gecko-dev/dom/base/nsJSEnvironment.cpp
2017-10-11 13:15:26 +02:00

2980 lines
87 KiB
C++

/* -*- 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/. */
#include "nsError.h"
#include "nsJSEnvironment.h"
#include "nsIScriptGlobalObject.h"
#include "nsIScriptObjectPrincipal.h"
#include "nsIDOMChromeWindow.h"
#include "nsPIDOMWindow.h"
#include "nsIScriptSecurityManager.h"
#include "nsDOMCID.h"
#include "nsIServiceManager.h"
#include "nsIXPConnect.h"
#include "nsCOMPtr.h"
#include "nsISupportsPrimitives.h"
#include "nsReadableUtils.h"
#include "nsDOMJSUtils.h"
#include "nsJSUtils.h"
#include "nsIDocShell.h"
#include "nsIDocShellTreeItem.h"
#include "nsPresContext.h"
#include "nsIConsoleService.h"
#include "nsIScriptError.h"
#include "nsIInterfaceRequestor.h"
#include "nsIInterfaceRequestorUtils.h"
#include "nsIPrompt.h"
#include "nsIObserverService.h"
#include "nsITimer.h"
#include "nsAtom.h"
#include "nsContentUtils.h"
#include "mozilla/EventDispatcher.h"
#include "nsIContent.h"
#include "nsCycleCollector.h"
#include "nsXPCOMCIDInternal.h"
#include "nsIXULRuntime.h"
#include "nsTextFormatter.h"
#ifdef XP_WIN
#include <process.h>
#define getpid _getpid
#else
#include <unistd.h> // for getpid()
#endif
#include "xpcpublic.h"
#include "jsapi.h"
#include "jswrapper.h"
#include "js/SliceBudget.h"
#include "nsIArray.h"
#include "nsIObjectInputStream.h"
#include "nsIObjectOutputStream.h"
#include "WrapperFactory.h"
#include "nsGlobalWindow.h"
#include "nsScriptNameSpaceManager.h"
#include "mozilla/AutoRestore.h"
#include "mozilla/MainThreadIdlePeriod.h"
#include "mozilla/StaticPtr.h"
#include "mozilla/dom/DOMException.h"
#include "mozilla/dom/DOMExceptionBinding.h"
#include "mozilla/dom/Element.h"
#include "mozilla/dom/ErrorEvent.h"
#include "mozilla/dom/FetchUtil.h"
#include "mozilla/dom/ScriptSettings.h"
#include "mozilla/CycleCollectedJSRuntime.h"
#include "mozilla/SystemGroup.h"
#include "nsRefreshDriver.h"
#include "nsJSPrincipals.h"
#ifdef XP_MACOSX
// AssertMacros.h defines 'check' and conflicts with AccessCheck.h
#undef check
#endif
#include "AccessCheck.h"
#include "mozilla/Logging.h"
#include "prthread.h"
#include "mozilla/Preferences.h"
#include "mozilla/Telemetry.h"
#include "mozilla/dom/BindingUtils.h"
#include "mozilla/Attributes.h"
#include "mozilla/dom/asmjscache/AsmJSCache.h"
#include "mozilla/dom/CanvasRenderingContext2DBinding.h"
#include "mozilla/ContentEvents.h"
#include "mozilla/CycleCollectedJSContext.h"
#include "nsCycleCollectionNoteRootCallback.h"
#include "GeckoProfiler.h"
#include "mozilla/IdleTaskRunner.h"
#include "nsIDocShell.h"
#include "nsIPresShell.h"
#include "nsViewManager.h"
#include "mozilla/EventStateManager.h"
using namespace mozilla;
using namespace mozilla::dom;
const size_t gStackSize = 8192;
// Thank you Microsoft!
#ifdef CompareString
#undef CompareString
#endif
#define NS_SHRINK_GC_BUFFERS_DELAY 4000 // ms
// The amount of time we wait from the first request to GC to actually
// doing the first GC.
#define NS_FIRST_GC_DELAY 10000 // ms
#define NS_FULL_GC_DELAY 60000 // ms
// The default amount of time to wait from the user being idle to starting a
// shrinking GC.
#define NS_DEAULT_INACTIVE_GC_DELAY 300000 // ms
// Maximum amount of time that should elapse between incremental GC slices
#define NS_INTERSLICE_GC_DELAY 100 // ms
// The amount of time we wait between a request to CC (after GC ran)
// and doing the actual CC.
#define NS_CC_DELAY 6000 // ms
#define NS_CC_SKIPPABLE_DELAY 250 // ms
// ForgetSkippable is usually fast, so we can use small budgets.
// This isn't a real budget but a hint to IdleTaskRunner whether there
// is enough time to call ForgetSkippable.
static const int64_t kForgetSkippableSliceDuration = 2;
// Maximum amount of time that should elapse between incremental CC slices
static const int64_t kICCIntersliceDelay = 64; // ms
// Time budget for an incremental CC slice when using timer to run it.
static const int64_t kICCSliceBudget = 3; // ms
// Minimum budget for an incremental CC slice when using idle time to run it.
static const int64_t kIdleICCSliceBudget = 2; // ms
// Maximum total duration for an ICC
static const uint32_t kMaxICCDuration = 2000; // ms
// Force a CC after this long if there's more than NS_CC_FORCED_PURPLE_LIMIT
// objects in the purple buffer.
#define NS_CC_FORCED (2 * 60 * PR_USEC_PER_SEC) // 2 min
#define NS_CC_FORCED_PURPLE_LIMIT 10
// Don't allow an incremental GC to lock out the CC for too long.
#define NS_MAX_CC_LOCKEDOUT_TIME (30 * PR_USEC_PER_SEC) // 30 seconds
// Trigger a CC if the purple buffer exceeds this size when we check it.
#define NS_CC_PURPLE_LIMIT 200
// Large value used to specify that a script should run essentially forever
#define NS_UNLIMITED_SCRIPT_RUNTIME (0x40000000LL << 32)
// if you add statics here, add them to the list in StartupJSEnvironment
static nsITimer *sGCTimer;
static nsITimer *sShrinkingGCTimer;
static StaticRefPtr<IdleTaskRunner> sCCRunner;
static StaticRefPtr<IdleTaskRunner> sICCRunner;
static nsITimer *sFullGCTimer;
static StaticRefPtr<IdleTaskRunner> sInterSliceGCRunner;
static TimeStamp sLastCCEndTime;
static bool sCCLockedOut;
static PRTime sCCLockedOutTime;
static JS::GCSliceCallback sPrevGCSliceCallback;
static bool sHasRunGC;
// The number of currently pending document loads. This count isn't
// guaranteed to always reflect reality and can't easily as we don't
// have an easy place to know when a load ends or is interrupted in
// all cases. This counter also gets reset if we end up GC'ing while
// we're waiting for a slow page to load. IOW, this count may be 0
// even when there are pending loads.
static uint32_t sPendingLoadCount;
static bool sLoadingInProgress;
static uint32_t sCCollectedWaitingForGC;
static uint32_t sCCollectedZonesWaitingForGC;
static uint32_t sLikelyShortLivingObjectsNeedingGC;
static bool sPostGCEventsToConsole;
static bool sPostGCEventsToObserver;
static int32_t sCCRunnerFireCount = 0;
static uint32_t sMinForgetSkippableTime = UINT32_MAX;
static uint32_t sMaxForgetSkippableTime = 0;
static uint32_t sTotalForgetSkippableTime = 0;
static uint32_t sRemovedPurples = 0;
static uint32_t sForgetSkippableBeforeCC = 0;
static uint32_t sPreviousSuspectedCount = 0;
static uint32_t sCleanupsSinceLastGC = UINT32_MAX;
static bool sNeedsFullCC = false;
static bool sNeedsFullGC = false;
static bool sNeedsGCAfterCC = false;
static bool sIncrementalCC = false;
static int32_t sActiveIntersliceGCBudget = 5; // ms;
static nsScriptNameSpaceManager *gNameSpaceManager;
static PRTime sFirstCollectionTime;
static bool sIsInitialized;
static bool sDidShutdown;
static bool sShuttingDown;
// nsJSEnvironmentObserver observes the memory-pressure notifications
// and forces a garbage collection and cycle collection when it happens, if
// the appropriate pref is set.
static bool sGCOnMemoryPressure;
// nsJSEnvironmentObserver observes the user-interaction-inactive notifications
// and triggers a shrinking a garbage collection if the user is still inactive
// after NS_SHRINKING_GC_DELAY ms later, if the appropriate pref is set.
static bool sCompactOnUserInactive;
static uint32_t sCompactOnUserInactiveDelay = NS_DEAULT_INACTIVE_GC_DELAY;
static bool sIsCompactingOnUserInactive = false;
static TimeDuration sGCUnnotifiedTotalTime;
static const char*
ProcessNameForCollectorLog()
{
return XRE_GetProcessType() == GeckoProcessType_Default ?
"default" : "content";
}
namespace xpc {
// This handles JS Exceptions (via ExceptionStackOrNull), as well as DOM and XPC
// Exceptions.
//
// Note that the returned object is _not_ wrapped into the compartment of
// exceptionValue.
JSObject*
FindExceptionStackForConsoleReport(nsPIDOMWindowInner* win,
JS::HandleValue exceptionValue)
{
if (!exceptionValue.isObject()) {
return nullptr;
}
if (win && win->InnerObjectsFreed()) {
// Pretend like we have no stack, so we don't end up keeping the global
// alive via the stack.
return nullptr;
}
JS::RootingContext* rcx = RootingCx();
JS::RootedObject exceptionObject(rcx, &exceptionValue.toObject());
JSObject* stackObject = ExceptionStackOrNull(exceptionObject);
if (stackObject) {
return stackObject;
}
// It is not a JS Exception, try DOM Exception.
RefPtr<Exception> exception;
UNWRAP_OBJECT(DOMException, exceptionObject, exception);
if (!exception) {
// Not a DOM Exception, try XPC Exception.
UNWRAP_OBJECT(Exception, exceptionObject, exception);
if (!exception) {
return nullptr;
}
}
nsCOMPtr<nsIStackFrame> stack = exception->GetLocation();
if (!stack) {
return nullptr;
}
JS::RootedValue value(rcx);
stack->GetNativeSavedFrame(&value);
if (value.isObject()) {
return &value.toObject();
}
return nullptr;
}
} /* namespace xpc */
static PRTime
GetCollectionTimeDelta()
{
PRTime now = PR_Now();
if (sFirstCollectionTime) {
return now - sFirstCollectionTime;
}
sFirstCollectionTime = now;
return 0;
}
static void
KillTimers()
{
nsJSContext::KillGCTimer();
nsJSContext::KillShrinkingGCTimer();
nsJSContext::KillCCRunner();
nsJSContext::KillICCRunner();
nsJSContext::KillFullGCTimer();
nsJSContext::KillInterSliceGCRunner();
}
// If we collected a substantial amount of cycles, poke the GC since more objects
// might be unreachable now.
static bool
NeedsGCAfterCC()
{
return sCCollectedWaitingForGC > 250 ||
sCCollectedZonesWaitingForGC > 0 ||
sLikelyShortLivingObjectsNeedingGC > 2500 ||
sNeedsGCAfterCC;
}
class nsJSEnvironmentObserver final : public nsIObserver
{
~nsJSEnvironmentObserver() {}
public:
NS_DECL_ISUPPORTS
NS_DECL_NSIOBSERVER
};
NS_IMPL_ISUPPORTS(nsJSEnvironmentObserver, nsIObserver)
NS_IMETHODIMP
nsJSEnvironmentObserver::Observe(nsISupports* aSubject, const char* aTopic,
const char16_t* aData)
{
if (!nsCRT::strcmp(aTopic, "memory-pressure")) {
if (sGCOnMemoryPressure) {
if(StringBeginsWith(nsDependentString(aData),
NS_LITERAL_STRING("low-memory-ongoing"))) {
// Don't GC/CC if we are in an ongoing low-memory state since its very
// slow and it likely won't help us anyway.
return NS_OK;
}
nsJSContext::GarbageCollectNow(JS::gcreason::MEM_PRESSURE,
nsJSContext::NonIncrementalGC,
nsJSContext::ShrinkingGC);
nsJSContext::CycleCollectNow();
if (NeedsGCAfterCC()) {
nsJSContext::GarbageCollectNow(JS::gcreason::MEM_PRESSURE,
nsJSContext::NonIncrementalGC,
nsJSContext::ShrinkingGC);
}
}
} else if (!nsCRT::strcmp(aTopic, "user-interaction-inactive")) {
if (sCompactOnUserInactive) {
nsJSContext::PokeShrinkingGC();
}
} else if (!nsCRT::strcmp(aTopic, "user-interaction-active")) {
nsJSContext::KillShrinkingGCTimer();
if (sIsCompactingOnUserInactive) {
AutoJSAPI jsapi;
jsapi.Init();
JS::AbortIncrementalGC(jsapi.cx());
}
MOZ_ASSERT(!sIsCompactingOnUserInactive);
} else if (!nsCRT::strcmp(aTopic, "quit-application") ||
!nsCRT::strcmp(aTopic, NS_XPCOM_SHUTDOWN_OBSERVER_ID)) {
sShuttingDown = true;
KillTimers();
}
return NS_OK;
}
/****************************************************************
************************** AutoFree ****************************
****************************************************************/
class AutoFree {
public:
explicit AutoFree(void* aPtr) : mPtr(aPtr) {
}
~AutoFree() {
if (mPtr)
free(mPtr);
}
void Invalidate() {
mPtr = 0;
}
private:
void *mPtr;
};
// A utility function for script languages to call. Although it looks small,
// the use of nsIDocShell and nsPresContext triggers a huge number of
// dependencies that most languages would not otherwise need.
// XXXmarkh - This function is mis-placed!
bool
NS_HandleScriptError(nsIScriptGlobalObject *aScriptGlobal,
const ErrorEventInit &aErrorEventInit,
nsEventStatus *aStatus)
{
bool called = false;
nsCOMPtr<nsPIDOMWindowInner> win(do_QueryInterface(aScriptGlobal));
nsIDocShell *docShell = win ? win->GetDocShell() : nullptr;
if (docShell) {
RefPtr<nsPresContext> presContext;
docShell->GetPresContext(getter_AddRefs(presContext));
static int32_t errorDepth; // Recursion prevention
++errorDepth;
if (errorDepth < 2) {
// Dispatch() must be synchronous for the recursion block
// (errorDepth) to work.
RefPtr<ErrorEvent> event =
ErrorEvent::Constructor(nsGlobalWindow::Cast(win),
NS_LITERAL_STRING("error"),
aErrorEventInit);
event->SetTrusted(true);
EventDispatcher::DispatchDOMEvent(win, nullptr, event, presContext,
aStatus);
called = true;
}
--errorDepth;
}
return called;
}
class ScriptErrorEvent : public Runnable
{
public:
ScriptErrorEvent(nsPIDOMWindowInner* aWindow,
JS::RootingContext* aRootingCx,
xpc::ErrorReport* aReport,
JS::Handle<JS::Value> aError)
: mozilla::Runnable("ScriptErrorEvent")
, mWindow(aWindow)
, mReport(aReport)
, mError(aRootingCx, aError)
{}
NS_IMETHOD Run() override
{
nsEventStatus status = nsEventStatus_eIgnore;
nsPIDOMWindowInner* win = mWindow;
MOZ_ASSERT(win);
MOZ_ASSERT(NS_IsMainThread());
// First, notify the DOM that we have a script error, but only if
// our window is still the current inner.
JS::RootingContext* rootingCx = RootingCx();
if (win->IsCurrentInnerWindow() && win->GetDocShell() && !sHandlingScriptError) {
AutoRestore<bool> recursionGuard(sHandlingScriptError);
sHandlingScriptError = true;
RefPtr<nsPresContext> presContext;
win->GetDocShell()->GetPresContext(getter_AddRefs(presContext));
RootedDictionary<ErrorEventInit> init(rootingCx);
init.mCancelable = true;
init.mFilename = mReport->mFileName;
init.mBubbles = true;
NS_NAMED_LITERAL_STRING(xoriginMsg, "Script error.");
if (!mReport->mIsMuted) {
init.mMessage = mReport->mErrorMsg;
init.mLineno = mReport->mLineNumber;
init.mColno = mReport->mColumn;
init.mError = mError;
} else {
NS_WARNING("Not same origin error!");
init.mMessage = xoriginMsg;
init.mLineno = 0;
}
RefPtr<ErrorEvent> event =
ErrorEvent::Constructor(nsGlobalWindow::Cast(win),
NS_LITERAL_STRING("error"), init);
event->SetTrusted(true);
EventDispatcher::DispatchDOMEvent(win, nullptr, event, presContext,
&status);
}
if (status != nsEventStatus_eConsumeNoDefault) {
JS::Rooted<JSObject*> stack(rootingCx,
xpc::FindExceptionStackForConsoleReport(win, mError));
mReport->LogToConsoleWithStack(stack);
}
return NS_OK;
}
private:
nsCOMPtr<nsPIDOMWindowInner> mWindow;
RefPtr<xpc::ErrorReport> mReport;
JS::PersistentRootedValue mError;
static bool sHandlingScriptError;
};
bool ScriptErrorEvent::sHandlingScriptError = false;
// This temporarily lives here to avoid code churn. It will go away entirely
// soon.
namespace xpc {
void
DispatchScriptErrorEvent(nsPIDOMWindowInner *win, JS::RootingContext* rootingCx,
xpc::ErrorReport *xpcReport, JS::Handle<JS::Value> exception)
{
nsContentUtils::AddScriptRunner(new ScriptErrorEvent(win, rootingCx, xpcReport, exception));
}
} /* namespace xpc */
#ifdef DEBUG
// A couple of useful functions to call when you're debugging.
nsGlobalWindow *
JSObject2Win(JSObject *obj)
{
return xpc::WindowOrNull(obj);
}
void
PrintWinURI(nsGlobalWindow *win)
{
if (!win) {
printf("No window passed in.\n");
return;
}
nsCOMPtr<nsIDocument> doc = win->GetExtantDoc();
if (!doc) {
printf("No document in the window.\n");
return;
}
nsIURI *uri = doc->GetDocumentURI();
if (!uri) {
printf("Document doesn't have a URI.\n");
return;
}
printf("%s\n", uri->GetSpecOrDefault().get());
}
void
PrintWinCodebase(nsGlobalWindow *win)
{
if (!win) {
printf("No window passed in.\n");
return;
}
nsIPrincipal *prin = win->GetPrincipal();
if (!prin) {
printf("Window doesn't have principals.\n");
return;
}
nsCOMPtr<nsIURI> uri;
prin->GetURI(getter_AddRefs(uri));
if (!uri) {
printf("No URI, maybe the system principal.\n");
return;
}
printf("%s\n", uri->GetSpecOrDefault().get());
}
void
DumpString(const nsAString &str)
{
printf("%s\n", NS_ConvertUTF16toUTF8(str).get());
}
#endif
#define JS_OPTIONS_DOT_STR "javascript.options."
nsJSContext::nsJSContext(bool aGCOnDestruction,
nsIScriptGlobalObject* aGlobalObject)
: mWindowProxy(nullptr)
, mGCOnDestruction(aGCOnDestruction)
, mGlobalObjectRef(aGlobalObject)
{
EnsureStatics();
mIsInitialized = false;
mProcessingScriptTag = false;
HoldJSObjects(this);
}
nsJSContext::~nsJSContext()
{
mGlobalObjectRef = nullptr;
Destroy();
}
void
nsJSContext::Destroy()
{
if (mGCOnDestruction) {
PokeGC(JS::gcreason::NSJSCONTEXT_DESTROY, mWindowProxy);
}
DropJSObjects(this);
}
// QueryInterface implementation for nsJSContext
NS_IMPL_CYCLE_COLLECTION_CLASS(nsJSContext)
NS_IMPL_CYCLE_COLLECTION_TRACE_BEGIN(nsJSContext)
NS_IMPL_CYCLE_COLLECTION_TRACE_JS_MEMBER_CALLBACK(mWindowProxy)
NS_IMPL_CYCLE_COLLECTION_TRACE_END
NS_IMPL_CYCLE_COLLECTION_UNLINK_BEGIN(nsJSContext)
tmp->mIsInitialized = false;
tmp->mGCOnDestruction = false;
tmp->mWindowProxy = nullptr;
tmp->Destroy();
NS_IMPL_CYCLE_COLLECTION_UNLINK(mGlobalObjectRef)
NS_IMPL_CYCLE_COLLECTION_UNLINK_END
NS_IMPL_CYCLE_COLLECTION_TRAVERSE_BEGIN(nsJSContext)
NS_IMPL_CYCLE_COLLECTION_TRAVERSE(mGlobalObjectRef)
NS_IMPL_CYCLE_COLLECTION_TRAVERSE_END
NS_INTERFACE_MAP_BEGIN_CYCLE_COLLECTION(nsJSContext)
NS_INTERFACE_MAP_ENTRY(nsIScriptContext)
NS_INTERFACE_MAP_ENTRY(nsISupports)
NS_INTERFACE_MAP_END
NS_IMPL_CYCLE_COLLECTING_ADDREF(nsJSContext)
NS_IMPL_CYCLE_COLLECTING_RELEASE(nsJSContext)
#ifdef DEBUG
bool
AtomIsEventHandlerName(nsAtom *aName)
{
const char16_t *name = aName->GetUTF16String();
const char16_t *cp;
char16_t c;
for (cp = name; *cp != '\0'; ++cp)
{
c = *cp;
if ((c < 'A' || c > 'Z') && (c < 'a' || c > 'z'))
return false;
}
return true;
}
#endif
nsIScriptGlobalObject *
nsJSContext::GetGlobalObject()
{
// Note: this could probably be simplified somewhat more; see bug 974327
// comments 1 and 3.
if (!mWindowProxy) {
return nullptr;
}
MOZ_ASSERT(mGlobalObjectRef);
return mGlobalObjectRef;
}
nsresult
nsJSContext::InitContext()
{
// Make sure callers of this use
// WillInitializeContext/DidInitializeContext around this call.
NS_ENSURE_TRUE(!mIsInitialized, NS_ERROR_ALREADY_INITIALIZED);
// XXXbz Is there still a point to this function?
return NS_OK;
}
nsresult
nsJSContext::SetProperty(JS::Handle<JSObject*> aTarget, const char* aPropName, nsISupports* aArgs)
{
AutoJSAPI jsapi;
if (NS_WARN_IF(!jsapi.Init(GetGlobalObject()))) {
return NS_ERROR_FAILURE;
}
JSContext* cx = jsapi.cx();
JS::AutoValueVector args(cx);
JS::Rooted<JSObject*> global(cx, GetWindowProxy());
nsresult rv =
ConvertSupportsTojsvals(aArgs, global, args);
NS_ENSURE_SUCCESS(rv, rv);
// got the arguments, now attach them.
for (uint32_t i = 0; i < args.length(); ++i) {
if (!JS_WrapValue(cx, args[i])) {
return NS_ERROR_FAILURE;
}
}
JS::Rooted<JSObject*> array(cx, ::JS_NewArrayObject(cx, args));
if (!array) {
return NS_ERROR_FAILURE;
}
return JS_DefineProperty(cx, aTarget, aPropName, array, 0) ? NS_OK : NS_ERROR_FAILURE;
}
nsresult
nsJSContext::ConvertSupportsTojsvals(nsISupports* aArgs,
JS::Handle<JSObject*> aScope,
JS::AutoValueVector& aArgsOut)
{
nsresult rv = NS_OK;
// If the array implements nsIJSArgArray, copy the contents and return.
nsCOMPtr<nsIJSArgArray> fastArray = do_QueryInterface(aArgs);
if (fastArray) {
uint32_t argc;
JS::Value* argv;
rv = fastArray->GetArgs(&argc, reinterpret_cast<void **>(&argv));
if (NS_SUCCEEDED(rv) && !aArgsOut.append(argv, argc)) {
rv = NS_ERROR_OUT_OF_MEMORY;
}
return rv;
}
// Take the slower path converting each item.
// Handle only nsIArray and nsIVariant. nsIArray is only needed for
// SetProperty('arguments', ...);
nsIXPConnect *xpc = nsContentUtils::XPConnect();
NS_ENSURE_TRUE(xpc, NS_ERROR_UNEXPECTED);
AutoJSContext cx;
if (!aArgs)
return NS_OK;
uint32_t argCount;
// This general purpose function may need to convert an arg array
// (window.arguments, event-handler args) and a generic property.
nsCOMPtr<nsIArray> argsArray(do_QueryInterface(aArgs));
if (argsArray) {
rv = argsArray->GetLength(&argCount);
NS_ENSURE_SUCCESS(rv, rv);
if (argCount == 0)
return NS_OK;
} else {
argCount = 1; // the nsISupports which is not an array
}
// Use the caller's auto guards to release and unroot.
if (!aArgsOut.resize(argCount)) {
return NS_ERROR_OUT_OF_MEMORY;
}
if (argsArray) {
for (uint32_t argCtr = 0; argCtr < argCount && NS_SUCCEEDED(rv); argCtr++) {
nsCOMPtr<nsISupports> arg;
JS::MutableHandle<JS::Value> thisVal = aArgsOut[argCtr];
argsArray->QueryElementAt(argCtr, NS_GET_IID(nsISupports),
getter_AddRefs(arg));
if (!arg) {
thisVal.setNull();
continue;
}
nsCOMPtr<nsIVariant> variant(do_QueryInterface(arg));
if (variant != nullptr) {
rv = xpc->VariantToJS(cx, aScope, variant, thisVal);
} else {
// And finally, support the nsISupportsPrimitives supplied
// by the AppShell. It generally will pass only strings, but
// as we have code for handling all, we may as well use it.
rv = AddSupportsPrimitiveTojsvals(arg, thisVal.address());
if (rv == NS_ERROR_NO_INTERFACE) {
// something else - probably an event object or similar -
// just wrap it.
#ifdef DEBUG
// but first, check its not another nsISupportsPrimitive, as
// these are now deprecated for use with script contexts.
nsCOMPtr<nsISupportsPrimitive> prim(do_QueryInterface(arg));
NS_ASSERTION(prim == nullptr,
"Don't pass nsISupportsPrimitives - use nsIVariant!");
#endif
JSAutoCompartment ac(cx, aScope);
rv = nsContentUtils::WrapNative(cx, arg, thisVal);
}
}
}
} else {
nsCOMPtr<nsIVariant> variant = do_QueryInterface(aArgs);
if (variant) {
rv = xpc->VariantToJS(cx, aScope, variant, aArgsOut[0]);
} else {
NS_ERROR("Not an array, not an interface?");
rv = NS_ERROR_UNEXPECTED;
}
}
return rv;
}
// This really should go into xpconnect somewhere...
nsresult
nsJSContext::AddSupportsPrimitiveTojsvals(nsISupports *aArg, JS::Value *aArgv)
{
NS_PRECONDITION(aArg, "Empty arg");
nsCOMPtr<nsISupportsPrimitive> argPrimitive(do_QueryInterface(aArg));
if (!argPrimitive)
return NS_ERROR_NO_INTERFACE;
AutoJSContext cx;
uint16_t type;
argPrimitive->GetType(&type);
switch(type) {
case nsISupportsPrimitive::TYPE_CSTRING : {
nsCOMPtr<nsISupportsCString> p(do_QueryInterface(argPrimitive));
NS_ENSURE_TRUE(p, NS_ERROR_UNEXPECTED);
nsAutoCString data;
p->GetData(data);
JSString *str = ::JS_NewStringCopyN(cx, data.get(), data.Length());
NS_ENSURE_TRUE(str, NS_ERROR_OUT_OF_MEMORY);
aArgv->setString(str);
break;
}
case nsISupportsPrimitive::TYPE_STRING : {
nsCOMPtr<nsISupportsString> p(do_QueryInterface(argPrimitive));
NS_ENSURE_TRUE(p, NS_ERROR_UNEXPECTED);
nsAutoString data;
p->GetData(data);
// cast is probably safe since wchar_t and char16_t are expected
// to be equivalent; both unsigned 16-bit entities
JSString *str =
::JS_NewUCStringCopyN(cx, data.get(), data.Length());
NS_ENSURE_TRUE(str, NS_ERROR_OUT_OF_MEMORY);
aArgv->setString(str);
break;
}
case nsISupportsPrimitive::TYPE_PRBOOL : {
nsCOMPtr<nsISupportsPRBool> p(do_QueryInterface(argPrimitive));
NS_ENSURE_TRUE(p, NS_ERROR_UNEXPECTED);
bool data;
p->GetData(&data);
aArgv->setBoolean(data);
break;
}
case nsISupportsPrimitive::TYPE_PRUINT8 : {
nsCOMPtr<nsISupportsPRUint8> p(do_QueryInterface(argPrimitive));
NS_ENSURE_TRUE(p, NS_ERROR_UNEXPECTED);
uint8_t data;
p->GetData(&data);
aArgv->setInt32(data);
break;
}
case nsISupportsPrimitive::TYPE_PRUINT16 : {
nsCOMPtr<nsISupportsPRUint16> p(do_QueryInterface(argPrimitive));
NS_ENSURE_TRUE(p, NS_ERROR_UNEXPECTED);
uint16_t data;
p->GetData(&data);
aArgv->setInt32(data);
break;
}
case nsISupportsPrimitive::TYPE_PRUINT32 : {
nsCOMPtr<nsISupportsPRUint32> p(do_QueryInterface(argPrimitive));
NS_ENSURE_TRUE(p, NS_ERROR_UNEXPECTED);
uint32_t data;
p->GetData(&data);
aArgv->setInt32(data);
break;
}
case nsISupportsPrimitive::TYPE_CHAR : {
nsCOMPtr<nsISupportsChar> p(do_QueryInterface(argPrimitive));
NS_ENSURE_TRUE(p, NS_ERROR_UNEXPECTED);
char data;
p->GetData(&data);
JSString *str = ::JS_NewStringCopyN(cx, &data, 1);
NS_ENSURE_TRUE(str, NS_ERROR_OUT_OF_MEMORY);
aArgv->setString(str);
break;
}
case nsISupportsPrimitive::TYPE_PRINT16 : {
nsCOMPtr<nsISupportsPRInt16> p(do_QueryInterface(argPrimitive));
NS_ENSURE_TRUE(p, NS_ERROR_UNEXPECTED);
int16_t data;
p->GetData(&data);
aArgv->setInt32(data);
break;
}
case nsISupportsPrimitive::TYPE_PRINT32 : {
nsCOMPtr<nsISupportsPRInt32> p(do_QueryInterface(argPrimitive));
NS_ENSURE_TRUE(p, NS_ERROR_UNEXPECTED);
int32_t data;
p->GetData(&data);
aArgv->setInt32(data);
break;
}
case nsISupportsPrimitive::TYPE_FLOAT : {
nsCOMPtr<nsISupportsFloat> p(do_QueryInterface(argPrimitive));
NS_ENSURE_TRUE(p, NS_ERROR_UNEXPECTED);
float data;
p->GetData(&data);
*aArgv = ::JS_NumberValue(data);
break;
}
case nsISupportsPrimitive::TYPE_DOUBLE : {
nsCOMPtr<nsISupportsDouble> p(do_QueryInterface(argPrimitive));
NS_ENSURE_TRUE(p, NS_ERROR_UNEXPECTED);
double data;
p->GetData(&data);
*aArgv = ::JS_NumberValue(data);
break;
}
case nsISupportsPrimitive::TYPE_INTERFACE_POINTER : {
nsCOMPtr<nsISupportsInterfacePointer> p(do_QueryInterface(argPrimitive));
NS_ENSURE_TRUE(p, NS_ERROR_UNEXPECTED);
nsCOMPtr<nsISupports> data;
nsIID *iid = nullptr;
p->GetData(getter_AddRefs(data));
p->GetDataIID(&iid);
NS_ENSURE_TRUE(iid, NS_ERROR_UNEXPECTED);
AutoFree iidGuard(iid); // Free iid upon destruction.
JS::Rooted<JSObject*> scope(cx, GetWindowProxy());
JS::Rooted<JS::Value> v(cx);
JSAutoCompartment ac(cx, scope);
nsresult rv = nsContentUtils::WrapNative(cx, data, iid, &v);
NS_ENSURE_SUCCESS(rv, rv);
*aArgv = v;
break;
}
case nsISupportsPrimitive::TYPE_ID :
case nsISupportsPrimitive::TYPE_PRUINT64 :
case nsISupportsPrimitive::TYPE_PRINT64 :
case nsISupportsPrimitive::TYPE_PRTIME : {
NS_WARNING("Unsupported primitive type used");
aArgv->setNull();
break;
}
default : {
NS_WARNING("Unknown primitive type used");
aArgv->setNull();
break;
}
}
return NS_OK;
}
#ifdef MOZ_JPROF
#include <signal.h>
inline bool
IsJProfAction(struct sigaction *action)
{
return (action->sa_sigaction &&
(action->sa_flags & (SA_RESTART | SA_SIGINFO)) == (SA_RESTART | SA_SIGINFO));
}
void NS_JProfStartProfiling();
void NS_JProfStopProfiling();
void NS_JProfClearCircular();
static bool
JProfStartProfilingJS(JSContext *cx, unsigned argc, JS::Value *vp)
{
NS_JProfStartProfiling();
return true;
}
void NS_JProfStartProfiling()
{
// Figure out whether we're dealing with SIGPROF, SIGALRM, or
// SIGPOLL profiling (SIGALRM for JP_REALTIME, SIGPOLL for
// JP_RTC_HZ)
struct sigaction action;
// Must check ALRM before PROF since both are enabled for real-time
sigaction(SIGALRM, nullptr, &action);
//printf("SIGALRM: %p, flags = %x\n",action.sa_sigaction,action.sa_flags);
if (IsJProfAction(&action)) {
//printf("Beginning real-time jprof profiling.\n");
raise(SIGALRM);
return;
}
sigaction(SIGPROF, nullptr, &action);
//printf("SIGPROF: %p, flags = %x\n",action.sa_sigaction,action.sa_flags);
if (IsJProfAction(&action)) {
//printf("Beginning process-time jprof profiling.\n");
raise(SIGPROF);
return;
}
sigaction(SIGPOLL, nullptr, &action);
//printf("SIGPOLL: %p, flags = %x\n",action.sa_sigaction,action.sa_flags);
if (IsJProfAction(&action)) {
//printf("Beginning rtc-based jprof profiling.\n");
raise(SIGPOLL);
return;
}
printf("Could not start jprof-profiling since JPROF_FLAGS was not set.\n");
}
static bool
JProfStopProfilingJS(JSContext *cx, unsigned argc, JS::Value *vp)
{
NS_JProfStopProfiling();
return true;
}
void
NS_JProfStopProfiling()
{
raise(SIGUSR1);
//printf("Stopped jprof profiling.\n");
}
static bool
JProfClearCircularJS(JSContext *cx, unsigned argc, JS::Value *vp)
{
NS_JProfClearCircular();
return true;
}
void
NS_JProfClearCircular()
{
raise(SIGUSR2);
//printf("cleared jprof buffer\n");
}
static bool
JProfSaveCircularJS(JSContext *cx, unsigned argc, JS::Value *vp)
{
// Not ideal...
NS_JProfStopProfiling();
NS_JProfStartProfiling();
return true;
}
static const JSFunctionSpec JProfFunctions[] = {
JS_FN("JProfStartProfiling", JProfStartProfilingJS, 0, 0),
JS_FN("JProfStopProfiling", JProfStopProfilingJS, 0, 0),
JS_FN("JProfClearCircular", JProfClearCircularJS, 0, 0),
JS_FN("JProfSaveCircular", JProfSaveCircularJS, 0, 0),
JS_FS_END
};
#endif /* defined(MOZ_JPROF) */
nsresult
nsJSContext::InitClasses(JS::Handle<JSObject*> aGlobalObj)
{
AutoJSAPI jsapi;
jsapi.Init();
JSContext* cx = jsapi.cx();
JSAutoCompartment ac(cx, aGlobalObj);
// Attempt to initialize profiling functions
::JS_DefineProfilingFunctions(cx, aGlobalObj);
#ifdef MOZ_JPROF
// Attempt to initialize JProf functions
::JS_DefineFunctions(cx, aGlobalObj, JProfFunctions);
#endif
return NS_OK;
}
void
nsJSContext::WillInitializeContext()
{
mIsInitialized = false;
}
void
nsJSContext::DidInitializeContext()
{
mIsInitialized = true;
}
bool
nsJSContext::IsContextInitialized()
{
return mIsInitialized;
}
bool
nsJSContext::GetProcessingScriptTag()
{
return mProcessingScriptTag;
}
void
nsJSContext::SetProcessingScriptTag(bool aFlag)
{
mProcessingScriptTag = aFlag;
}
void
FullGCTimerFired(nsITimer* aTimer, void* aClosure)
{
nsJSContext::KillFullGCTimer();
MOZ_ASSERT(!aClosure, "Don't pass a closure to FullGCTimerFired");
nsJSContext::GarbageCollectNow(JS::gcreason::FULL_GC_TIMER,
nsJSContext::IncrementalGC);
}
//static
void
nsJSContext::GarbageCollectNow(JS::gcreason::Reason aReason,
IsIncremental aIncremental,
IsShrinking aShrinking,
int64_t aSliceMillis)
{
AUTO_PROFILER_LABEL_DYNAMIC("nsJSContext::GarbageCollectNow", GC,
JS::gcreason::ExplainReason(aReason));
MOZ_ASSERT_IF(aSliceMillis, aIncremental == IncrementalGC);
KillGCTimer();
// Reset sPendingLoadCount in case the timer that fired was a
// timer we scheduled due to a normal GC timer firing while
// documents were loading. If this happens we're waiting for a
// document that is taking a long time to load, and we effectively
// ignore the fact that the currently loading documents are still
// loading and move on as if they weren't.
sPendingLoadCount = 0;
sLoadingInProgress = false;
// We use danger::GetJSContext() since AutoJSAPI will assert if the current
// thread's context is null (such as during shutdown).
JSContext* cx = danger::GetJSContext();
if (!nsContentUtils::XPConnect() || !cx) {
return;
}
if (sCCLockedOut && aIncremental == IncrementalGC) {
// We're in the middle of incremental GC. Do another slice.
JS::PrepareForIncrementalGC(cx);
JS::IncrementalGCSlice(cx, aReason, aSliceMillis);
return;
}
JSGCInvocationKind gckind = aShrinking == ShrinkingGC ? GC_SHRINK : GC_NORMAL;
if (aIncremental == NonIncrementalGC || aReason == JS::gcreason::FULL_GC_TIMER) {
sNeedsFullGC = true;
}
if (sNeedsFullGC) {
JS::PrepareForFullGC(cx);
} else {
CycleCollectedJSRuntime::Get()->PrepareWaitingZonesForGC();
}
if (aIncremental == IncrementalGC) {
JS::StartIncrementalGC(cx, gckind, aReason, aSliceMillis);
} else {
JS::GCForReason(cx, gckind, aReason);
}
}
static void
FinishAnyIncrementalGC()
{
AUTO_PROFILER_LABEL("FinishAnyIncrementalGC", GC);
if (sCCLockedOut) {
AutoJSAPI jsapi;
jsapi.Init();
// We're in the middle of an incremental GC, so finish it.
JS::PrepareForIncrementalGC(jsapi.cx());
JS::FinishIncrementalGC(jsapi.cx(), JS::gcreason::CC_FORCED);
}
}
static void
FireForgetSkippable(uint32_t aSuspected, bool aRemoveChildless,
TimeStamp aDeadline)
{
AUTO_PROFILER_TRACING("CC", aDeadline.IsNull() ? "ForgetSkippable"
: "IdleForgetSkippable");
PRTime startTime = PR_Now();
TimeStamp startTimeStamp = TimeStamp::Now();
FinishAnyIncrementalGC();
bool earlyForgetSkippable =
sCleanupsSinceLastGC < NS_MAJOR_FORGET_SKIPPABLE_CALLS;
int64_t budgetMs = aDeadline.IsNull() ?
kForgetSkippableSliceDuration :
int64_t((aDeadline - TimeStamp::Now()).ToMilliseconds());
js::SliceBudget budget = js::SliceBudget(js::TimeBudget(budgetMs));
nsCycleCollector_forgetSkippable(budget, aRemoveChildless, earlyForgetSkippable);
sPreviousSuspectedCount = nsCycleCollector_suspectedCount();
++sCleanupsSinceLastGC;
PRTime delta = PR_Now() - startTime;
if (sMinForgetSkippableTime > delta) {
sMinForgetSkippableTime = delta;
}
if (sMaxForgetSkippableTime < delta) {
sMaxForgetSkippableTime = delta;
}
sTotalForgetSkippableTime += delta;
sRemovedPurples += (aSuspected - sPreviousSuspectedCount);
++sForgetSkippableBeforeCC;
TimeStamp now = TimeStamp::Now();
TimeDuration duration = now - startTimeStamp;
if (duration.ToSeconds()) {
TimeDuration idleDuration;
if (!aDeadline.IsNull()) {
if (aDeadline < now) {
// This slice overflowed the idle period.
idleDuration = aDeadline - startTimeStamp;
} else {
idleDuration = duration;
}
}
uint32_t percent =
uint32_t(idleDuration.ToSeconds() / duration.ToSeconds() * 100);
Telemetry::Accumulate(Telemetry::FORGET_SKIPPABLE_DURING_IDLE, percent);
}
}
MOZ_ALWAYS_INLINE
static uint32_t
TimeBetween(TimeStamp start, TimeStamp end)
{
MOZ_ASSERT(end >= start);
return (uint32_t) ((end - start).ToMilliseconds());
}
static uint32_t
TimeUntilNow(TimeStamp start)
{
if (start.IsNull()) {
return 0;
}
return TimeBetween(start, TimeStamp::Now());
}
struct CycleCollectorStats
{
constexpr CycleCollectorStats() :
mMaxGCDuration(0), mRanSyncForgetSkippable(false), mSuspected(0),
mMaxSkippableDuration(0), mMaxSliceTime(0), mMaxSliceTimeSinceClear(0),
mTotalSliceTime(0), mAnyLockedOut(false), mFile(nullptr)
{}
void Init()
{
Clear();
mMaxSliceTimeSinceClear = 0;
char* env = getenv("MOZ_CCTIMER");
if (!env) {
return;
}
if (strcmp(env, "none") == 0) {
mFile = nullptr;
} else if (strcmp(env, "stdout") == 0) {
mFile = stdout;
} else if (strcmp(env, "stderr") == 0) {
mFile = stderr;
} else {
mFile = fopen(env, "a");
if (!mFile) {
MOZ_CRASH("Failed to open MOZ_CCTIMER log file.");
}
}
}
void Clear()
{
if (mFile && mFile != stdout && mFile != stderr) {
fclose(mFile);
}
mBeginSliceTime = TimeStamp();
mEndSliceTime = TimeStamp();
mBeginTime = TimeStamp();
mMaxGCDuration = 0;
mRanSyncForgetSkippable = false;
mSuspected = 0;
mMaxSkippableDuration = 0;
mMaxSliceTime = 0;
mTotalSliceTime = 0;
mAnyLockedOut = false;
}
void PrepareForCycleCollectionSlice(TimeStamp aDeadline = TimeStamp());
void FinishCycleCollectionSlice()
{
if (mBeginSliceTime.IsNull()) {
// We already called this method from EndCycleCollectionCallback for this slice.
return;
}
mEndSliceTime = TimeStamp::Now();
TimeDuration duration = mEndSliceTime - mBeginSliceTime;
if (duration.ToSeconds()) {
TimeDuration idleDuration;
if (!mIdleDeadline.IsNull()) {
if (mIdleDeadline < mEndSliceTime) {
// This slice overflowed the idle period.
idleDuration = mIdleDeadline - mBeginSliceTime;
} else {
idleDuration = duration;
}
}
uint32_t percent =
uint32_t(idleDuration.ToSeconds() / duration.ToSeconds() * 100);
Telemetry::Accumulate(Telemetry::CYCLE_COLLECTOR_SLICE_DURING_IDLE,
percent);
}
uint32_t sliceTime = TimeBetween(mBeginSliceTime, mEndSliceTime);
mMaxSliceTime = std::max(mMaxSliceTime, sliceTime);
mMaxSliceTimeSinceClear = std::max(mMaxSliceTimeSinceClear, sliceTime);
mTotalSliceTime += sliceTime;
mBeginSliceTime = TimeStamp();
}
void RunForgetSkippable();
// Time the current slice began, including any GC finishing.
TimeStamp mBeginSliceTime;
// Time the previous slice of the current CC ended.
TimeStamp mEndSliceTime;
// Time the current cycle collection began.
TimeStamp mBeginTime;
// The longest GC finishing duration for any slice of the current CC.
uint32_t mMaxGCDuration;
// True if we ran sync forget skippable in any slice of the current CC.
bool mRanSyncForgetSkippable;
// Number of suspected objects at the start of the current CC.
uint32_t mSuspected;
// The longest duration spent on sync forget skippable in any slice of the
// current CC.
uint32_t mMaxSkippableDuration;
// The longest pause of any slice in the current CC.
uint32_t mMaxSliceTime;
// The longest slice time since ClearMaxCCSliceTime() was called.
uint32_t mMaxSliceTimeSinceClear;
// The total amount of time spent actually running the current CC.
uint32_t mTotalSliceTime;
// True if we were locked out by the GC in any slice of the current CC.
bool mAnyLockedOut;
// A file to dump CC activity to; set by MOZ_CCTIMER environment variable.
FILE* mFile;
// In case CC slice was triggered during idle time, set to the end of the idle
// period.
TimeStamp mIdleDeadline;
};
CycleCollectorStats gCCStats;
void
CycleCollectorStats::PrepareForCycleCollectionSlice(TimeStamp aDeadline)
{
mBeginSliceTime = TimeStamp::Now();
mIdleDeadline = aDeadline;
// Before we begin the cycle collection, make sure there is no active GC.
if (sCCLockedOut) {
mAnyLockedOut = true;
FinishAnyIncrementalGC();
uint32_t gcTime = TimeBetween(mBeginSliceTime, TimeStamp::Now());
mMaxGCDuration = std::max(mMaxGCDuration, gcTime);
}
}
void
CycleCollectorStats::RunForgetSkippable()
{
// Run forgetSkippable synchronously to reduce the size of the CC graph. This
// is particularly useful if we recently finished a GC.
TimeStamp beginForgetSkippable = TimeStamp::Now();
bool ranSyncForgetSkippable = false;
while (sCleanupsSinceLastGC < NS_MAJOR_FORGET_SKIPPABLE_CALLS) {
FireForgetSkippable(nsCycleCollector_suspectedCount(), false, TimeStamp());
ranSyncForgetSkippable = true;
}
if (ranSyncForgetSkippable) {
mMaxSkippableDuration =
std::max(mMaxSkippableDuration, TimeUntilNow(beginForgetSkippable));
mRanSyncForgetSkippable = true;
}
}
//static
void
nsJSContext::CycleCollectNow(nsICycleCollectorListener *aListener)
{
if (!NS_IsMainThread()) {
return;
}
AUTO_PROFILER_LABEL("nsJSContext::CycleCollectNow", CC);
gCCStats.PrepareForCycleCollectionSlice(TimeStamp());
nsCycleCollector_collect(aListener);
gCCStats.FinishCycleCollectionSlice();
}
//static
void
nsJSContext::RunCycleCollectorSlice(TimeStamp aDeadline)
{
if (!NS_IsMainThread()) {
return;
}
AUTO_PROFILER_TRACING("CC", aDeadline.IsNull() ? "CCSlice" : "IdleCCSlice");
AUTO_PROFILER_LABEL("nsJSContext::RunCycleCollectorSlice", CC);
gCCStats.PrepareForCycleCollectionSlice(aDeadline);
// Decide how long we want to budget for this slice. By default,
// use an unlimited budget.
js::SliceBudget budget = js::SliceBudget::unlimited();
if (sIncrementalCC) {
int64_t baseBudget = kICCSliceBudget;
if (!aDeadline.IsNull()) {
baseBudget = int64_t((aDeadline - TimeStamp::Now()).ToMilliseconds());
}
if (gCCStats.mBeginTime.IsNull()) {
// If no CC is in progress, use the standard slice time.
budget = js::SliceBudget(js::TimeBudget(baseBudget));
} else {
TimeStamp now = TimeStamp::Now();
// Only run a limited slice if we're within the max running time.
uint32_t runningTime = TimeBetween(gCCStats.mBeginTime, now);
if (runningTime < kMaxICCDuration) {
const float maxSlice = MainThreadIdlePeriod::GetLongIdlePeriod();
// Try to make up for a delay in running this slice.
float sliceDelayMultiplier =
TimeBetween(gCCStats.mEndSliceTime, now) / (float)kICCIntersliceDelay;
float delaySliceBudget =
std::min(baseBudget * sliceDelayMultiplier, maxSlice);
// Increase slice budgets up to |maxSlice| as we approach
// half way through the ICC, to avoid large sync CCs.
float percentToHalfDone = std::min(2.0f * runningTime / kMaxICCDuration, 1.0f);
float laterSliceBudget = maxSlice * percentToHalfDone;
budget = js::SliceBudget(js::TimeBudget(std::max({delaySliceBudget,
laterSliceBudget, (float)baseBudget})));
}
}
}
nsCycleCollector_collectSlice(budget,
aDeadline.IsNull() ||
(aDeadline - TimeStamp::Now()).ToMilliseconds() <
kICCSliceBudget);
gCCStats.FinishCycleCollectionSlice();
}
//static
void
nsJSContext::RunCycleCollectorWorkSlice(int64_t aWorkBudget)
{
if (!NS_IsMainThread()) {
return;
}
AUTO_PROFILER_LABEL("nsJSContext::RunCycleCollectorWorkSlice", CC);
gCCStats.PrepareForCycleCollectionSlice();
js::SliceBudget budget = js::SliceBudget(js::WorkBudget(aWorkBudget));
nsCycleCollector_collectSlice(budget);
gCCStats.FinishCycleCollectionSlice();
}
void
nsJSContext::ClearMaxCCSliceTime()
{
gCCStats.mMaxSliceTimeSinceClear = 0;
}
uint32_t
nsJSContext::GetMaxCCSliceTimeSinceClear()
{
return gCCStats.mMaxSliceTimeSinceClear;
}
static bool
ICCRunnerFired(TimeStamp aDeadline)
{
if (sDidShutdown) {
return false;
}
// Ignore ICC timer fires during IGC. Running ICC during an IGC will cause us
// to synchronously finish the GC, which is bad.
if (sCCLockedOut) {
PRTime now = PR_Now();
if (sCCLockedOutTime == 0) {
sCCLockedOutTime = now;
return false;
}
if (now - sCCLockedOutTime < NS_MAX_CC_LOCKEDOUT_TIME) {
return false;
}
}
nsJSContext::RunCycleCollectorSlice(aDeadline);
return true;
}
//static
void
nsJSContext::BeginCycleCollectionCallback()
{
MOZ_ASSERT(NS_IsMainThread());
gCCStats.mBeginTime = gCCStats.mBeginSliceTime.IsNull() ? TimeStamp::Now() : gCCStats.mBeginSliceTime;
gCCStats.mSuspected = nsCycleCollector_suspectedCount();
KillCCRunner();
gCCStats.RunForgetSkippable();
MOZ_ASSERT(!sICCRunner, "Tried to create a new ICC timer when one already existed.");
// Create an ICC timer even if ICC is globally disabled, because we could be manually triggering
// an incremental collection, and we want to be sure to finish it.
sICCRunner = IdleTaskRunner::Create(ICCRunnerFired,
"BeginCycleCollectionCallback::ICCRunnerFired",
kICCIntersliceDelay,
kIdleICCSliceBudget,
true,
[]{ return sShuttingDown; },
TaskCategory::GarbageCollection);
}
static_assert(NS_GC_DELAY > kMaxICCDuration, "A max duration ICC shouldn't reduce GC delay to 0");
//static
void
nsJSContext::EndCycleCollectionCallback(CycleCollectorResults &aResults)
{
MOZ_ASSERT(NS_IsMainThread());
nsJSContext::KillICCRunner();
// Update timing information for the current slice before we log it, if
// we previously called PrepareForCycleCollectionSlice(). During shutdown
// CCs, this won't happen.
gCCStats.FinishCycleCollectionSlice();
sCCollectedWaitingForGC += aResults.mFreedGCed;
sCCollectedZonesWaitingForGC += aResults.mFreedJSZones;
TimeStamp endCCTimeStamp = TimeStamp::Now();
uint32_t ccNowDuration = TimeBetween(gCCStats.mBeginTime, endCCTimeStamp);
if (NeedsGCAfterCC()) {
PokeGC(JS::gcreason::CC_WAITING, nullptr,
NS_GC_DELAY - std::min(ccNowDuration, kMaxICCDuration));
}
// Log information about the CC via telemetry, JSON and the console.
Telemetry::Accumulate(Telemetry::CYCLE_COLLECTOR_FINISH_IGC, gCCStats.mAnyLockedOut);
Telemetry::Accumulate(Telemetry::CYCLE_COLLECTOR_SYNC_SKIPPABLE, gCCStats.mRanSyncForgetSkippable);
Telemetry::Accumulate(Telemetry::CYCLE_COLLECTOR_FULL, ccNowDuration);
Telemetry::Accumulate(Telemetry::CYCLE_COLLECTOR_MAX_PAUSE, gCCStats.mMaxSliceTime);
if (!sLastCCEndTime.IsNull()) {
// TimeBetween returns milliseconds, but we want to report seconds.
uint32_t timeBetween = TimeBetween(sLastCCEndTime, gCCStats.mBeginTime) / 1000;
Telemetry::Accumulate(Telemetry::CYCLE_COLLECTOR_TIME_BETWEEN, timeBetween);
}
sLastCCEndTime = endCCTimeStamp;
Telemetry::Accumulate(Telemetry::FORGET_SKIPPABLE_MAX,
sMaxForgetSkippableTime / PR_USEC_PER_MSEC);
PRTime delta = GetCollectionTimeDelta();
uint32_t cleanups = sForgetSkippableBeforeCC ? sForgetSkippableBeforeCC : 1;
uint32_t minForgetSkippableTime = (sMinForgetSkippableTime == UINT32_MAX)
? 0 : sMinForgetSkippableTime;
if (sPostGCEventsToConsole || gCCStats.mFile) {
nsCString mergeMsg;
if (aResults.mMergedZones) {
mergeMsg.AssignLiteral(" merged");
}
nsCString gcMsg;
if (aResults.mForcedGC) {
gcMsg.AssignLiteral(", forced a GC");
}
const char16_t *kFmt =
u"CC(T+%.1f)[%s-%i] max pause: %lums, total time: %lums, slices: %lu, suspected: %lu, visited: %lu RCed and %lu%s GCed, collected: %lu RCed and %lu GCed (%lu|%lu|%lu waiting for GC)%s\n"
u"ForgetSkippable %lu times before CC, min: %lu ms, max: %lu ms, avg: %lu ms, total: %lu ms, max sync: %lu ms, removed: %lu";
nsString msg;
nsTextFormatter::ssprintf(msg, kFmt, double(delta) / PR_USEC_PER_SEC,
ProcessNameForCollectorLog(), getpid(),
gCCStats.mMaxSliceTime, gCCStats.mTotalSliceTime,
aResults.mNumSlices, gCCStats.mSuspected,
aResults.mVisitedRefCounted, aResults.mVisitedGCed, mergeMsg.get(),
aResults.mFreedRefCounted, aResults.mFreedGCed,
sCCollectedWaitingForGC, sCCollectedZonesWaitingForGC, sLikelyShortLivingObjectsNeedingGC,
gcMsg.get(),
sForgetSkippableBeforeCC,
minForgetSkippableTime / PR_USEC_PER_MSEC,
sMaxForgetSkippableTime / PR_USEC_PER_MSEC,
(sTotalForgetSkippableTime / cleanups) /
PR_USEC_PER_MSEC,
sTotalForgetSkippableTime / PR_USEC_PER_MSEC,
gCCStats.mMaxSkippableDuration, sRemovedPurples);
if (sPostGCEventsToConsole) {
nsCOMPtr<nsIConsoleService> cs =
do_GetService(NS_CONSOLESERVICE_CONTRACTID);
if (cs) {
cs->LogStringMessage(msg.get());
}
}
if (gCCStats.mFile) {
fprintf(gCCStats.mFile, "%s\n", NS_ConvertUTF16toUTF8(msg).get());
}
}
if (sPostGCEventsToObserver) {
const char16_t* kJSONFmt =
u"{ \"timestamp\": %llu, "
u"\"duration\": %lu, "
u"\"max_slice_pause\": %lu, "
u"\"total_slice_pause\": %lu, "
u"\"max_finish_gc_duration\": %lu, "
u"\"max_sync_skippable_duration\": %lu, "
u"\"suspected\": %lu, "
u"\"visited\": { "
u"\"RCed\": %lu, "
u"\"GCed\": %lu }, "
u"\"collected\": { "
u"\"RCed\": %lu, "
u"\"GCed\": %lu }, "
u"\"waiting_for_gc\": %lu, "
u"\"zones_waiting_for_gc\": %lu, "
u"\"short_living_objects_waiting_for_gc\": %lu, "
u"\"forced_gc\": %d, "
u"\"forget_skippable\": { "
u"\"times_before_cc\": %lu, "
u"\"min\": %lu, "
u"\"max\": %lu, "
u"\"avg\": %lu, "
u"\"total\": %lu, "
u"\"removed\": %lu } "
u"}";
nsString json;
nsTextFormatter::ssprintf(json, kJSONFmt, PR_Now(), ccNowDuration,
gCCStats.mMaxSliceTime,
gCCStats.mTotalSliceTime,
gCCStats.mMaxGCDuration,
gCCStats.mMaxSkippableDuration,
gCCStats.mSuspected,
aResults.mVisitedRefCounted, aResults.mVisitedGCed,
aResults.mFreedRefCounted, aResults.mFreedGCed,
sCCollectedWaitingForGC,
sCCollectedZonesWaitingForGC,
sLikelyShortLivingObjectsNeedingGC,
aResults.mForcedGC,
sForgetSkippableBeforeCC,
minForgetSkippableTime / PR_USEC_PER_MSEC,
sMaxForgetSkippableTime / PR_USEC_PER_MSEC,
(sTotalForgetSkippableTime / cleanups) /
PR_USEC_PER_MSEC,
sTotalForgetSkippableTime / PR_USEC_PER_MSEC,
sRemovedPurples);
nsCOMPtr<nsIObserverService> observerService = mozilla::services::GetObserverService();
if (observerService) {
observerService->NotifyObservers(nullptr, "cycle-collection-statistics", json.get());
}
}
// Update global state to indicate we have just run a cycle collection.
sMinForgetSkippableTime = UINT32_MAX;
sMaxForgetSkippableTime = 0;
sTotalForgetSkippableTime = 0;
sRemovedPurples = 0;
sForgetSkippableBeforeCC = 0;
sNeedsFullCC = false;
sNeedsGCAfterCC = false;
gCCStats.Clear();
}
// static
bool
InterSliceGCRunnerFired(TimeStamp aDeadline, void* aData)
{
nsJSContext::KillInterSliceGCRunner();
MOZ_ASSERT(sActiveIntersliceGCBudget > 0);
// We use longer budgets when the CC has been locked out but the CC has tried
// to run since that means we may have significant amount garbage to collect
// and better to GC in several longer slices than in a very long one.
int64_t budget = aDeadline.IsNull() ?
int64_t(sActiveIntersliceGCBudget * 2) :
int64_t((aDeadline - TimeStamp::Now()).ToMilliseconds());
if (sCCLockedOut && sCCLockedOutTime) {
int64_t lockedTime = PR_Now() - sCCLockedOutTime;
int32_t maxSliceGCBudget = sActiveIntersliceGCBudget * 10;
double percentOfLockedTime =
std::min((double)lockedTime / NS_MAX_CC_LOCKEDOUT_TIME, 1.0);
budget =
static_cast<int64_t>(
std::max((double)budget, percentOfLockedTime * maxSliceGCBudget));
}
TimeStamp startTimeStamp = TimeStamp::Now();
TimeDuration duration = sGCUnnotifiedTotalTime;
uintptr_t reason = reinterpret_cast<uintptr_t>(aData);
nsJSContext::GarbageCollectNow(aData ?
static_cast<JS::gcreason::Reason>(reason) :
JS::gcreason::INTER_SLICE_GC,
nsJSContext::IncrementalGC,
nsJSContext::NonShrinkingGC,
budget);
sGCUnnotifiedTotalTime = TimeDuration();
TimeStamp now = TimeStamp::Now();
TimeDuration sliceDuration = now - startTimeStamp;
duration += sliceDuration;
if (duration.ToSeconds()) {
TimeDuration idleDuration;
if (!aDeadline.IsNull()) {
if (aDeadline < now) {
// This slice overflowed the idle period.
idleDuration = aDeadline - startTimeStamp;
} else {
// Note, we don't want to use duration here, since it may contain
// data also from JS engine triggered GC slices.
idleDuration = sliceDuration;
}
}
uint32_t percent =
uint32_t(idleDuration.ToSeconds() / duration.ToSeconds() * 100);
Telemetry::Accumulate(Telemetry::GC_SLICE_DURING_IDLE, percent);
}
return true;
}
// static
void
GCTimerFired(nsITimer *aTimer, void *aClosure)
{
nsJSContext::KillGCTimer();
// Now start the actual GC after initial timer has fired.
sInterSliceGCRunner = IdleTaskRunner::Create([aClosure](TimeStamp aDeadline) {
return InterSliceGCRunnerFired(aDeadline, aClosure);
}, "GCTimerFired::InterSliceGCRunnerFired",
NS_INTERSLICE_GC_DELAY,
sActiveIntersliceGCBudget,
false,
[]{ return sShuttingDown; },
TaskCategory::GarbageCollection);
}
// static
void
ShrinkingGCTimerFired(nsITimer* aTimer, void* aClosure)
{
nsJSContext::KillShrinkingGCTimer();
sIsCompactingOnUserInactive = true;
nsJSContext::GarbageCollectNow(JS::gcreason::USER_INACTIVE,
nsJSContext::IncrementalGC,
nsJSContext::ShrinkingGC);
}
static bool
ShouldTriggerCC(uint32_t aSuspected)
{
return sNeedsFullCC ||
aSuspected > NS_CC_PURPLE_LIMIT ||
(aSuspected > NS_CC_FORCED_PURPLE_LIMIT &&
TimeUntilNow(sLastCCEndTime) > NS_CC_FORCED);
}
static bool
CCRunnerFired(TimeStamp aDeadline)
{
if (sDidShutdown) {
return false;
}
static uint32_t ccDelay = NS_CC_DELAY;
if (sCCLockedOut) {
ccDelay = NS_CC_DELAY / 3;
PRTime now = PR_Now();
if (sCCLockedOutTime == 0) {
// Reset sCCRunnerFireCount so that we run forgetSkippable
// often enough before CC. Because of reduced ccDelay
// forgetSkippable will be called just a few times.
// NS_MAX_CC_LOCKEDOUT_TIME limit guarantees that we end up calling
// forgetSkippable and CycleCollectNow eventually.
sCCRunnerFireCount = 0;
sCCLockedOutTime = now;
return false;
}
if (now - sCCLockedOutTime < NS_MAX_CC_LOCKEDOUT_TIME) {
return false;
}
}
++sCCRunnerFireCount;
bool didDoWork = false;
// During early timer fires, we only run forgetSkippable. During the first
// late timer fire, we decide if we are going to have a second and final
// late timer fire, where we may begin to run the CC. Should run at least one
// early timer fire to allow cleanup before the CC.
int32_t numEarlyTimerFires = std::max((int32_t)ccDelay / NS_CC_SKIPPABLE_DELAY - 2, 1);
bool isLateTimerFire = sCCRunnerFireCount > numEarlyTimerFires;
uint32_t suspected = nsCycleCollector_suspectedCount();
if (isLateTimerFire && ShouldTriggerCC(suspected)) {
if (sCCRunnerFireCount == numEarlyTimerFires + 1) {
FireForgetSkippable(suspected, true, aDeadline);
didDoWork = true;
if (ShouldTriggerCC(nsCycleCollector_suspectedCount())) {
// Our efforts to avoid a CC have failed, so we return to let the
// timer fire once more to trigger a CC.
if (!aDeadline.IsNull() && TimeStamp::Now() < aDeadline) {
// Clear content unbinder before the first CC slice.
Element::ClearContentUnbinder();
if (TimeStamp::Now() < aDeadline) {
// And trigger deferred deletion too.
nsCycleCollector_doDeferredDeletion();
}
}
return didDoWork;
}
} else {
// We are in the final timer fire and still meet the conditions for
// triggering a CC. Let RunCycleCollectorSlice finish the current IGC, if
// any because that will allow us to include the GC time in the CC pause.
nsJSContext::RunCycleCollectorSlice(aDeadline);
didDoWork = true;
}
} else if (((sPreviousSuspectedCount + 100) <= suspected) ||
(sCleanupsSinceLastGC < NS_MAJOR_FORGET_SKIPPABLE_CALLS)) {
// Only do a forget skippable if there are more than a few new objects
// or we're doing the initial forget skippables.
FireForgetSkippable(suspected, false, aDeadline);
didDoWork = true;
}
if (isLateTimerFire) {
ccDelay = NS_CC_DELAY;
// We have either just run the CC or decided we don't want to run the CC
// next time, so kill the timer.
sPreviousSuspectedCount = 0;
nsJSContext::KillCCRunner();
}
return didDoWork;
}
// static
uint32_t
nsJSContext::CleanupsSinceLastGC()
{
return sCleanupsSinceLastGC;
}
// static
void
nsJSContext::LoadStart()
{
sLoadingInProgress = true;
++sPendingLoadCount;
}
// static
void
nsJSContext::LoadEnd()
{
if (!sLoadingInProgress)
return;
// sPendingLoadCount is not a well managed load counter (and doesn't
// need to be), so make sure we don't make it wrap backwards here.
if (sPendingLoadCount > 0) {
--sPendingLoadCount;
return;
}
sLoadingInProgress = false;
}
// Check all of the various collector timers/runners and see if they are waiting to fire.
// This does not check sFullGCTimer, as that's a more expensive collection we run
// on a long timer.
// static
void
nsJSContext::RunNextCollectorTimer(JS::gcreason::Reason aReason,
mozilla::TimeStamp aDeadline)
{
if (sShuttingDown) {
return;
}
if (sGCTimer) {
GCTimerFired(nullptr, reinterpret_cast<void*>(aReason));
return;
}
nsCOMPtr<nsIRunnable> runnable;
if (sInterSliceGCRunner) {
sInterSliceGCRunner->SetDeadline(aDeadline);
runnable = sInterSliceGCRunner;
} else {
// Check the CC timers after the GC timers, because the CC timers won't do
// anything if a GC is in progress.
MOZ_ASSERT(!sCCLockedOut, "Don't check the CC timers if the CC is locked out.");
}
if (sCCRunner) {
sCCRunner->SetDeadline(aDeadline);
runnable = sCCRunner;
}
if (sICCRunner) {
sICCRunner->SetDeadline(aDeadline);
runnable = sICCRunner;
}
if (runnable) {
runnable->Run();
}
}
// static
void
nsJSContext::MaybeRunNextCollectorSlice(nsIDocShell* aDocShell,
JS::gcreason::Reason aReason)
{
if (!aDocShell || !XRE_IsContentProcess()) {
return;
}
nsCOMPtr<nsIDocShellTreeItem> root;
aDocShell->GetSameTypeRootTreeItem(getter_AddRefs(root));
if (root == aDocShell) {
// We don't want to run collectors when loading the top level page.
return;
}
nsIDocument* rootDocument = root->GetDocument();
if (!rootDocument ||
rootDocument->GetReadyStateEnum() != nsIDocument::READYSTATE_COMPLETE ||
rootDocument->IsInBackgroundWindow()) {
return;
}
nsIPresShell* presShell = rootDocument->GetShell();
if (!presShell) {
return;
}
nsViewManager* vm = presShell->GetViewManager();
if (!vm) {
return;
}
// GetLastUserEventTime returns microseconds.
uint32_t lastEventTime = 0;
vm->GetLastUserEventTime(lastEventTime);
uint32_t currentTime =
PR_IntervalToMicroseconds(PR_IntervalNow());
// Only try to trigger collectors more often if user hasn't interacted with
// the page for awhile.
if ((currentTime - lastEventTime) >
(NS_USER_INTERACTION_INTERVAL * PR_USEC_PER_MSEC)) {
Maybe<TimeStamp> next = nsRefreshDriver::GetNextTickHint();
// Try to not delay the next RefreshDriver tick, so give a reasonable
// deadline for collectors.
if (next.isSome()) {
nsJSContext::RunNextCollectorTimer(aReason, next.value());
}
}
}
// static
void
nsJSContext::PokeGC(JS::gcreason::Reason aReason,
JSObject* aObj,
int aDelay)
{
if (sShuttingDown) {
return;
}
if (aObj) {
JS::Zone* zone = JS::GetObjectZone(aObj);
CycleCollectedJSRuntime::Get()->AddZoneWaitingForGC(zone);
} else if (aReason != JS::gcreason::CC_WAITING) {
sNeedsFullGC = true;
}
if (sGCTimer || sInterSliceGCRunner) {
// There's already a timer for GC'ing, just return
return;
}
if (sCCRunner) {
// Make sure CC is called...
sNeedsFullCC = true;
// and GC after it.
sNeedsGCAfterCC = true;
return;
}
if (sICCRunner) {
// Make sure GC is called after the current CC completes.
// No need to set sNeedsFullCC because we are currently running a CC.
sNeedsGCAfterCC = true;
return;
}
CallCreateInstance("@mozilla.org/timer;1", &sGCTimer);
if (!sGCTimer) {
// Failed to create timer (probably because we're in XPCOM shutdown)
return;
}
static bool first = true;
sGCTimer->SetTarget(SystemGroup::EventTargetFor(TaskCategory::GarbageCollection));
sGCTimer->InitWithNamedFuncCallback(GCTimerFired,
reinterpret_cast<void *>(aReason),
aDelay
? aDelay
: (first
? NS_FIRST_GC_DELAY
: NS_GC_DELAY),
nsITimer::TYPE_ONE_SHOT_LOW_PRIORITY,
"GCTimerFired");
first = false;
}
// static
void
nsJSContext::PokeShrinkingGC()
{
if (sShrinkingGCTimer || sShuttingDown) {
return;
}
CallCreateInstance("@mozilla.org/timer;1", &sShrinkingGCTimer);
if (!sShrinkingGCTimer) {
// Failed to create timer (probably because we're in XPCOM shutdown)
return;
}
sShrinkingGCTimer->SetTarget(SystemGroup::EventTargetFor(TaskCategory::GarbageCollection));
sShrinkingGCTimer->InitWithNamedFuncCallback(ShrinkingGCTimerFired, nullptr,
sCompactOnUserInactiveDelay,
nsITimer::TYPE_ONE_SHOT_LOW_PRIORITY,
"ShrinkingGCTimerFired");
}
// static
void
nsJSContext::MaybePokeCC()
{
if (sCCRunner || sICCRunner || sShuttingDown || !sHasRunGC) {
return;
}
uint32_t sinceLastCCEnd = TimeUntilNow(sLastCCEndTime);
if (sinceLastCCEnd && sinceLastCCEnd < NS_CC_DELAY) {
return;
}
if (ShouldTriggerCC(nsCycleCollector_suspectedCount())) {
sCCRunnerFireCount = 0;
// We can kill some objects before running forgetSkippable.
nsCycleCollector_dispatchDeferredDeletion();
sCCRunner =
IdleTaskRunner::Create(CCRunnerFired,
"MaybePokeCC::CCRunnerFired",
NS_CC_SKIPPABLE_DELAY,
kForgetSkippableSliceDuration, true,
[]{ return sShuttingDown; },
TaskCategory::GarbageCollection);
}
}
//static
void
nsJSContext::KillGCTimer()
{
if (sGCTimer) {
sGCTimer->Cancel();
NS_RELEASE(sGCTimer);
}
}
void
nsJSContext::KillFullGCTimer()
{
if (sFullGCTimer) {
sFullGCTimer->Cancel();
NS_RELEASE(sFullGCTimer);
}
}
void
nsJSContext::KillInterSliceGCRunner()
{
if (sInterSliceGCRunner) {
sInterSliceGCRunner->Cancel();
sInterSliceGCRunner = nullptr;
}
}
//static
void
nsJSContext::KillShrinkingGCTimer()
{
if (sShrinkingGCTimer) {
sShrinkingGCTimer->Cancel();
NS_RELEASE(sShrinkingGCTimer);
}
}
//static
void
nsJSContext::KillCCRunner()
{
sCCLockedOutTime = 0;
if (sCCRunner) {
sCCRunner->Cancel();
sCCRunner = nullptr;
}
}
//static
void
nsJSContext::KillICCRunner()
{
sCCLockedOutTime = 0;
if (sICCRunner) {
sICCRunner->Cancel();
sICCRunner = nullptr;
}
}
class NotifyGCEndRunnable : public Runnable
{
nsString mMessage;
public:
explicit NotifyGCEndRunnable(const nsString& aMessage)
: mozilla::Runnable("NotifyGCEndRunnable")
, mMessage(aMessage)
{
}
NS_DECL_NSIRUNNABLE
};
NS_IMETHODIMP
NotifyGCEndRunnable::Run()
{
MOZ_ASSERT(NS_IsMainThread());
nsCOMPtr<nsIObserverService> observerService = mozilla::services::GetObserverService();
if (!observerService) {
return NS_OK;
}
const char16_t oomMsg[3] = { '{', '}', 0 };
const char16_t *toSend = mMessage.get() ? mMessage.get() : oomMsg;
observerService->NotifyObservers(nullptr, "garbage-collection-statistics", toSend);
return NS_OK;
}
static void
DOMGCSliceCallback(JSContext* aCx, JS::GCProgress aProgress, const JS::GCDescription &aDesc)
{
NS_ASSERTION(NS_IsMainThread(), "GCs must run on the main thread");
switch (aProgress) {
case JS::GC_CYCLE_BEGIN: {
// Prevent cycle collections and shrinking during incremental GC.
sCCLockedOut = true;
break;
}
case JS::GC_CYCLE_END: {
PRTime delta = GetCollectionTimeDelta();
if (sPostGCEventsToConsole) {
nsString gcstats;
gcstats.Adopt(aDesc.formatSummaryMessage(aCx));
nsAutoString prefix;
nsTextFormatter::ssprintf(prefix, u"GC(T+%.1f)[%s-%i] ",
double(delta) / PR_USEC_PER_SEC,
ProcessNameForCollectorLog(), getpid());
nsString msg = prefix + gcstats;
nsCOMPtr<nsIConsoleService> cs = do_GetService(NS_CONSOLESERVICE_CONTRACTID);
if (cs) {
cs->LogStringMessage(msg.get());
}
}
if (!sShuttingDown) {
if (sPostGCEventsToObserver || Telemetry::CanRecordExtended()) {
nsString json;
json.Adopt(aDesc.formatJSON(aCx, PR_Now()));
RefPtr<NotifyGCEndRunnable> notify = new NotifyGCEndRunnable(json);
SystemGroup::Dispatch(TaskCategory::GarbageCollection, notify.forget());
}
}
sCCLockedOut = false;
sIsCompactingOnUserInactive = false;
// May need to kill the inter-slice GC runner
nsJSContext::KillInterSliceGCRunner();
sCCollectedWaitingForGC = 0;
sCCollectedZonesWaitingForGC = 0;
sLikelyShortLivingObjectsNeedingGC = 0;
sCleanupsSinceLastGC = 0;
sNeedsFullCC = true;
sHasRunGC = true;
nsJSContext::MaybePokeCC();
if (aDesc.isZone_) {
if (!sFullGCTimer && !sShuttingDown) {
CallCreateInstance("@mozilla.org/timer;1", &sFullGCTimer);
sFullGCTimer->SetTarget(SystemGroup::EventTargetFor(TaskCategory::GarbageCollection));
sFullGCTimer->InitWithNamedFuncCallback(FullGCTimerFired,
nullptr,
NS_FULL_GC_DELAY,
nsITimer::TYPE_ONE_SHOT_LOW_PRIORITY,
"FullGCTimerFired");
}
} else {
nsJSContext::KillFullGCTimer();
}
if (ShouldTriggerCC(nsCycleCollector_suspectedCount())) {
nsCycleCollector_dispatchDeferredDeletion();
}
if (!aDesc.isZone_) {
sNeedsFullGC = false;
}
break;
}
case JS::GC_SLICE_BEGIN:
break;
case JS::GC_SLICE_END:
sGCUnnotifiedTotalTime +=
aDesc.lastSliceEnd(aCx) - aDesc.lastSliceStart(aCx);
// Schedule another GC slice if the GC has more work to do.
nsJSContext::KillInterSliceGCRunner();
if (!sShuttingDown && !aDesc.isComplete_) {
sInterSliceGCRunner =
IdleTaskRunner::Create([](TimeStamp aDeadline) {
return InterSliceGCRunnerFired(aDeadline, nullptr);
}, "DOMGCSliceCallback::InterSliceGCRunnerFired",
NS_INTERSLICE_GC_DELAY,
sActiveIntersliceGCBudget,
false,
[]{ return sShuttingDown; },
TaskCategory::GarbageCollection);
}
if (ShouldTriggerCC(nsCycleCollector_suspectedCount())) {
nsCycleCollector_dispatchDeferredDeletion();
}
if (sPostGCEventsToConsole) {
nsString gcstats;
gcstats.Adopt(aDesc.formatSliceMessage(aCx));
nsAutoString prefix;
nsTextFormatter::ssprintf(prefix, u"[%s-%i] ",
ProcessNameForCollectorLog(), getpid());
nsString msg = prefix + gcstats;
nsCOMPtr<nsIConsoleService> cs = do_GetService(NS_CONSOLESERVICE_CONTRACTID);
if (cs) {
cs->LogStringMessage(msg.get());
}
}
break;
default:
MOZ_CRASH("Unexpected GCProgress value");
}
if (sPrevGCSliceCallback) {
(*sPrevGCSliceCallback)(aCx, aProgress, aDesc);
}
}
void
nsJSContext::SetWindowProxy(JS::Handle<JSObject*> aWindowProxy)
{
mWindowProxy = aWindowProxy;
}
JSObject*
nsJSContext::GetWindowProxy()
{
return mWindowProxy;
}
void
nsJSContext::LikelyShortLivingObjectCreated()
{
++sLikelyShortLivingObjectsNeedingGC;
}
void
mozilla::dom::StartupJSEnvironment()
{
// initialize all our statics, so that we can restart XPCOM
sGCTimer = sShrinkingGCTimer = sFullGCTimer = nullptr;
sCCLockedOut = false;
sCCLockedOutTime = 0;
sLastCCEndTime = TimeStamp();
sHasRunGC = false;
sPendingLoadCount = 0;
sLoadingInProgress = false;
sCCollectedWaitingForGC = 0;
sCCollectedZonesWaitingForGC = 0;
sLikelyShortLivingObjectsNeedingGC = 0;
sPostGCEventsToConsole = false;
sNeedsFullCC = false;
sNeedsFullGC = true;
sNeedsGCAfterCC = false;
gNameSpaceManager = nullptr;
sIsInitialized = false;
sDidShutdown = false;
sShuttingDown = false;
gCCStats.Init();
}
static void
SetGCParameter(JSGCParamKey aParam, uint32_t aValue)
{
AutoJSAPI jsapi;
jsapi.Init();
JS_SetGCParameter(jsapi.cx(), aParam, aValue);
}
static void
ResetGCParameter(JSGCParamKey aParam)
{
AutoJSAPI jsapi;
jsapi.Init();
JS_ResetGCParameter(jsapi.cx(), aParam);
}
static void
SetMemoryPrefChangedCallbackMB(const char* aPrefName, void* aClosure)
{
int32_t prefMB = Preferences::GetInt(aPrefName, -1);
// handle overflow and negative pref values
CheckedInt<int32_t> prefB = CheckedInt<int32_t>(prefMB) * 1024 * 1024;
if (prefB.isValid() && prefB.value() >= 0) {
SetGCParameter((JSGCParamKey)(uintptr_t)aClosure, prefB.value());
} else {
ResetGCParameter((JSGCParamKey)(uintptr_t)aClosure);
}
}
static void
SetMemoryNurseryMaxPrefChangedCallback(const char* aPrefName, void* aClosure)
{
int32_t prefMB = Preferences::GetInt(aPrefName, -1);
// handle overflow and negative pref values
CheckedInt<int32_t> prefB = CheckedInt<int32_t>(prefMB) * 1024;
if (prefB.isValid() && prefB.value() >= 0) {
SetGCParameter((JSGCParamKey)(uintptr_t)aClosure, prefB.value());
} else {
ResetGCParameter((JSGCParamKey)(uintptr_t)aClosure);
}
}
static void
SetMemoryPrefChangedCallbackInt(const char* aPrefName, void* aClosure)
{
int32_t pref = Preferences::GetInt(aPrefName, -1);
// handle overflow and negative pref values
if (pref >= 0 && pref < 10000) {
SetGCParameter((JSGCParamKey)(uintptr_t)aClosure, pref);
} else {
ResetGCParameter((JSGCParamKey)(uintptr_t)aClosure);
}
}
static void
SetMemoryPrefChangedCallbackBool(const char* aPrefName, void* aClosure)
{
bool pref = Preferences::GetBool(aPrefName);
SetGCParameter((JSGCParamKey)(uintptr_t)aClosure, pref);
}
static void
SetMemoryGCModePrefChangedCallback(const char* aPrefName, void* aClosure)
{
bool enableZoneGC = Preferences::GetBool("javascript.options.mem.gc_per_zone");
bool enableIncrementalGC = Preferences::GetBool("javascript.options.mem.gc_incremental");
JSGCMode mode;
if (enableIncrementalGC) {
mode = JSGC_MODE_INCREMENTAL;
} else if (enableZoneGC) {
mode = JSGC_MODE_ZONE;
} else {
mode = JSGC_MODE_GLOBAL;
}
SetGCParameter(JSGC_MODE, mode);
}
static void
SetMemoryGCSliceTimePrefChangedCallback(const char* aPrefName, void* aClosure)
{
int32_t pref = Preferences::GetInt(aPrefName, -1);
// handle overflow and negative pref values
if (pref > 0 && pref < 100000) {
sActiveIntersliceGCBudget = pref;
SetGCParameter(JSGC_SLICE_TIME_BUDGET, pref);
} else {
ResetGCParameter(JSGC_SLICE_TIME_BUDGET);
}
}
static void
SetIncrementalCCPrefChangedCallback(const char* aPrefName, void* aClosure)
{
bool pref = Preferences::GetBool(aPrefName);
sIncrementalCC = pref;
}
static bool
AsmJSCacheOpenEntryForRead(JS::Handle<JSObject*> aGlobal,
const char16_t* aBegin,
const char16_t* aLimit,
size_t* aSize,
const uint8_t** aMemory,
intptr_t *aHandle)
{
nsIPrincipal* principal =
nsJSPrincipals::get(JS_GetCompartmentPrincipals(js::GetObjectCompartment(aGlobal)));
return asmjscache::OpenEntryForRead(principal, aBegin, aLimit, aSize, aMemory,
aHandle);
}
static JS::AsmJSCacheResult
AsmJSCacheOpenEntryForWrite(JS::Handle<JSObject*> aGlobal,
const char16_t* aBegin,
const char16_t* aEnd,
size_t aSize,
uint8_t** aMemory,
intptr_t* aHandle)
{
nsIPrincipal* principal =
nsJSPrincipals::get(JS_GetCompartmentPrincipals(js::GetObjectCompartment(aGlobal)));
return asmjscache::OpenEntryForWrite(principal, aBegin, aEnd, aSize, aMemory,
aHandle);
}
class JSDispatchableRunnable final : public Runnable
{
~JSDispatchableRunnable()
{
MOZ_ASSERT(!mDispatchable);
}
public:
explicit JSDispatchableRunnable(JS::Dispatchable* aDispatchable)
: mozilla::Runnable("JSDispatchableRunnable")
, mDispatchable(aDispatchable)
{
MOZ_ASSERT(mDispatchable);
}
protected:
NS_IMETHOD Run() override
{
MOZ_ASSERT(NS_IsMainThread());
AutoJSAPI jsapi;
jsapi.Init();
JS::Dispatchable::MaybeShuttingDown maybeShuttingDown =
sShuttingDown ? JS::Dispatchable::ShuttingDown : JS::Dispatchable::NotShuttingDown;
mDispatchable->run(jsapi.cx(), maybeShuttingDown);
mDispatchable = nullptr; // mDispatchable may delete itself
return NS_OK;
}
private:
JS::Dispatchable* mDispatchable;
};
static bool
DispatchToEventLoop(void* closure, JS::Dispatchable* aDispatchable)
{
MOZ_ASSERT(!closure);
// This callback may execute either on the main thread or a random JS-internal
// helper thread. This callback can be called during shutdown so we cannot
// simply NS_DispatchToMainThread. Failure during shutdown is expected and
// properly handled by the JS engine.
nsCOMPtr<nsIEventTarget> mainTarget = GetMainThreadEventTarget();
if (!mainTarget) {
return false;
}
RefPtr<JSDispatchableRunnable> r = new JSDispatchableRunnable(aDispatchable);
MOZ_ALWAYS_SUCCEEDS(mainTarget->Dispatch(r.forget(), NS_DISPATCH_NORMAL));
return true;
}
static bool
ConsumeStream(JSContext* aCx,
JS::HandleObject aObj,
JS::MimeType aMimeType,
JS::StreamConsumer* aConsumer)
{
return FetchUtil::StreamResponseToJS(aCx, aObj, aMimeType, aConsumer, nullptr);
}
void
nsJSContext::EnsureStatics()
{
if (sIsInitialized) {
if (!nsContentUtils::XPConnect()) {
MOZ_CRASH();
}
return;
}
// Let's make sure that our main thread is the same as the xpcom main thread.
MOZ_ASSERT(NS_IsMainThread());
AutoJSAPI jsapi;
jsapi.Init();
sPrevGCSliceCallback = JS::SetGCSliceCallback(jsapi.cx(), DOMGCSliceCallback);
// Set up the asm.js cache callbacks
static const JS::AsmJSCacheOps asmJSCacheOps = {
AsmJSCacheOpenEntryForRead,
asmjscache::CloseEntryForRead,
AsmJSCacheOpenEntryForWrite,
asmjscache::CloseEntryForWrite
};
JS::SetAsmJSCacheOps(jsapi.cx(), &asmJSCacheOps);
JS::InitDispatchToEventLoop(jsapi.cx(), DispatchToEventLoop, nullptr);
JS::InitConsumeStreamCallback(jsapi.cx(), ConsumeStream);
// Set these global xpconnect options...
Preferences::RegisterCallbackAndCall(SetMemoryPrefChangedCallbackMB,
"javascript.options.mem.high_water_mark",
(void*)JSGC_MAX_MALLOC_BYTES);
Preferences::RegisterCallbackAndCall(SetMemoryPrefChangedCallbackMB,
"javascript.options.mem.max",
(void*)JSGC_MAX_BYTES);
Preferences::RegisterCallbackAndCall(SetMemoryNurseryMaxPrefChangedCallback,
"javascript.options.mem.nursery.max_kb",
(void*)JSGC_MAX_NURSERY_BYTES);
Preferences::RegisterCallbackAndCall(SetMemoryGCModePrefChangedCallback,
"javascript.options.mem.gc_per_zone");
Preferences::RegisterCallbackAndCall(SetMemoryGCModePrefChangedCallback,
"javascript.options.mem.gc_incremental");
Preferences::RegisterCallbackAndCall(SetMemoryGCSliceTimePrefChangedCallback,
"javascript.options.mem.gc_incremental_slice_ms");
Preferences::RegisterCallbackAndCall(SetMemoryPrefChangedCallbackBool,
"javascript.options.mem.gc_compacting",
(void *)JSGC_COMPACTING_ENABLED);
Preferences::RegisterCallbackAndCall(SetMemoryPrefChangedCallbackInt,
"javascript.options.mem.gc_high_frequency_time_limit_ms",
(void *)JSGC_HIGH_FREQUENCY_TIME_LIMIT);
Preferences::RegisterCallbackAndCall(SetMemoryPrefChangedCallbackBool,
"javascript.options.mem.gc_dynamic_mark_slice",
(void *)JSGC_DYNAMIC_MARK_SLICE);
Preferences::RegisterCallbackAndCall(SetMemoryPrefChangedCallbackBool,
"javascript.options.mem.gc_refresh_frame_slices_enabled",
(void *)JSGC_REFRESH_FRAME_SLICES_ENABLED);
Preferences::RegisterCallbackAndCall(SetMemoryPrefChangedCallbackBool,
"javascript.options.mem.gc_dynamic_heap_growth",
(void *)JSGC_DYNAMIC_HEAP_GROWTH);
Preferences::RegisterCallbackAndCall(SetMemoryPrefChangedCallbackInt,
"javascript.options.mem.gc_low_frequency_heap_growth",
(void *)JSGC_LOW_FREQUENCY_HEAP_GROWTH);
Preferences::RegisterCallbackAndCall(SetMemoryPrefChangedCallbackInt,
"javascript.options.mem.gc_high_frequency_heap_growth_min",
(void *)JSGC_HIGH_FREQUENCY_HEAP_GROWTH_MIN);
Preferences::RegisterCallbackAndCall(SetMemoryPrefChangedCallbackInt,
"javascript.options.mem.gc_high_frequency_heap_growth_max",
(void *)JSGC_HIGH_FREQUENCY_HEAP_GROWTH_MAX);
Preferences::RegisterCallbackAndCall(SetMemoryPrefChangedCallbackInt,
"javascript.options.mem.gc_high_frequency_low_limit_mb",
(void *)JSGC_HIGH_FREQUENCY_LOW_LIMIT);
Preferences::RegisterCallbackAndCall(SetMemoryPrefChangedCallbackInt,
"javascript.options.mem.gc_high_frequency_high_limit_mb",
(void *)JSGC_HIGH_FREQUENCY_HIGH_LIMIT);
Preferences::RegisterCallbackAndCall(SetMemoryPrefChangedCallbackInt,
"javascript.options.mem.gc_allocation_threshold_mb",
(void *)JSGC_ALLOCATION_THRESHOLD);
Preferences::RegisterCallbackAndCall(SetMemoryPrefChangedCallbackInt,
"javascript.options.mem.gc_allocation_threshold_factor",
(void *)JSGC_ALLOCATION_THRESHOLD_FACTOR);
Preferences::RegisterCallbackAndCall(SetMemoryPrefChangedCallbackInt,
"javascript.options.mem.gc_allocation_threshold_factor_avoid_interrupt",
(void *)JSGC_ALLOCATION_THRESHOLD_FACTOR_AVOID_INTERRUPT);
Preferences::RegisterCallbackAndCall(SetIncrementalCCPrefChangedCallback,
"dom.cycle_collector.incremental");
Preferences::RegisterCallbackAndCall(SetMemoryPrefChangedCallbackInt,
"javascript.options.mem.gc_min_empty_chunk_count",
(void *)JSGC_MIN_EMPTY_CHUNK_COUNT);
Preferences::RegisterCallbackAndCall(SetMemoryPrefChangedCallbackInt,
"javascript.options.mem.gc_max_empty_chunk_count",
(void *)JSGC_MAX_EMPTY_CHUNK_COUNT);
nsCOMPtr<nsIObserverService> obs = mozilla::services::GetObserverService();
if (!obs) {
MOZ_CRASH();
}
Preferences::AddBoolVarCache(&sGCOnMemoryPressure,
"javascript.options.gc_on_memory_pressure",
true);
Preferences::AddBoolVarCache(&sCompactOnUserInactive,
"javascript.options.compact_on_user_inactive",
true);
Preferences::AddUintVarCache(&sCompactOnUserInactiveDelay,
"javascript.options.compact_on_user_inactive_delay",
NS_DEAULT_INACTIVE_GC_DELAY);
Preferences::AddBoolVarCache(&sPostGCEventsToConsole,
JS_OPTIONS_DOT_STR "mem.log");
Preferences::AddBoolVarCache(&sPostGCEventsToObserver,
JS_OPTIONS_DOT_STR "mem.notify");
nsIObserver* observer = new nsJSEnvironmentObserver();
obs->AddObserver(observer, "memory-pressure", false);
obs->AddObserver(observer, "user-interaction-inactive", false);
obs->AddObserver(observer, "user-interaction-active", false);
obs->AddObserver(observer, "quit-application", false);
obs->AddObserver(observer, NS_XPCOM_SHUTDOWN_OBSERVER_ID, false);
sIsInitialized = true;
}
nsScriptNameSpaceManager*
mozilla::dom::GetNameSpaceManager()
{
if (sDidShutdown)
return nullptr;
if (!gNameSpaceManager) {
gNameSpaceManager = new nsScriptNameSpaceManager;
NS_ADDREF(gNameSpaceManager);
nsresult rv = gNameSpaceManager->Init();
NS_ENSURE_SUCCESS(rv, nullptr);
}
return gNameSpaceManager;
}
nsScriptNameSpaceManager*
mozilla::dom::PeekNameSpaceManager()
{
return gNameSpaceManager;
}
void
mozilla::dom::ShutdownJSEnvironment()
{
KillTimers();
NS_IF_RELEASE(gNameSpaceManager);
sShuttingDown = true;
sDidShutdown = true;
}
// A fast-array class for JS. This class supports both nsIJSScriptArray and
// nsIArray. If it is JS itself providing and consuming this class, all work
// can be done via nsIJSScriptArray, and avoid the conversion of elements
// to/from nsISupports.
// When consumed by non-JS (eg, another script language), conversion is done
// on-the-fly.
class nsJSArgArray final : public nsIJSArgArray {
public:
nsJSArgArray(JSContext *aContext, uint32_t argc, const JS::Value* argv,
nsresult *prv);
// nsISupports
NS_DECL_CYCLE_COLLECTING_ISUPPORTS
NS_DECL_CYCLE_COLLECTION_SCRIPT_HOLDER_CLASS_AMBIGUOUS(nsJSArgArray,
nsIJSArgArray)
// nsIArray
NS_DECL_NSIARRAY
// nsIJSArgArray
nsresult GetArgs(uint32_t* argc, void** argv) override;
void ReleaseJSObjects();
protected:
~nsJSArgArray();
JSContext *mContext;
JS::Heap<JS::Value> *mArgv;
uint32_t mArgc;
};
nsJSArgArray::nsJSArgArray(JSContext *aContext, uint32_t argc,
const JS::Value* argv, nsresult *prv)
: mContext(aContext)
, mArgv(nullptr)
, mArgc(argc)
{
// copy the array - we don't know its lifetime, and ours is tied to xpcom
// refcounting.
if (argc) {
mArgv = new (fallible) JS::Heap<JS::Value>[argc];
if (!mArgv) {
*prv = NS_ERROR_OUT_OF_MEMORY;
return;
}
}
// Callers are allowed to pass in a null argv even for argc > 0. They can
// then use GetArgs to initialize the values.
if (argv) {
for (uint32_t i = 0; i < argc; ++i)
mArgv[i] = argv[i];
}
if (argc > 0) {
mozilla::HoldJSObjects(this);
}
*prv = NS_OK;
}
nsJSArgArray::~nsJSArgArray()
{
ReleaseJSObjects();
}
void
nsJSArgArray::ReleaseJSObjects()
{
if (mArgv) {
delete [] mArgv;
}
if (mArgc > 0) {
mArgc = 0;
mozilla::DropJSObjects(this);
}
}
// QueryInterface implementation for nsJSArgArray
NS_IMPL_CYCLE_COLLECTION_CLASS(nsJSArgArray)
NS_IMPL_CYCLE_COLLECTION_UNLINK_BEGIN(nsJSArgArray)
tmp->ReleaseJSObjects();
NS_IMPL_CYCLE_COLLECTION_UNLINK_END
NS_IMPL_CYCLE_COLLECTION_TRAVERSE_BEGIN(nsJSArgArray)
NS_IMPL_CYCLE_COLLECTION_TRAVERSE_END
NS_IMPL_CYCLE_COLLECTION_TRACE_BEGIN(nsJSArgArray)
if (tmp->mArgv) {
for (uint32_t i = 0; i < tmp->mArgc; ++i) {
NS_IMPL_CYCLE_COLLECTION_TRACE_JS_MEMBER_CALLBACK(mArgv[i])
}
}
NS_IMPL_CYCLE_COLLECTION_TRACE_END
NS_INTERFACE_MAP_BEGIN_CYCLE_COLLECTION(nsJSArgArray)
NS_INTERFACE_MAP_ENTRY(nsIArray)
NS_INTERFACE_MAP_ENTRY(nsIJSArgArray)
NS_INTERFACE_MAP_ENTRY_AMBIGUOUS(nsISupports, nsIJSArgArray)
NS_INTERFACE_MAP_END
NS_IMPL_CYCLE_COLLECTING_ADDREF(nsJSArgArray)
NS_IMPL_CYCLE_COLLECTING_RELEASE(nsJSArgArray)
nsresult
nsJSArgArray::GetArgs(uint32_t *argc, void **argv)
{
*argv = (void *)mArgv;
*argc = mArgc;
return NS_OK;
}
// nsIArray impl
NS_IMETHODIMP nsJSArgArray::GetLength(uint32_t *aLength)
{
*aLength = mArgc;
return NS_OK;
}
NS_IMETHODIMP nsJSArgArray::QueryElementAt(uint32_t index, const nsIID & uuid, void * *result)
{
*result = nullptr;
if (index >= mArgc)
return NS_ERROR_INVALID_ARG;
if (uuid.Equals(NS_GET_IID(nsIVariant)) || uuid.Equals(NS_GET_IID(nsISupports))) {
// Have to copy a Heap into a Rooted to work with it.
JS::Rooted<JS::Value> val(mContext, mArgv[index]);
return nsContentUtils::XPConnect()->JSToVariant(mContext, val,
(nsIVariant **)result);
}
NS_WARNING("nsJSArgArray only handles nsIVariant");
return NS_ERROR_NO_INTERFACE;
}
NS_IMETHODIMP nsJSArgArray::IndexOf(uint32_t startIndex, nsISupports *element, uint32_t *_retval)
{
return NS_ERROR_NOT_IMPLEMENTED;
}
NS_IMETHODIMP nsJSArgArray::Enumerate(nsISimpleEnumerator **_retval)
{
return NS_ERROR_NOT_IMPLEMENTED;
}
// The factory function
nsresult NS_CreateJSArgv(JSContext *aContext, uint32_t argc,
const JS::Value* argv, nsIJSArgArray **aArray)
{
nsresult rv;
nsCOMPtr<nsIJSArgArray> ret = new nsJSArgArray(aContext, argc, argv, &rv);
if (NS_FAILED(rv)) {
return rv;
}
ret.forget(aArray);
return NS_OK;
}