1/*
2 * Copyright (C) 2008 Apple Inc. All Rights Reserved.
3 *
4 * Redistribution and use in source and binary forms, with or without
5 * modification, are permitted provided that the following conditions
6 * are met:
7 * 1. Redistributions of source code must retain the above copyright
8 * notice, this list of conditions and the following disclaimer.
9 * 2. Redistributions in binary form must reproduce the above copyright
10 * notice, this list of conditions and the following disclaimer in the
11 * documentation and/or other materials provided with the distribution.
12 *
13 * THIS SOFTWARE IS PROVIDED BY APPLE INC. ``AS IS'' AND ANY
14 * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
15 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
16 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL APPLE INC. OR
17 * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
18 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
19 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
20 * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY
21 * OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
22 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
23 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
24 *
25 */
26
27#pragma once
28
29#include "ActiveDOMObject.h"
30#include "EventTarget.h"
31#include "ExceptionOr.h"
32#include "MessagePortChannel.h"
33#include "MessagePortIdentifier.h"
34#include "MessageWithMessagePorts.h"
35#include <wtf/WeakPtr.h>
36
37namespace JSC {
38class ExecState;
39class JSObject;
40class JSValue;
41}
42
43namespace WebCore {
44
45class Frame;
46
47class MessagePort final : public ActiveDOMObject, public EventTargetWithInlineData, public CanMakeWeakPtr<MessagePort> {
48 WTF_MAKE_NONCOPYABLE(MessagePort);
49 WTF_MAKE_ISO_ALLOCATED(MessagePort);
50public:
51 static Ref<MessagePort> create(ScriptExecutionContext&, const MessagePortIdentifier& local, const MessagePortIdentifier& remote);
52 virtual ~MessagePort();
53
54 ExceptionOr<void> postMessage(JSC::ExecState&, JSC::JSValue message, Vector<JSC::Strong<JSC::JSObject>>&&);
55
56 void start();
57 void close();
58 void entangle();
59
60 // Returns nullptr if the passed-in vector is empty.
61 static ExceptionOr<TransferredMessagePortArray> disentanglePorts(Vector<RefPtr<MessagePort>>&&);
62 static Vector<RefPtr<MessagePort>> entanglePorts(ScriptExecutionContext&, TransferredMessagePortArray&&);
63
64 WEBCORE_EXPORT static bool isExistingMessagePortLocallyReachable(const MessagePortIdentifier&);
65 WEBCORE_EXPORT static void notifyMessageAvailable(const MessagePortIdentifier&);
66
67 WEBCORE_EXPORT void messageAvailable();
68 bool started() const { return m_started; }
69 bool closed() const { return m_closed; }
70
71 void dispatchMessages();
72
73 // Returns null if there is no entangled port, or if the entangled port is run by a different thread.
74 // This is used solely to enable a GC optimization. Some platforms may not be able to determine ownership
75 // of the remote port (since it may live cross-process) - those platforms may always return null.
76 MessagePort* locallyEntangledPort() const;
77
78 const MessagePortIdentifier& identifier() const { return m_identifier; }
79 const MessagePortIdentifier& remoteIdentifier() const { return m_remoteIdentifier; }
80
81 WEBCORE_EXPORT void ref() const;
82 WEBCORE_EXPORT void deref() const;
83
84 // ActiveDOMObject
85 const char* activeDOMObjectName() const final;
86 bool canSuspendForDocumentSuspension() const final;
87 void contextDestroyed() final;
88 void stop() final { close(); }
89 bool hasPendingActivity() const final;
90
91 WEBCORE_EXPORT bool isLocallyReachable() const;
92
93 // EventTargetWithInlineData.
94 EventTargetInterface eventTargetInterface() const final { return MessagePortEventTargetInterfaceType; }
95 ScriptExecutionContext* scriptExecutionContext() const final { return ActiveDOMObject::scriptExecutionContext(); }
96 void refEventTarget() final { ref(); }
97 void derefEventTarget() final { deref(); }
98
99private:
100 explicit MessagePort(ScriptExecutionContext&, const MessagePortIdentifier& local, const MessagePortIdentifier& remote);
101
102 bool addEventListener(const AtomicString& eventType, Ref<EventListener>&&, const AddEventListenerOptions&) final;
103 bool removeEventListener(const AtomicString& eventType, EventListener&, const ListenerOptions&) final;
104
105 void disentangle();
106
107 void registerLocalActivity();
108
109 // A port starts out its life entangled, and remains entangled until it is closed or is cloned.
110 bool isEntangled() const { return !m_closed && m_entangled; }
111
112 void updateActivity(MessagePortChannelProvider::HasActivity);
113
114 bool m_started { false };
115 bool m_closed { false };
116 bool m_entangled { true };
117
118 // Flags to manage querying the remote port for GC purposes
119 mutable bool m_mightBeEligibleForGC { false };
120 mutable bool m_hasHadLocalActivitySinceLastCheck { false };
121 mutable bool m_isRemoteEligibleForGC { false };
122 mutable bool m_isAskingRemoteAboutGC { false };
123 bool m_hasMessageEventListener { false };
124
125 MessagePortIdentifier m_identifier;
126 MessagePortIdentifier m_remoteIdentifier;
127
128 mutable std::atomic<unsigned> m_refCount { 1 };
129};
130
131} // namespace WebCore
132