gecko-dev/dom/messagechannel/MessagePort.cpp

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/* -*- 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 "MessagePort.h"
#include "MessageEvent.h"
#include "MessagePortChild.h"
#include "mozilla/dom/BlobBinding.h"
#include "mozilla/dom/Event.h"
#include "mozilla/dom/File.h"
#include "mozilla/dom/MessageChannel.h"
#include "mozilla/dom/MessageEventBinding.h"
#include "mozilla/dom/MessagePortBinding.h"
#include "mozilla/dom/MessagePortChild.h"
#include "mozilla/dom/PMessagePort.h"
#include "mozilla/dom/StructuredCloneTags.h"
#include "mozilla/dom/WorkerPrivate.h"
#include "mozilla/dom/WorkerScope.h"
#include "mozilla/ipc/BackgroundChild.h"
#include "mozilla/ipc/PBackgroundChild.h"
#include "mozilla/MessagePortTimelineMarker.h"
#include "mozilla/TimelineConsumers.h"
#include "mozilla/TimelineMarker.h"
#include "mozilla/Unused.h"
#include "nsContentUtils.h"
#include "nsGlobalWindow.h"
#include "nsPresContext.h"
#include "ScriptSettings.h"
#include "SharedMessagePortMessage.h"
#include "nsIBFCacheEntry.h"
#include "nsIDocument.h"
#include "nsIDOMFileList.h"
#include "nsIPresShell.h"
#include "nsISupportsPrimitives.h"
#include "nsServiceManagerUtils.h"
#ifdef XP_WIN
#undef PostMessage
#endif
using namespace mozilla::dom::workers;
namespace mozilla {
namespace dom {
class PostMessageRunnable final : public CancelableRunnable
{
friend class MessagePort;
public:
PostMessageRunnable(MessagePort* aPort, SharedMessagePortMessage* aData)
: mPort(aPort)
, mData(aData)
{
MOZ_ASSERT(aPort);
MOZ_ASSERT(aData);
}
NS_IMETHOD
Run() override
{
NS_ASSERT_OWNINGTHREAD(Runnable);
// The port can be cycle collected while this runnable is pending in
// the event queue.
if (!mPort) {
return NS_OK;
}
MOZ_ASSERT(mPort->mPostMessageRunnable == this);
nsresult rv = DispatchMessage();
// We must check if we were waiting for this message in order to shutdown
// the port.
mPort->UpdateMustKeepAlive();
mPort->mPostMessageRunnable = nullptr;
mPort->Dispatch();
return rv;
}
nsresult
Cancel() override
{
NS_ASSERT_OWNINGTHREAD(Runnable);
mPort = nullptr;
mData = nullptr;
return NS_OK;
}
private:
nsresult
DispatchMessage() const
{
NS_ASSERT_OWNINGTHREAD(Runnable);
nsCOMPtr<nsIGlobalObject> globalObject = mPort->GetParentObject();
AutoJSAPI jsapi;
if (!globalObject || !jsapi.Init(globalObject)) {
NS_WARNING("Failed to initialize AutoJSAPI object.");
return NS_ERROR_FAILURE;
}
JSContext* cx = jsapi.cx();
ErrorResult rv;
JS::Rooted<JS::Value> value(cx);
UniquePtr<AbstractTimelineMarker> start;
UniquePtr<AbstractTimelineMarker> end;
RefPtr<TimelineConsumers> timelines = TimelineConsumers::Get();
bool isTimelineRecording = timelines && !timelines->IsEmpty();
if (isTimelineRecording) {
start = MakeUnique<MessagePortTimelineMarker>(
ProfileTimelineMessagePortOperationType::DeserializeData,
MarkerTracingType::START);
}
mData->Read(cx, &value, rv);
if (isTimelineRecording) {
end = MakeUnique<MessagePortTimelineMarker>(
ProfileTimelineMessagePortOperationType::DeserializeData,
MarkerTracingType::END);
timelines->AddMarkerForAllObservedDocShells(start);
timelines->AddMarkerForAllObservedDocShells(end);
}
if (NS_WARN_IF(rv.Failed())) {
return rv.StealNSResult();
}
// Create the event
nsCOMPtr<mozilla::dom::EventTarget> eventTarget =
do_QueryInterface(mPort->GetOwner());
RefPtr<MessageEvent> event =
new MessageEvent(eventTarget, nullptr, nullptr);
Sequence<OwningNonNull<MessagePort>> ports;
if (!mData->TakeTransferredPortsAsSequence(ports)) {
return NS_ERROR_OUT_OF_MEMORY;
}
event->InitMessageEvent(nullptr, NS_LITERAL_STRING("message"),
false /* non-bubbling */,
false /* cancelable */, value, EmptyString(),
EmptyString(), nullptr, ports);
event->SetTrusted(true);
bool dummy;
mPort->DispatchEvent(static_cast<dom::Event*>(event.get()), &dummy);
return NS_OK;
}
private:
~PostMessageRunnable()
{}
RefPtr<MessagePort> mPort;
RefPtr<SharedMessagePortMessage> mData;
};
NS_IMPL_CYCLE_COLLECTION_CLASS(MessagePort)
NS_IMPL_CYCLE_COLLECTION_UNLINK_BEGIN_INHERITED(MessagePort,
DOMEventTargetHelper)
if (tmp->mPostMessageRunnable) {
NS_IMPL_CYCLE_COLLECTION_UNLINK(mPostMessageRunnable->mPort);
}
NS_IMPL_CYCLE_COLLECTION_UNLINK(mMessages);
NS_IMPL_CYCLE_COLLECTION_UNLINK(mMessagesForTheOtherPort);
NS_IMPL_CYCLE_COLLECTION_UNLINK(mUnshippedEntangledPort);
NS_IMPL_CYCLE_COLLECTION_UNLINK_END
NS_IMPL_CYCLE_COLLECTION_TRAVERSE_BEGIN_INHERITED(MessagePort,
DOMEventTargetHelper)
if (tmp->mPostMessageRunnable) {
NS_IMPL_CYCLE_COLLECTION_TRAVERSE(mPostMessageRunnable->mPort);
}
NS_IMPL_CYCLE_COLLECTION_TRAVERSE(mUnshippedEntangledPort);
NS_IMPL_CYCLE_COLLECTION_TRAVERSE_END
NS_INTERFACE_MAP_BEGIN_CYCLE_COLLECTION_INHERITED(MessagePort)
NS_INTERFACE_MAP_ENTRY(nsIIPCBackgroundChildCreateCallback)
NS_INTERFACE_MAP_ENTRY(nsIObserver)
NS_INTERFACE_MAP_END_INHERITING(DOMEventTargetHelper)
NS_IMPL_ADDREF_INHERITED(MessagePort, DOMEventTargetHelper)
NS_IMPL_RELEASE_INHERITED(MessagePort, DOMEventTargetHelper)
namespace {
class MessagePortWorkerHolder final : public workers::WorkerHolder
{
MessagePort* mPort;
public:
explicit MessagePortWorkerHolder(MessagePort* aPort)
: mPort(aPort)
{
MOZ_ASSERT(aPort);
MOZ_COUNT_CTOR(MessagePortWorkerHolder);
}
virtual bool Notify(workers::Status aStatus) override
{
if (aStatus > Running) {
// We cannot process messages anymore because we cannot dispatch new
// runnables. Let's force a Close().
mPort->CloseForced();
}
return true;
}
private:
~MessagePortWorkerHolder()
{
MOZ_COUNT_DTOR(MessagePortWorkerHolder);
}
};
class ForceCloseHelper final : public nsIIPCBackgroundChildCreateCallback
{
public:
NS_DECL_ISUPPORTS
static void ForceClose(const MessagePortIdentifier& aIdentifier)
{
PBackgroundChild* actor =
mozilla::ipc::BackgroundChild::GetForCurrentThread();
if (actor) {
Unused << actor->SendMessagePortForceClose(aIdentifier.uuid(),
aIdentifier.destinationUuid(),
aIdentifier.sequenceId());
return;
}
RefPtr<ForceCloseHelper> helper = new ForceCloseHelper(aIdentifier);
if (NS_WARN_IF(!mozilla::ipc::BackgroundChild::GetOrCreateForCurrentThread(helper))) {
MOZ_CRASH();
}
}
private:
explicit ForceCloseHelper(const MessagePortIdentifier& aIdentifier)
: mIdentifier(aIdentifier)
{}
~ForceCloseHelper() {}
void ActorFailed() override
{
MOZ_CRASH("Failed to create a PBackgroundChild actor!");
}
void ActorCreated(mozilla::ipc::PBackgroundChild* aActor) override
{
ForceClose(mIdentifier);
}
const MessagePortIdentifier mIdentifier;
};
NS_IMPL_ISUPPORTS(ForceCloseHelper, nsIIPCBackgroundChildCreateCallback)
} // namespace
MessagePort::MessagePort(nsIGlobalObject* aGlobal)
: DOMEventTargetHelper(aGlobal)
, mInnerID(0)
, mMessageQueueEnabled(false)
, mIsKeptAlive(false)
{
MOZ_ASSERT(aGlobal);
mIdentifier = new MessagePortIdentifier();
mIdentifier->neutered() = true;
mIdentifier->sequenceId() = 0;
}
MessagePort::~MessagePort()
{
CloseForced();
MOZ_ASSERT(!mWorkerHolder);
}
/* static */ already_AddRefed<MessagePort>
MessagePort::Create(nsIGlobalObject* aGlobal, const nsID& aUUID,
const nsID& aDestinationUUID, ErrorResult& aRv)
{
MOZ_ASSERT(aGlobal);
RefPtr<MessagePort> mp = new MessagePort(aGlobal);
mp->Initialize(aUUID, aDestinationUUID, 1 /* 0 is an invalid sequence ID */,
false /* Neutered */, eStateUnshippedEntangled, aRv);
return mp.forget();
}
/* static */ already_AddRefed<MessagePort>
MessagePort::Create(nsIGlobalObject* aGlobal,
const MessagePortIdentifier& aIdentifier,
ErrorResult& aRv)
{
MOZ_ASSERT(aGlobal);
RefPtr<MessagePort> mp = new MessagePort(aGlobal);
mp->Initialize(aIdentifier.uuid(), aIdentifier.destinationUuid(),
aIdentifier.sequenceId(), aIdentifier.neutered(),
eStateEntangling, aRv);
return mp.forget();
}
void
MessagePort::UnshippedEntangle(MessagePort* aEntangledPort)
{
MOZ_ASSERT(aEntangledPort);
MOZ_ASSERT(!mUnshippedEntangledPort);
mUnshippedEntangledPort = aEntangledPort;
}
void
MessagePort::Initialize(const nsID& aUUID,
const nsID& aDestinationUUID,
uint32_t aSequenceID, bool mNeutered,
State aState, ErrorResult& aRv)
{
MOZ_ASSERT(mIdentifier);
mIdentifier->uuid() = aUUID;
mIdentifier->destinationUuid() = aDestinationUUID;
mIdentifier->sequenceId() = aSequenceID;
mState = aState;
if (mNeutered) {
// If this port is neutered we don't want to keep it alive artificially nor
// we want to add listeners or workerWorkerHolders.
mState = eStateDisentangled;
return;
}
if (mState == eStateEntangling) {
ConnectToPBackground();
} else {
MOZ_ASSERT(mState == eStateUnshippedEntangled);
}
// The port has to keep itself alive until it's entangled.
UpdateMustKeepAlive();
if (!NS_IsMainThread()) {
WorkerPrivate* workerPrivate = GetCurrentThreadWorkerPrivate();
MOZ_ASSERT(workerPrivate);
MOZ_ASSERT(!mWorkerHolder);
nsAutoPtr<WorkerHolder> workerHolder(new MessagePortWorkerHolder(this));
if (NS_WARN_IF(!workerHolder->HoldWorker(workerPrivate, Closing))) {
aRv.Throw(NS_ERROR_FAILURE);
return;
}
mWorkerHolder = Move(workerHolder);
} else if (GetOwner()) {
MOZ_ASSERT(NS_IsMainThread());
MOZ_ASSERT(GetOwner()->IsInnerWindow());
mInnerID = GetOwner()->WindowID();
nsCOMPtr<nsIObserverService> obs = mozilla::services::GetObserverService();
if (obs) {
obs->AddObserver(this, "inner-window-destroyed", false);
}
}
}
JSObject*
MessagePort::WrapObject(JSContext* aCx, JS::Handle<JSObject*> aGivenProto)
{
return MessagePortBinding::Wrap(aCx, this, aGivenProto);
}
void
MessagePort::PostMessage(JSContext* aCx, JS::Handle<JS::Value> aMessage,
const Sequence<JSObject*>& aTransferable,
ErrorResult& aRv)
{
// We *must* clone the data here, or the JS::Value could be modified
// by script
// Here we want to check if the transerable object list contains
// this port.
for (uint32_t i = 0; i < aTransferable.Length(); ++i) {
JSObject* object = aTransferable[i];
if (!object) {
continue;
}
MessagePort* port = nullptr;
nsresult rv = UNWRAP_OBJECT(MessagePort, object, port);
if (NS_SUCCEEDED(rv) && port == this) {
aRv.Throw(NS_ERROR_DOM_DATA_CLONE_ERR);
return;
}
}
JS::Rooted<JS::Value> transferable(aCx, JS::UndefinedValue());
aRv = nsContentUtils::CreateJSValueFromSequenceOfObject(aCx, aTransferable,
&transferable);
if (NS_WARN_IF(aRv.Failed())) {
return;
}
RefPtr<SharedMessagePortMessage> data = new SharedMessagePortMessage();
UniquePtr<AbstractTimelineMarker> start;
UniquePtr<AbstractTimelineMarker> end;
RefPtr<TimelineConsumers> timelines = TimelineConsumers::Get();
bool isTimelineRecording = timelines && !timelines->IsEmpty();
if (isTimelineRecording) {
start = MakeUnique<MessagePortTimelineMarker>(
ProfileTimelineMessagePortOperationType::SerializeData,
MarkerTracingType::START);
}
data->Write(aCx, aMessage, transferable, aRv);
if (isTimelineRecording) {
end = MakeUnique<MessagePortTimelineMarker>(
ProfileTimelineMessagePortOperationType::SerializeData,
MarkerTracingType::END);
timelines->AddMarkerForAllObservedDocShells(start);
timelines->AddMarkerForAllObservedDocShells(end);
}
if (NS_WARN_IF(aRv.Failed())) {
return;
}
// This message has to be ignored.
if (mState > eStateEntangled) {
return;
}
// If we are unshipped we are connected to the other port on the same thread.
if (mState == eStateUnshippedEntangled) {
MOZ_ASSERT(mUnshippedEntangledPort);
mUnshippedEntangledPort->mMessages.AppendElement(data);
mUnshippedEntangledPort->Dispatch();
return;
}
// Not entangled yet, but already closed/disentangled.
if (mState == eStateEntanglingForDisentangle ||
mState == eStateEntanglingForClose) {
return;
}
RemoveDocFromBFCache();
// Not entangled yet.
if (mState == eStateEntangling) {
mMessagesForTheOtherPort.AppendElement(data);
return;
}
MOZ_ASSERT(mActor);
MOZ_ASSERT(mMessagesForTheOtherPort.IsEmpty());
AutoTArray<RefPtr<SharedMessagePortMessage>, 1> array;
array.AppendElement(data);
AutoTArray<ClonedMessageData, 1> messages;
// note: `messages` will borrow the underlying buffer, but this is okay
// because reverse destruction order means `messages` will be destroyed prior
// to `array`/`data`.
SharedMessagePortMessage::FromSharedToMessagesChild(mActor, array, messages);
mActor->SendPostMessages(messages);
}
void
MessagePort::Start()
{
if (mMessageQueueEnabled) {
return;
}
mMessageQueueEnabled = true;
Dispatch();
}
void
MessagePort::Dispatch()
{
if (!mMessageQueueEnabled || mMessages.IsEmpty() || mPostMessageRunnable) {
return;
}
switch (mState) {
case eStateUnshippedEntangled:
// Everything is fine here. We have messages because the other
// port populates our queue directly.
break;
case eStateEntangling:
// Everything is fine here as well. We have messages because the other
// port populated our queue directly when we were in the
// eStateUnshippedEntangled state.
break;
case eStateEntanglingForDisentangle:
// Here we don't want to ship messages because these messages must be
// delivered by the cloned version of this one. They will be sent in the
// SendDisentangle().
return;
case eStateEntanglingForClose:
// We still want to deliver messages if we are closing. These messages
// are here from the previous eStateUnshippedEntangled state.
break;
case eStateEntangled:
// This port is up and running.
break;
case eStateDisentangling:
// If we are in the process to disentangle the port, we cannot dispatch
// messages. They will be sent to the cloned version of this port via
// SendDisentangle();
return;
case eStateDisentangled:
MOZ_CRASH("This cannot happen.");
// It cannot happen because Disentangle should take off all the pending
// messages.
break;
case eStateDisentangledForClose:
// If we are here is because the port has been closed. We can still
// process the pending messages.
break;
}
RefPtr<SharedMessagePortMessage> data = mMessages.ElementAt(0);
mMessages.RemoveElementAt(0);
mPostMessageRunnable = new PostMessageRunnable(this, data);
nsCOMPtr<nsIGlobalObject> global = GetOwnerGlobal();
if (NS_IsMainThread() && global) {
MOZ_ALWAYS_SUCCEEDS(global->Dispatch("MessagePortMessage", TaskCategory::Other, do_AddRef(mPostMessageRunnable)));
return;
}
MOZ_ALWAYS_SUCCEEDS(NS_DispatchToCurrentThread(mPostMessageRunnable));
}
void
MessagePort::Close()
{
CloseInternal(true /* aSoftly */);
}
void
MessagePort::CloseForced()
{
CloseInternal(false /* aSoftly */);
}
void
MessagePort::CloseInternal(bool aSoftly)
{
// If we have some messages to send but we don't want a 'soft' close, we have
// to flush them now.
if (!aSoftly) {
mMessages.Clear();
}
if (mState == eStateUnshippedEntangled) {
MOZ_ASSERT(mUnshippedEntangledPort);
// This avoids loops.
RefPtr<MessagePort> port = Move(mUnshippedEntangledPort);
MOZ_ASSERT(mUnshippedEntangledPort == nullptr);
mState = eStateDisentangledForClose;
port->CloseInternal(aSoftly);
UpdateMustKeepAlive();
return;
}
// Not entangled yet, we have to wait.
if (mState == eStateEntangling) {
mState = eStateEntanglingForClose;
return;
}
// Not entangled but already cloned or closed
if (mState == eStateEntanglingForDisentangle ||
mState == eStateEntanglingForClose) {
return;
}
// Maybe we were already closing the port but softly. In this case we call
// UpdateMustKeepAlive() to consider the empty pending message queue.
if (mState == eStateDisentangledForClose && !aSoftly) {
UpdateMustKeepAlive();
return;
}
if (mState > eStateEntangled) {
return;
}
// We don't care about stopping the sending of messages because from now all
// the incoming messages will be ignored.
mState = eStateDisentangledForClose;
MOZ_ASSERT(mActor);
mActor->SendClose();
mActor->SetPort(nullptr);
mActor = nullptr;
UpdateMustKeepAlive();
}
EventHandlerNonNull*
MessagePort::GetOnmessage()
{
if (NS_IsMainThread()) {
return GetEventHandler(nsGkAtoms::onmessage, EmptyString());
}
return GetEventHandler(nullptr, NS_LITERAL_STRING("message"));
}
void
MessagePort::SetOnmessage(EventHandlerNonNull* aCallback)
{
if (NS_IsMainThread()) {
SetEventHandler(nsGkAtoms::onmessage, EmptyString(), aCallback);
} else {
SetEventHandler(nullptr, NS_LITERAL_STRING("message"), aCallback);
}
// When using onmessage, the call to start() is implied.
Start();
}
// This method is called when the PMessagePortChild actor is entangled to
// another actor. It receives a list of messages to be dispatch. It can be that
// we were waiting for this entangling step in order to disentangle the port or
// to close it.
void
MessagePort::Entangled(nsTArray<ClonedMessageData>& aMessages)
{
MOZ_ASSERT(mState == eStateEntangling ||
mState == eStateEntanglingForDisentangle ||
mState == eStateEntanglingForClose);
State oldState = mState;
mState = eStateEntangled;
// If we have pending messages, these have to be sent.
if (!mMessagesForTheOtherPort.IsEmpty()) {
{
nsTArray<ClonedMessageData> messages;
SharedMessagePortMessage::FromSharedToMessagesChild(mActor,
mMessagesForTheOtherPort,
messages);
mActor->SendPostMessages(messages);
}
// Because `messages` borrow the underlying JSStructuredCloneData buffers,
// only clear after `messages` have gone out of scope.
mMessagesForTheOtherPort.Clear();
}
// We must convert the messages into SharedMessagePortMessages to avoid leaks.
FallibleTArray<RefPtr<SharedMessagePortMessage>> data;
if (NS_WARN_IF(!SharedMessagePortMessage::FromMessagesToSharedChild(aMessages,
data))) {
// OOM, we cannot continue.
return;
}
// If the next step is to close the port, we do it ignoring the received
// messages.
if (oldState == eStateEntanglingForClose) {
CloseForced();
return;
}
mMessages.AppendElements(data);
// We were waiting for the entangling callback in order to disentangle this
// port immediately after.
if (oldState == eStateEntanglingForDisentangle) {
StartDisentangling();
return;
}
Dispatch();
}
void
MessagePort::StartDisentangling()
{
MOZ_ASSERT(mActor);
MOZ_ASSERT(mState == eStateEntangled);
mState = eStateDisentangling;
// Sending this message we communicate to the parent actor that we don't want
// to receive any new messages. It is possible that a message has been
// already sent but not received yet. So we have to collect all of them and
// we send them in the SendDispatch() request.
mActor->SendStopSendingData();
}
void
MessagePort::MessagesReceived(nsTArray<ClonedMessageData>& aMessages)
{
MOZ_ASSERT(mState == eStateEntangled ||
mState == eStateDisentangling ||
// This last step can happen only if Close() has been called
// manually. At this point SendClose() is sent but we can still
// receive something until the Closing request is processed.
mState == eStateDisentangledForClose);
MOZ_ASSERT(mMessagesForTheOtherPort.IsEmpty());
RemoveDocFromBFCache();
FallibleTArray<RefPtr<SharedMessagePortMessage>> data;
if (NS_WARN_IF(!SharedMessagePortMessage::FromMessagesToSharedChild(aMessages,
data))) {
// OOM, We cannot continue.
return;
}
mMessages.AppendElements(data);
if (mState == eStateEntangled) {
Dispatch();
}
}
void
MessagePort::StopSendingDataConfirmed()
{
MOZ_ASSERT(mState == eStateDisentangling);
MOZ_ASSERT(mActor);
Disentangle();
}
void
MessagePort::Disentangle()
{
MOZ_ASSERT(mState == eStateDisentangling);
MOZ_ASSERT(mActor);
mState = eStateDisentangled;
{
nsTArray<ClonedMessageData> messages;
SharedMessagePortMessage::FromSharedToMessagesChild(mActor, mMessages,
messages);
mActor->SendDisentangle(messages);
}
// Only clear mMessages after the ClonedMessageData instances have gone out of
// scope because they borrow mMessages' underlying JSStructuredCloneDatas.
mMessages.Clear();
mActor->SetPort(nullptr);
mActor = nullptr;
UpdateMustKeepAlive();
}
void
MessagePort::CloneAndDisentangle(MessagePortIdentifier& aIdentifier)
{
MOZ_ASSERT(mIdentifier);
// We can clone a port that has already been transfered. In this case, on the
// otherside will have a neutered port. Here we set neutered to true so that
// we are safe in case a early return.
aIdentifier.neutered() = true;
if (mState > eStateEntangled) {
return;
}
// We already have a 'next step'. We have to consider this port as already
// cloned/closed/disentangled.
if (mState == eStateEntanglingForDisentangle ||
mState == eStateEntanglingForClose) {
return;
}
aIdentifier.uuid() = mIdentifier->uuid();
aIdentifier.destinationUuid() = mIdentifier->destinationUuid();
aIdentifier.sequenceId() = mIdentifier->sequenceId() + 1;
aIdentifier.neutered() = false;
// We have to entangle first.
if (mState == eStateUnshippedEntangled) {
MOZ_ASSERT(mUnshippedEntangledPort);
MOZ_ASSERT(mMessagesForTheOtherPort.IsEmpty());
// Disconnect the entangled port and connect it to PBackground.
mUnshippedEntangledPort->ConnectToPBackground();
mUnshippedEntangledPort = nullptr;
// In this case, we don't need to be connected to the PBackground service.
if (mMessages.IsEmpty()) {
aIdentifier.sequenceId() = mIdentifier->sequenceId();
mState = eStateDisentangled;
UpdateMustKeepAlive();
return;
}
// Register this component to PBackground.
ConnectToPBackground();
mState = eStateEntanglingForDisentangle;
return;
}
// Not entangled yet, we have to wait.
if (mState == eStateEntangling) {
mState = eStateEntanglingForDisentangle;
return;
}
MOZ_ASSERT(mState == eStateEntangled);
StartDisentangling();
}
void
MessagePort::Closed()
{
if (mState >= eStateDisentangled) {
return;
}
mState = eStateDisentangledForClose;
if (mActor) {
mActor->SetPort(nullptr);
mActor = nullptr;
}
UpdateMustKeepAlive();
}
void
MessagePort::ConnectToPBackground()
{
mState = eStateEntangling;
PBackgroundChild* actor =
mozilla::ipc::BackgroundChild::GetForCurrentThread();
if (actor) {
ActorCreated(actor);
} else {
if (NS_WARN_IF(
!mozilla::ipc::BackgroundChild::GetOrCreateForCurrentThread(this))) {
MOZ_CRASH();
}
}
}
void
MessagePort::ActorFailed()
{
MOZ_CRASH("Failed to create a PBackgroundChild actor!");
}
void
MessagePort::ActorCreated(mozilla::ipc::PBackgroundChild* aActor)
{
MOZ_ASSERT(aActor);
MOZ_ASSERT(!mActor);
MOZ_ASSERT(mIdentifier);
MOZ_ASSERT(mState == eStateEntangling ||
mState == eStateEntanglingForDisentangle ||
mState == eStateEntanglingForClose);
PMessagePortChild* actor =
aActor->SendPMessagePortConstructor(mIdentifier->uuid(),
mIdentifier->destinationUuid(),
mIdentifier->sequenceId());
mActor = static_cast<MessagePortChild*>(actor);
MOZ_ASSERT(mActor);
mActor->SetPort(this);
}
void
MessagePort::UpdateMustKeepAlive()
{
if (mState >= eStateDisentangled &&
mMessages.IsEmpty() &&
mIsKeptAlive) {
mIsKeptAlive = false;
// The DTOR of this WorkerHolder will release the worker for us.
mWorkerHolder = nullptr;
if (NS_IsMainThread()) {
nsCOMPtr<nsIObserverService> obs =
do_GetService("@mozilla.org/observer-service;1");
if (obs) {
obs->RemoveObserver(this, "inner-window-destroyed");
}
}
Release();
return;
}
if (mState < eStateDisentangled && !mIsKeptAlive) {
mIsKeptAlive = true;
AddRef();
}
}
NS_IMETHODIMP
MessagePort::Observe(nsISupports* aSubject, const char* aTopic,
const char16_t* aData)
{
MOZ_ASSERT(NS_IsMainThread());
if (strcmp(aTopic, "inner-window-destroyed")) {
return NS_OK;
}
// If the window id destroyed we have to release the reference that we are
// keeping.
if (!mIsKeptAlive) {
return NS_OK;
}
nsCOMPtr<nsISupportsPRUint64> wrapper = do_QueryInterface(aSubject);
NS_ENSURE_TRUE(wrapper, NS_ERROR_FAILURE);
uint64_t innerID;
nsresult rv = wrapper->GetData(&innerID);
NS_ENSURE_SUCCESS(rv, rv);
if (innerID == mInnerID) {
CloseForced();
}
return NS_OK;
}
void
MessagePort::RemoveDocFromBFCache()
{
if (!NS_IsMainThread()) {
return;
}
nsPIDOMWindowInner* window = GetOwner();
if (!window) {
return;
}
nsIDocument* doc = window->GetExtantDoc();
if (!doc) {
return;
}
nsCOMPtr<nsIBFCacheEntry> bfCacheEntry = doc->GetBFCacheEntry();
if (!bfCacheEntry) {
return;
}
bfCacheEntry->RemoveFromBFCacheSync();
}
/* static */ void
MessagePort::ForceClose(const MessagePortIdentifier& aIdentifier)
{
ForceCloseHelper::ForceClose(aIdentifier);
}
} // namespace dom
} // namespace mozilla