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diff --git a/dom/messagechannel/MessagePort.h b/dom/messagechannel/MessagePort.h
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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/. */
+
+#ifndef mozilla_dom_MessagePort_h
+#define mozilla_dom_MessagePort_h
+
+#include "mozilla/Attributes.h"
+#include "mozilla/DOMEventTargetHelper.h"
+#include "mozilla/dom/DOMTypes.h"
+#include "mozilla/UniquePtr.h"
+#include "nsTArray.h"
+
+#ifdef XP_WIN
+# undef PostMessage
+#endif
+
+class nsIGlobalObject;
+
+namespace mozilla::dom {
+
+class MessageData;
+class MessagePortChild;
+class PostMessageRunnable;
+class RefMessageBodyService;
+class SharedMessageBody;
+class StrongWorkerRef;
+struct StructuredSerializeOptions;
+
+// A class to hold a MessagePortIdentifier from
+// MessagePort::CloneAndDistentangle() and close if neither passed to
+// MessagePort::Create() nor release()ed to send via IPC.
+// When the `neutered` field of the MessagePortIdentifier is false, a close is
+// required.
+// This does not derive from MessagePortIdentifier because
+// MessagePortIdentifier is final and because use of UniqueMessagePortId as a
+// MessagePortIdentifier is intentionally prevented without release of
+// ownership.
+class UniqueMessagePortId final {
+ public:
+ UniqueMessagePortId() { mIdentifier.neutered() = true; }
+ explicit UniqueMessagePortId(const MessagePortIdentifier& aIdentifier)
+ : mIdentifier(aIdentifier) {}
+ UniqueMessagePortId(UniqueMessagePortId&& aOther) noexcept
+ : mIdentifier(aOther.mIdentifier) {
+ aOther.mIdentifier.neutered() = true;
+ }
+ ~UniqueMessagePortId() { ForceClose(); };
+ void ForceClose();
+
+ [[nodiscard]] MessagePortIdentifier release() {
+ MessagePortIdentifier id = mIdentifier;
+ mIdentifier.neutered() = true;
+ return id;
+ }
+ // const member accessors are not required because a const
+ // UniqueMessagePortId is not useful.
+ nsID& uuid() { return mIdentifier.uuid(); }
+ nsID& destinationUuid() { return mIdentifier.destinationUuid(); }
+ uint32_t& sequenceId() { return mIdentifier.sequenceId(); }
+ bool& neutered() { return mIdentifier.neutered(); }
+
+ UniqueMessagePortId(const UniqueMessagePortId& aOther) = delete;
+ void operator=(const UniqueMessagePortId& aOther) = delete;
+
+ private:
+ MessagePortIdentifier mIdentifier;
+};
+
+class MessagePort final : public DOMEventTargetHelper {
+ friend class PostMessageRunnable;
+
+ public:
+ NS_DECL_ISUPPORTS_INHERITED
+ NS_DECL_CYCLE_COLLECTION_CLASS_INHERITED(MessagePort, DOMEventTargetHelper)
+
+ static already_AddRefed<MessagePort> Create(nsIGlobalObject* aGlobal,
+ const nsID& aUUID,
+ const nsID& aDestinationUUID,
+ ErrorResult& aRv);
+
+ static already_AddRefed<MessagePort> Create(nsIGlobalObject* aGlobal,
+ UniqueMessagePortId& aIdentifier,
+ ErrorResult& aRv);
+
+ // For IPC.
+ static void ForceClose(const MessagePortIdentifier& aIdentifier);
+
+ virtual JSObject* WrapObject(JSContext* aCx,
+ JS::Handle<JSObject*> aGivenProto) override;
+
+ void PostMessage(JSContext* aCx, JS::Handle<JS::Value> aMessage,
+ const Sequence<JSObject*>& aTransferable, ErrorResult& aRv);
+
+ void PostMessage(JSContext* aCx, JS::Handle<JS::Value> aMessage,
+ const StructuredSerializeOptions& aOptions,
+ ErrorResult& aRv);
+
+ void Start();
+
+ void Close();
+
+ EventHandlerNonNull* GetOnmessage();
+
+ void SetOnmessage(EventHandlerNonNull* aCallback);
+
+ IMPL_EVENT_HANDLER(messageerror)
+
+ // Non WebIDL methods
+
+ void UnshippedEntangle(MessagePort* aEntangledPort);
+
+ bool CanBeCloned() const { return !mHasBeenTransferredOrClosed; }
+
+ void CloneAndDisentangle(UniqueMessagePortId& aIdentifier);
+
+ void CloseForced();
+
+ // These methods are useful for MessagePortChild
+
+ void Entangled(nsTArray<MessageData>& aMessages);
+ void MessagesReceived(nsTArray<MessageData>& aMessages);
+ void StopSendingDataConfirmed();
+ void Closed();
+
+ private:
+ enum State {
+ // When a port is created by a MessageChannel it is entangled with the
+ // other. They both run on the same thread, same event loop and the
+ // messages are added to the queues without using PBackground actors.
+ // When one of the port is shipped, the state is changed to
+ // StateEntangling.
+ eStateUnshippedEntangled,
+
+ // If the port is closed or cloned when we are in this state, we go in one
+ // of the following 2 steps. EntanglingForClose or ForDisentangle.
+ eStateEntangling,
+
+ // We are not fully entangled yet but are already disentangled.
+ eStateEntanglingForDisentangle,
+
+ // We are not fully entangled yet but are already closed.
+ eStateEntanglingForClose,
+
+ // When entangled() is received we send all the messages in the
+ // mMessagesForTheOtherPort to the actor and we change the state to
+ // StateEntangled. At this point the port is entangled with the other. We
+ // send and receive messages.
+ // If the port queue is not enabled, the received messages are stored in
+ // the mMessages.
+ eStateEntangled,
+
+ // When the port is cloned or disentangled we want to stop receiving
+ // messages. We call 'SendStopSendingData' to the actor and we wait for an
+ // answer. All the messages received between now and the
+ // 'StopSendingDataComfirmed are queued in the mMessages but not
+ // dispatched.
+ eStateDisentangling,
+
+ // When 'StopSendingDataConfirmed' is received, we can disentangle the port
+ // calling SendDisentangle in the actor because we are 100% sure that we
+ // don't receive any other message, so nothing will be lost.
+ // Disentangling the port we send all the messages from the mMessages
+ // though the actor.
+ eStateDisentangled,
+
+ // We are here if Close() has been called. We are disentangled but we can
+ // still send pending messages.
+ eStateDisentangledForClose
+ };
+
+ explicit MessagePort(nsIGlobalObject* aGlobal, State aState);
+ ~MessagePort();
+
+ void DisconnectFromOwner() override;
+
+ void Initialize(const nsID& aUUID, const nsID& aDestinationUUID,
+ uint32_t aSequenceID, bool aNeutered, ErrorResult& aRv);
+
+ bool ConnectToPBackground();
+
+ // Dispatch events from the Message Queue using a nsRunnable.
+ void Dispatch();
+
+ void DispatchError();
+
+ void StartDisentangling();
+ void Disentangle();
+
+ void RemoveDocFromBFCache();
+
+ void CloseInternal(bool aSoftly);
+
+ // This method is meant to keep alive the MessagePort when this object is
+ // creating the actor and until the actor is entangled.
+ // We release the object when the port is closed or disentangled.
+ void UpdateMustKeepAlive();
+
+ bool IsCertainlyAliveForCC() const override { return mIsKeptAlive; }
+
+ RefPtr<StrongWorkerRef> mWorkerRef;
+
+ RefPtr<PostMessageRunnable> mPostMessageRunnable;
+
+ RefPtr<MessagePortChild> mActor;
+
+ RefPtr<MessagePort> mUnshippedEntangledPort;
+
+ RefPtr<RefMessageBodyService> mRefMessageBodyService;
+
+ nsTArray<RefPtr<SharedMessageBody>> mMessages;
+ nsTArray<RefPtr<SharedMessageBody>> mMessagesForTheOtherPort;
+
+ UniquePtr<MessagePortIdentifier> mIdentifier;
+
+ State mState;
+
+ bool mMessageQueueEnabled;
+
+ bool mIsKeptAlive;
+
+ // mHasBeenTransferredOrClosed is used to know if this port has been manually
+ // closed or transferred via postMessage. Note that if the entangled port is
+ // closed, this port is closed as well (see mState) but, just because close()
+ // has not been called directly, by spec, this port can still be transferred.
+ bool mHasBeenTransferredOrClosed;
+};
+
+} // namespace mozilla::dom
+
+#endif // mozilla_dom_MessagePort_h