C++ mozilla::PodZero方法代码示例

void
Statistics::endGC()
{
    for (auto j : MakeRange(NumTimingArrays))
        for (int i = 0; i < PHASE_LIMIT; i++)
            phaseTotals[j][i] += phaseTimes[j][i];

    int64_t total, longest;
    gcDuration(&total, &longest);

    int64_t sccTotal, sccLongest;
    sccDurations(&sccTotal, &sccLongest);

    runtime->addTelemetry(JS_TELEMETRY_GC_IS_COMPARTMENTAL, !zoneStats.isCollectingAllZones());
    runtime->addTelemetry(JS_TELEMETRY_GC_MS, t(total));
    runtime->addTelemetry(JS_TELEMETRY_GC_MAX_PAUSE_MS, t(longest));
    int64_t markTotal = SumPhase(PHASE_MARK, phaseTimes);
    int64_t markRootsTotal = SumPhase(PHASE_MARK_ROOTS, phaseTimes);
    runtime->addTelemetry(JS_TELEMETRY_GC_MARK_MS, t(markTotal));
    runtime->addTelemetry(JS_TELEMETRY_GC_SWEEP_MS, t(phaseTimes[PHASE_DAG_NONE][PHASE_SWEEP]));
    if (runtime->gc.isCompactingGc()) {
        runtime->addTelemetry(JS_TELEMETRY_GC_COMPACT_MS,
                              t(phaseTimes[PHASE_DAG_NONE][PHASE_COMPACT]));
    }
    runtime->addTelemetry(JS_TELEMETRY_GC_MARK_ROOTS_MS, t(markRootsTotal));
    runtime->addTelemetry(JS_TELEMETRY_GC_MARK_GRAY_MS, t(phaseTimes[PHASE_DAG_NONE][PHASE_SWEEP_MARK_GRAY]));
    runtime->addTelemetry(JS_TELEMETRY_GC_NON_INCREMENTAL, !!nonincrementalReason_);
    runtime->addTelemetry(JS_TELEMETRY_GC_INCREMENTAL_DISABLED, !runtime->gc.isIncrementalGCAllowed());
    runtime->addTelemetry(JS_TELEMETRY_GC_SCC_SWEEP_TOTAL_MS, t(sccTotal));
    runtime->addTelemetry(JS_TELEMETRY_GC_SCC_SWEEP_MAX_PAUSE_MS, t(sccLongest));

    if (!aborted) {
        double mmu50 = computeMMU(50 * PRMJ_USEC_PER_MSEC);
        runtime->addTelemetry(JS_TELEMETRY_GC_MMU_50, mmu50 * 100);
    }

    if (fp)
        printStats();

    // Clear the timers at the end of a GC because we accumulate time in
    // between GCs for some (which come before PHASE_GC_BEGIN in the list.)
    PodZero(&phaseStartTimes[PHASE_GC_BEGIN], PHASE_LIMIT - PHASE_GC_BEGIN);
    for (size_t d = PHASE_DAG_NONE; d < NumTimingArrays; d++)
        PodZero(&phaseTimes[d][PHASE_GC_BEGIN], PHASE_LIMIT - PHASE_GC_BEGIN);

    // Clear the OOM flag but only if we are not in a nested GC.
    if (gcDepth == 1)
        aborted = false;
}

bool
js_ReportErrorVA(JSContext *cx, unsigned flags, const char *format, va_list ap)
{
    char *message;
    jschar *ucmessage;
    size_t messagelen;
    JSErrorReport report;
    bool warning;

    if (checkReportFlags(cx, &flags))
        return true;

    message = JS_vsmprintf(format, ap);
    if (!message)
        return false;
    messagelen = strlen(message);

    PodZero(&report);
    report.flags = flags;
    report.errorNumber = JSMSG_USER_DEFINED_ERROR;
    report.ucmessage = ucmessage = InflateString(cx, message, &messagelen);
    PopulateReportBlame(cx, &report);

    warning = JSREPORT_IS_WARNING(report.flags);

    ReportError(cx, message, &report, nullptr, nullptr);
    js_free(message);
    js_free(ucmessage);
    return warning;
}

/*
 * Since memory has been exhausted, avoid the normal error-handling path which
 * allocates an error object, report and callstack. If code is running, simply
 * throw the static atom "out of memory". If code is not running, call the
 * error reporter directly.
 *
 * Furthermore, callers of js_ReportOutOfMemory (viz., malloc) assume a GC does
 * not occur, so GC must be avoided or suppressed.
 */
void
js_ReportOutOfMemory(ThreadSafeContext *cxArg)
{
    if (!cxArg->isJSContext())
        return;
    JSContext *cx = cxArg->asJSContext();

    cx->runtime()->hadOutOfMemory = true;

    if (JS_IsRunning(cx)) {
        cx->setPendingException(StringValue(cx->names().outOfMemory));
        return;
    }

    /* Get the message for this error, but we don't expand any arguments. */
    const JSErrorFormatString *efs =
        js_GetLocalizedErrorMessage(cx, NULL, NULL, JSMSG_OUT_OF_MEMORY);
    const char *msg = efs ? efs->format : "Out of memory";

    /* Fill out the report, but don't do anything that requires allocation. */
    JSErrorReport report;
    PodZero(&report);
    report.flags = JSREPORT_ERROR;
    report.errorNumber = JSMSG_OUT_OF_MEMORY;
    PopulateReportBlame(cx, &report);

    /* Report the error. */
    if (JSErrorReporter onError = cx->errorReporter) {
        AutoSuppressGC suppressGC(cx);
        onError(cx, msg, &report);
    }
}

void
Statistics::endGC()
{
    for (size_t j = 0; j < MAX_MULTIPARENT_PHASES + 1; j++)
        for (int i = 0; i < PHASE_LIMIT; i++)
            phaseTotals[j][i] += phaseTimes[j][i];

    int64_t total, longest;
    gcDuration(&total, &longest);

    int64_t sccTotal, sccLongest;
    sccDurations(&sccTotal, &sccLongest);

    runtime->addTelemetry(JS_TELEMETRY_GC_IS_COMPARTMENTAL, !zoneStats.isCollectingAllZones());
    runtime->addTelemetry(JS_TELEMETRY_GC_MS, t(total));
    runtime->addTelemetry(JS_TELEMETRY_GC_MAX_PAUSE_MS, t(longest));
    int64_t markTotal = SumPhase(PHASE_MARK, phaseTimes);
    int64_t markRootsTotal = SumPhase(PHASE_MARK_ROOTS, phaseTimes);
    runtime->addTelemetry(JS_TELEMETRY_GC_MARK_MS, t(markTotal));
    runtime->addTelemetry(JS_TELEMETRY_GC_SWEEP_MS, t(phaseTimes[PHASE_DAG_NONE][PHASE_SWEEP]));
    runtime->addTelemetry(JS_TELEMETRY_GC_MARK_ROOTS_MS, t(markRootsTotal));
    runtime->addTelemetry(JS_TELEMETRY_GC_MARK_GRAY_MS, t(phaseTimes[PHASE_DAG_NONE][PHASE_SWEEP_MARK_GRAY]));
    runtime->addTelemetry(JS_TELEMETRY_GC_NON_INCREMENTAL, !!nonincrementalReason_);
    runtime->addTelemetry(JS_TELEMETRY_GC_INCREMENTAL_DISABLED, !runtime->gc.isIncrementalGCAllowed());
    runtime->addTelemetry(JS_TELEMETRY_GC_SCC_SWEEP_TOTAL_MS, t(sccTotal));
    runtime->addTelemetry(JS_TELEMETRY_GC_SCC_SWEEP_MAX_PAUSE_MS, t(sccLongest));

    if (!aborted) {
        double mmu50 = computeMMU(50 * PRMJ_USEC_PER_MSEC);
        runtime->addTelemetry(JS_TELEMETRY_GC_MMU_50, mmu50 * 100);
    }

    if (fp)
        printStats();

    if (!aborted)
        Debugger::onGarbageCollection(runtime, *this);

    // Clear the timers at the end of a GC because we accumulate time in
    // between GCs for some (which come before PHASE_GC_BEGIN in the list.)
    PodZero(&phaseStartTimes[PHASE_GC_BEGIN], PHASE_LIMIT - PHASE_GC_BEGIN);
    for (size_t d = PHASE_DAG_NONE; d < MAX_MULTIPARENT_PHASES + 1; d++)
        PodZero(&phaseTimes[d][PHASE_GC_BEGIN], PHASE_LIMIT - PHASE_GC_BEGIN);

    aborted = false;
}

/*
 * Since memory has been exhausted, avoid the normal error-handling path which
 * allocates an error object, report and callstack. If code is running, simply
 * throw the static atom "out of memory". If code is not running, call the
 * error reporter directly.
 *
 * Furthermore, callers of js_ReportOutOfMemory (viz., malloc) assume a GC does
 * not occur, so GC must be avoided or suppressed.
 */
void
js_ReportOutOfMemory(ThreadSafeContext *cxArg)
{
#ifdef JS_MORE_DETERMINISTIC
    /*
     * OOMs are non-deterministic, especially across different execution modes
     * (e.g. interpreter vs JIT). In more-deterministic builds, print to stderr
     * so that the fuzzers can detect this.
     */
    fprintf(stderr, "js_ReportOutOfMemory called\n");
#endif

    if (cxArg->isForkJoinSlice()) {
        cxArg->asForkJoinSlice()->setPendingAbortFatal(ParallelBailoutOutOfMemory);
        return;
    }

    if (!cxArg->isJSContext())
        return;
    JSContext *cx = cxArg->asJSContext();

    cx->runtime()->hadOutOfMemory = true;

    if (JS_IsRunning(cx)) {
        cx->setPendingException(StringValue(cx->names().outOfMemory));
        return;
    }

    /* Get the message for this error, but we don't expand any arguments. */
    const JSErrorFormatString *efs =
        js_GetLocalizedErrorMessage(cx, nullptr, nullptr, JSMSG_OUT_OF_MEMORY);
    const char *msg = efs ? efs->format : "Out of memory";

    /* Fill out the report, but don't do anything that requires allocation. */
    JSErrorReport report;
    PodZero(&report);
    report.flags = JSREPORT_ERROR;
    report.errorNumber = JSMSG_OUT_OF_MEMORY;
    PopulateReportBlame(cx, &report);

    /* Report the error. */
    if (JSErrorReporter onError = cx->errorReporter) {
        AutoSuppressGC suppressGC(cx);
        onError(cx, msg, &report);
    }

    /*
     * We would like to enforce the invariant that any exception reported
     * during an OOM situation does not require wrapping. Besides avoiding
     * allocation when memory is low, this reduces the number of places where
     * we might need to GC.
     *
     * When JS code is running, we set the pending exception to an atom, which
     * does not need wrapping. If no JS code is running, no exception should be
     * set at all.
     */
    JS_ASSERT(!cx->isExceptionPending());
}

NativeIterator*
NativeIterator::allocateIterator(JSContext* cx, uint32_t numGuards, uint32_t plength)
{
    JS_STATIC_ASSERT(sizeof(ReceiverGuard) == 2 * sizeof(void*));

    size_t extraLength = plength + numGuards * 2;
    NativeIterator* ni = cx->zone()->pod_malloc_with_extra<NativeIterator, void*>(extraLength);
    if (!ni) {
        ReportOutOfMemory(cx);
        return nullptr;
    }

    void** extra = reinterpret_cast<void**>(ni + 1);
    PodZero(ni);
    PodZero(extra, extraLength);
    ni->props_array = ni->props_cursor = reinterpret_cast<GCPtrFlatString*>(extra);
    ni->props_end = ni->props_array + plength;
    return ni;
}

Statistics::Statistics(JSRuntime* rt)
  : runtime(rt),
    startupTime(PRMJ_Now()),
    fp(nullptr),
    gcDepth(0),
    nonincrementalReason_(gc::AbortReason::None),
    timedGCStart(0),
    preBytes(0),
    maxPauseInInterval(0),
    phaseNestingDepth(0),
    activeDagSlot(PHASE_DAG_NONE),
    suspended(0),
    sliceCallback(nullptr),
    nurseryCollectionCallback(nullptr),
    aborted(false),
    enableProfiling_(false),
    sliceCount_(0)
{
    PodArrayZero(phaseTotals);
    PodArrayZero(counts);
    PodArrayZero(phaseStartTimes);
    for (auto d : MakeRange(NumTimingArrays))
        PodArrayZero(phaseTimes[d]);

    const char* env = getenv("MOZ_GCTIMER");
    if (env) {
        if (strcmp(env, "none") == 0) {
            fp = nullptr;
        } else if (strcmp(env, "stdout") == 0) {
            fp = stdout;
        } else if (strcmp(env, "stderr") == 0) {
            fp = stderr;
        } else {
            fp = fopen(env, "a");
            if (!fp)
                MOZ_CRASH("Failed to open MOZ_GCTIMER log file.");
        }
    }

    env = getenv("JS_GC_PROFILE");
    if (env) {
        if (0 == strcmp(env, "help")) {
            fprintf(stderr, "JS_GC_PROFILE=N\n"
                    "\tReport major GC's taking more than N milliseconds.\n");
            exit(0);
        }
        enableProfiling_ = true;
        profileThreshold_ = atoi(env);
    }

    PodZero(&totalTimes_);
}

CodeRange::CodeRange(Kind kind, Offsets offsets)
  : funcIndex_(0),
    funcLineOrBytecode_(0),
    begin_(offsets.begin),
    profilingReturn_(0),
    end_(offsets.end)
{
    PodZero(&u);  // zero padding for Valgrind
    u.kind_ = kind;

    MOZ_ASSERT(begin_ <= end_);
    MOZ_ASSERT(u.kind_ == Entry || u.kind_ == Inline);
}

void
NewObjectCache::clearNurseryObjects(JSRuntime* rt)
{
    for (unsigned i = 0; i < mozilla::ArrayLength(entries); ++i) {
        Entry& e = entries[i];
        NativeObject* obj = reinterpret_cast<NativeObject*>(&e.templateObject);
        if (IsInsideNursery(e.key) ||
            rt->gc.nursery.isInside(obj->slots_) ||
            rt->gc.nursery.isInside(obj->elements_))
        {
            PodZero(&e);
        }
    }
}

void
Statistics::endGC()
{
    crash::SnapshotGCStack();

    for (int i = 0; i < PHASE_LIMIT; i++)
        phaseTotals[i] += phaseTimes[i];

    int64_t total, longest;
    gcDuration(&total, &longest);

    int64_t sccTotal, sccLongest;
    sccDurations(&sccTotal, &sccLongest);

    runtime->addTelemetry(JS_TELEMETRY_GC_IS_COMPARTMENTAL, !zoneStats.isCollectingAllZones());
    runtime->addTelemetry(JS_TELEMETRY_GC_MS, t(total));
    runtime->addTelemetry(JS_TELEMETRY_GC_MAX_PAUSE_MS, t(longest));
    runtime->addTelemetry(JS_TELEMETRY_GC_MARK_MS, t(phaseTimes[PHASE_MARK]));
    runtime->addTelemetry(JS_TELEMETRY_GC_SWEEP_MS, t(phaseTimes[PHASE_SWEEP]));
    runtime->addTelemetry(JS_TELEMETRY_GC_MARK_ROOTS_MS, t(phaseTimes[PHASE_MARK_ROOTS]));
    runtime->addTelemetry(JS_TELEMETRY_GC_MARK_GRAY_MS, t(phaseTimes[PHASE_SWEEP_MARK_GRAY]));
    runtime->addTelemetry(JS_TELEMETRY_GC_NON_INCREMENTAL, !!nonincrementalReason);
    runtime->addTelemetry(JS_TELEMETRY_GC_INCREMENTAL_DISABLED, !runtime->gc.isIncrementalGCAllowed());
    runtime->addTelemetry(JS_TELEMETRY_GC_SCC_SWEEP_TOTAL_MS, t(sccTotal));
    runtime->addTelemetry(JS_TELEMETRY_GC_SCC_SWEEP_MAX_PAUSE_MS, t(sccLongest));
 
    double mmu50 = computeMMU(50 * PRMJ_USEC_PER_MSEC);
    runtime->addTelemetry(JS_TELEMETRY_GC_MMU_50, mmu50 * 100);

    if (fp)
        printStats();

    // Clear the timers at the end of a GC because we accumulate time in
    // between GCs for some (which come before PHASE_GC_BEGIN in the list.)
    PodZero(&phaseStartTimes[PHASE_GC_BEGIN], PHASE_LIMIT - PHASE_GC_BEGIN);
    PodZero(&phaseTimes[PHASE_GC_BEGIN], PHASE_LIMIT - PHASE_GC_BEGIN);
}

NativeIterator*
NativeIterator::allocateSentinel(JSContext* maybecx)
{
    NativeIterator* ni = js_pod_malloc<NativeIterator>();
    if (!ni) {
        if (maybecx)
            ReportOutOfMemory(maybecx);
        return nullptr;
    }

    PodZero(ni);

    ni->next_ = ni;
    ni->prev_ = ni;
    return ni;
}

/*
 * Since memory has been exhausted, avoid the normal error-handling path which
 * allocates an error object, report and callstack. If code is running, simply
 * throw the static atom "out of memory". If code is not running, call the
 * error reporter directly.
 *
 * Furthermore, callers of js_ReportOutOfMemory (viz., malloc) assume a GC does
 * not occur, so GC must be avoided or suppressed.
 */
void
js_ReportOutOfMemory(ThreadSafeContext *cxArg)
{
    if (!cxArg->isJSContext())
        return;
    JSContext *cx = cxArg->asJSContext();

    cx->runtime()->hadOutOfMemory = true;

    if (JS_IsRunning(cx)) {
        cx->setPendingException(StringValue(cx->names().outOfMemory));
        return;
    }

    /* Get the message for this error, but we don't expand any arguments. */
    const JSErrorFormatString *efs =
        js_GetLocalizedErrorMessage(cx, NULL, NULL, JSMSG_OUT_OF_MEMORY);
    const char *msg = efs ? efs->format : "Out of memory";

    /* Fill out the report, but don't do anything that requires allocation. */
    JSErrorReport report;
    PodZero(&report);
    report.flags = JSREPORT_ERROR;
    report.errorNumber = JSMSG_OUT_OF_MEMORY;
    PopulateReportBlame(cx, &report);

    /* Report the error. */
    if (JSErrorReporter onError = cx->errorReporter) {
        AutoSuppressGC suppressGC(cx);
        onError(cx, msg, &report);
    }

    /*
     * We would like to enforce the invariant that any exception reported
     * during an OOM situation does not require wrapping. Besides avoiding
     * allocation when memory is low, this reduces the number of places where
     * we might need to GC.
     *
     * When JS code is running, we set the pending exception to an atom, which
     * does not need wrapping. If no JS code is running, no exception should be
     * set at all.
     */
    JS_ASSERT(!cx->isExceptionPending());
}

//.........这里部分代码省略.........
    numCompartments(0),
    localeCallbacks(nullptr),
    defaultLocale(nullptr),
    defaultVersion_(JSVERSION_DEFAULT),
#ifdef JS_THREADSAFE
    ownerThread_(nullptr),
#endif
    tempLifoAlloc(TEMP_LIFO_ALLOC_PRIMARY_CHUNK_SIZE),
    freeLifoAlloc(TEMP_LIFO_ALLOC_PRIMARY_CHUNK_SIZE),
    execAlloc_(nullptr),
#ifdef JS_YARR
    bumpAlloc_(nullptr),
#endif
    jitRuntime_(nullptr),
    selfHostingGlobal_(nullptr),
    nativeStackBase(0),
    cxCallback(nullptr),
    destroyCompartmentCallback(nullptr),
    destroyZoneCallback(nullptr),
    sweepZoneCallback(nullptr),
    compartmentNameCallback(nullptr),
    activityCallback(nullptr),
    activityCallbackArg(nullptr),
#ifdef JS_THREADSAFE
    requestDepth(0),
# ifdef DEBUG
    checkRequestDepth(0),
# endif
#endif
#ifdef DEBUG
    activeContext(nullptr),
#endif
    gc(thisFromCtor()),
    gcInitialized(false),
#if defined(JS_ARM_SIMULATOR) || defined(JS_MIPS_SIMULATOR)
    simulatorRuntime_(nullptr),
#endif
    NaNValue(DoubleNaNValue()),
    negativeInfinityValue(DoubleValue(NegativeInfinity<double>())),
    positiveInfinityValue(DoubleValue(PositiveInfinity<double>())),
    emptyString(nullptr),
    debugMode(false),
    spsProfiler(thisFromCtor()),
    profilingScripts(false),
    hadOutOfMemory(false),
    haveCreatedContext(false),
    data(nullptr),
    signalHandlersInstalled_(false),
    defaultFreeOp_(thisFromCtor(), false),
    debuggerMutations(0),
    securityCallbacks(const_cast<JSSecurityCallbacks *>(&NullSecurityCallbacks)),
    DOMcallbacks(nullptr),
    destroyPrincipals(nullptr),
    structuredCloneCallbacks(nullptr),
    telemetryCallback(nullptr),
    propertyRemovals(0),
#if !EXPOSE_INTL_API
    thousandsSeparator(0),
    decimalSeparator(0),
    numGrouping(0),
#endif
    mathCache_(nullptr),
    activeCompilations_(0),
    keepAtoms_(0),
    trustedPrincipals_(nullptr),
    beingDestroyed_(false),
    atoms_(nullptr),
    atomsCompartment_(nullptr),
    staticStrings(nullptr),
    commonNames(nullptr),
    permanentAtoms(nullptr),
    wrapObjectCallbacks(&DefaultWrapObjectCallbacks),
    preserveWrapperCallback(nullptr),
    jitSupportsFloatingPoint(false),
    ionPcScriptCache(nullptr),
    threadPool(this),
    defaultJSContextCallback(nullptr),
    ctypesActivityCallback(nullptr),
    forkJoinWarmup(0),
    useHelperThreads_(useHelperThreads),
    parallelIonCompilationEnabled_(true),
    parallelParsingEnabled_(true),
    isWorkerRuntime_(false),
#ifdef DEBUG
    enteredPolicy(nullptr),
#endif
    largeAllocationFailureCallback(nullptr),
    oomCallback(nullptr)
{
    liveRuntimesCount++;

    setGCMode(JSGC_MODE_GLOBAL);

    /* Initialize infallibly first, so we can goto bad and JS_DestroyRuntime. */
    JS_INIT_CLIST(&onNewGlobalObjectWatchers);

    PodZero(&debugHooks);
    PodArrayZero(nativeStackQuota);
    PodZero(&asmJSCacheOps);
}

void
Statistics::endSlice()
{
    if (!aborted) {
        slices.back().end = PRMJ_Now();
        slices.back().endTimestamp = JS_GetCurrentEmbedderTime();
        slices.back().endFaults = GetPageFaultCount();
        slices.back().finalState = runtime->gc.state();

        int64_t sliceTime = slices.back().end - slices.back().start;
        runtime->addTelemetry(JS_TELEMETRY_GC_SLICE_MS, t(sliceTime));
        runtime->addTelemetry(JS_TELEMETRY_GC_RESET, slices.back().wasReset());
        if (slices.back().wasReset())
            runtime->addTelemetry(JS_TELEMETRY_GC_RESET_REASON, uint32_t(slices.back().resetReason));

        if (slices.back().budget.isTimeBudget()) {
            int64_t budget_ms = slices.back().budget.timeBudget.budget;
            runtime->addTelemetry(JS_TELEMETRY_GC_BUDGET_MS, budget_ms);
            if (budget_ms == runtime->gc.defaultSliceBudget())
                runtime->addTelemetry(JS_TELEMETRY_GC_ANIMATION_MS, t(sliceTime));

            // Record any phase that goes more than 2x over its budget.
            if (sliceTime > 2 * budget_ms * 1000) {
                Phase longest = LongestPhase(slices.back().phaseTimes);
                runtime->addTelemetry(JS_TELEMETRY_GC_SLOW_PHASE, phases[longest].telemetryBucket);
            }
        }

        sliceCount_++;
    }

    bool last = !runtime->gc.isIncrementalGCInProgress();
    if (last)
        endGC();

    if (enableProfiling_ && !aborted && slices.back().duration() >= profileThreshold_)
        printSliceProfile();

    // Slice callbacks should only fire for the outermost level.
    if (gcDepth == 1 && !aborted) {
        bool wasFullGC = zoneStats.isCollectingAllZones();
        if (sliceCallback)
            (*sliceCallback)(runtime->contextFromMainThread(),
                             last ? JS::GC_CYCLE_END : JS::GC_SLICE_END,
                             JS::GCDescription(!wasFullGC, gckind, slices.back().reason));
    }

    /* Do this after the slice callback since it uses these values. */
    if (last) {
        PodArrayZero(counts);

        // Clear the timers at the end of a GC because we accumulate time in
        // between GCs for some (which come before PHASE_GC_BEGIN in the list.)
        PodZero(&phaseStartTimes[PHASE_GC_BEGIN], PHASE_LIMIT - PHASE_GC_BEGIN);
        for (size_t d = PHASE_DAG_NONE; d < NumTimingArrays; d++)
            PodZero(&phaseTimes[d][PHASE_GC_BEGIN], PHASE_LIMIT - PHASE_GC_BEGIN);
    }

    gcDepth--;
    MOZ_ASSERT(gcDepth >= 0);
}

 AutoPropertyDescArray(JSContext *cx)
   : cx_(cx)
 {
     PodZero(&descArray_);
 }