministicGetWeakMapKeys(cx, map, &keys));

    uint32_t length;
    CHECK(JS_GetArrayLength(cx, keys, &length));
    CHECK(length == expected);

    return true;
}
END_TEST(testWeakMap_basicOperations)

BEGIN_TEST(testWeakMap_keyDelegates)
{
    JS_SetGCParameter(cx, JSGC_MODE, JSGC_MODE_INCREMENTAL);
    JS_GC(cx);
    JS::RootedObject map(cx, JS::NewWeakMapObject(cx));
    CHECK(map);

    JS::RootedObject key(cx, newKey());
    CHECK(key);

    JS::RootedObject delegate(cx, newDelegate());
    CHECK(delegate);
    keyDelegate = delegate;

    JS::RootedObject delegateRoot(cx);
    {
        JSAutoCompartment ac(cx, delegate);
        delegateRoot = JS_NewPlainObject(cx);
        CHECK(delegateRoot);
        JS::RootedValue delegateValue(cx, JS::ObjectValue(*delegate));
        CHECK(JS_DefineProperty(cx, delegateRoot, "delegate", delegateValue, 0));
    }
    delegate = nullptr;

    /*
     * Perform an incremental GC, introducing an unmarked CCW to force the map
     * zone to finish marking before the delegate zone.
     */
    CHECK(newCCW(map, delegateRoot));
    js::SliceBudget budget(js::WorkBudget(1000000));
    cx->gc.startDebugGC(GC_NORMAL, budget);
    while (JS::IsIncrementalGCInProgress(cx))
        cx->gc.debugGCSlice(budget);
#ifdef DEBUG
    CHECK(map->zone()->lastZoneGroupIndex() < delegateRoot->zone()->lastZoneGroupIndex());
#endif

    /* Add our entry to the weakmap. */
    JS::RootedValue val(cx, JS::Int32Value(1));
    CHECK(SetWeakMapEntry(cx, map, key, val));
    CHECK(checkSize(map, 1));

    /* Check the delegate keeps the entry alive even if the key is not reachable. */
    key = nullptr;
    CHECK(newCCW(map, delegateRoot));
    budget = js::SliceBudget(js::WorkBudget(100000));
    cx->gc.startDebugGC(GC_NORMAL, budget);
    while (JS::IsIncrementalGCInProgress(cx))
        cx->gc.debugGCSlice(budget);
    CHECK(checkSize(map, 1));

    /*
     * Check that the zones finished marking at the same time, which is
     * necessary because of the presence of the delegate and the CCW.
     */
#ifdef DEBUG
    CHECK(map->zone()->lastZoneGroupIndex() == delegateRoot->zone()->lastZoneGroupIndex());
#endif

    /* Check that when the delegate becomes unreachable the entry is removed. */
    delegateRoot = nullptr;
    keyDelegate = nullptr;
    JS_GC(cx);
    CHECK(checkSize(map, 0));

    return true;
}

static void DelegateObjectMoved(JSObject* obj, const JSObject* old)
{
    if (!keyDelegate)
        return;  // Object got moved before we set keyDelegate to point to it.

    MOZ_RELEASE_ASSERT(keyDelegate == old);
    keyDelegate = obj;
}

static JSObject* GetKeyDelegate(JSObject* obj)
{
    return keyDelegate;
}

JSObject* newKey()
{
    static const js::ClassExtension keyClassExtension = {
        GetKeyDelegate
    };

    static const js::Class keyClass = {
        "keyWithDelegate",
        JSCLASS_HAS_PRIVATE | JSCLASS_HAS_RESERVED_SLOTS(1),
        JS_NULL_CLASS_OPS,
        JS_NULL_CLASS_SPEC,
        &keyClassExtension,
        JS_NULL_OBJECT_OPS
    };

    JS::RootedObject key(cx, JS_NewObject(cx, Jsvalify(&keyClass)));
    if (!key)
        return nullptr;

    return key;
}

JSObject* newCCW(JS::HandleObject sourceZone, JS::HandleObject destZone)
{
    /*
     * Now ensure that this zone will be swept first by adding a cross
     * compartment wrapper to a new objct in the same zone as the
     * delegate obejct.
     */
    JS::RootedObject object(cx);
    {
        JSAutoCompartment ac(cx, destZone);
        object = JS_NewPlainObject(cx);
        if (!object)
            return nullptr;
    }
    {
        JSAutoCompartment ac(cx, sourceZone);
        if (!JS_WrapObject(cx, &object))
            return nullptr;
    }

    // In order to test the SCC algorithm, we need the wrapper/wrappee to be
    // tenured.
    cx->gc.evictNursery();

    return object;
}

JSObject* newDelegate()
{
    static const js::ClassOps delegateClassOps = {
        nullptr, /* addProperty */
        nullptr, /* delProperty */
        nullptr, /* getProperty */
        nullptr, /* setProperty */
        nullptr, /* enumerate */
        nullptr, /* resolve */
        nullptr, /* mayResolve */
        nullptr, /* finalize */
        nullptr, /* call */
        nullptr, /* hasInstance */
        nullptr, /* construct */
        JS_GlobalObjectTraceHook,
    };

    static const js::ClassExtension delegateClassExtension = {
        nullptr,
        DelegateObjectMoved
    };

    static const js::Class delegateClass = {
        "delegate",
        JSCLASS_GLOBAL_FLAGS | JSCLASS_HAS_RESERVED_SLOTS(1),
        &delegateClassOps,
        JS_NULL_CLASS_SPEC,
        &delegateClassExtension,
        JS_NULL_OBJECT_OPS
    };

    /* Create the global object. */
    JS::CompartmentOptions options;
    options.behaviors().setVersion(JSVERSION_LATEST);

    JS::RootedObject global(cx, JS_NewGlobalObject(cx, Jsvalify(&delegateClass), nullptr,
                                                   JS::FireOnNewGlobalHook, options));
    if (!global)
        return nullptr;

    JS_SetReservedSlot(global, 0, JS::Int32Value(42));
    return global;
}

bool
checkSize(JS::HandleObject map, uint32_t expected)
{
    JS::RootedObject keys(cx);
    CHECK(JS_NondeterministicGetWeakMapKeys(cx, map, &keys));

    uint32_t length;
    CHECK(JS_GetArrayLength(cx, keys, &length));
    CHECK(length == expected);

    return true;
}
END_TEST(testWeakMap_keyDelegates)