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 COMPUTER, 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 COMPUTER, 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#ifndef MessagePort_h
28#define MessagePort_h
29
30#include "EventListener.h"
31#include "EventTarget.h"
32#include "MessagePortChannel.h"
33#include <wtf/Forward.h>
34#include <wtf/OwnPtr.h>
35#include <wtf/PassOwnPtr.h>
36#include <wtf/PassRefPtr.h>
37#include <wtf/RefPtr.h>
38#include <wtf/Vector.h>
39#include <wtf/text/AtomicStringHash.h>
40
41namespace WebCore {
42
43    class Event;
44    class Frame;
45    class MessagePort;
46    class ScriptExecutionContext;
47
48    // The overwhelmingly common case is sending a single port, so handle that efficiently with an inline buffer of size 1.
49    typedef Vector<RefPtr<MessagePort>, 1> MessagePortArray;
50
51    class MessagePort : public RefCounted<MessagePort>, public EventTarget {
52    public:
53        static PassRefPtr<MessagePort> create(ScriptExecutionContext& scriptExecutionContext) { return adoptRef(new MessagePort(scriptExecutionContext)); }
54        ~MessagePort();
55
56        void postMessage(PassRefPtr<SerializedScriptValue> message, ExceptionCode&);
57        void postMessage(PassRefPtr<SerializedScriptValue> message, const MessagePortArray*, ExceptionCode&);
58        // FIXME: remove this when we update the ObjC bindings (bug #28774).
59        void postMessage(PassRefPtr<SerializedScriptValue> message, MessagePort*, ExceptionCode&);
60
61        void start();
62        void close();
63
64        void entangle(PassOwnPtr<MessagePortChannel>);
65        PassOwnPtr<MessagePortChannel> disentangle(ExceptionCode&);
66
67        // Disentangle an array of ports, returning the entangled channels.
68        // Per section 8.3.3 of the HTML5 spec, generates an INVALID_STATE_ERR exception if any of the passed ports are null or not entangled.
69        // Returns 0 if there is an exception, or if the passed-in array is 0/empty.
70        static PassOwnPtr<MessagePortChannelArray> disentanglePorts(const MessagePortArray*, ExceptionCode&);
71
72        // Entangles an array of channels, returning an array of MessagePorts in matching order.
73        // Returns 0 if the passed array is 0/empty.
74        static PassOwnPtr<MessagePortArray> entanglePorts(ScriptExecutionContext&, PassOwnPtr<MessagePortChannelArray>);
75
76        void messageAvailable();
77        bool started() const { return m_started; }
78
79        void contextDestroyed();
80
81        virtual ScriptExecutionContext* scriptExecutionContext() const;
82
83        virtual MessagePort* toMessagePort() { return this; }
84
85        void dispatchMessages();
86
87        using RefCounted<MessagePort>::ref;
88        using RefCounted<MessagePort>::deref;
89
90        bool hasPendingActivity();
91
92        void setOnmessage(PassRefPtr<EventListener> listener)
93        {
94            setAttributeEventListener(eventNames().messageEvent, listener);
95            start();
96        }
97        EventListener* onmessage() { return getAttributeEventListener(eventNames().messageEvent); }
98
99        // Returns null if there is no entangled port, or if the entangled port is run by a different thread.
100        // Returns null otherwise.
101        // NOTE: This is used solely to enable a GC optimization. Some platforms may not be able to determine ownership of the remote port (since it may live cross-process) - those platforms may always return null.
102        MessagePort* locallyEntangledPort();
103        // A port starts out its life entangled, and remains entangled until it is closed or is cloned.
104        bool isEntangled() { return !m_closed && !isCloned(); }
105        // A port is cloned if its entangled channel has been removed and sent to a new owner via postMessage().
106        bool isCloned() { return !m_entangledChannel; }
107
108    private:
109        MessagePort(ScriptExecutionContext&);
110
111        virtual void refEventTarget() { ref(); }
112        virtual void derefEventTarget() { deref(); }
113        virtual EventTargetData* eventTargetData();
114        virtual EventTargetData* ensureEventTargetData();
115
116        OwnPtr<MessagePortChannel> m_entangledChannel;
117
118        bool m_started;
119        bool m_closed;
120
121        ScriptExecutionContext* m_scriptExecutionContext;
122        EventTargetData m_eventTargetData;
123    };
124
125} // namespace WebCore
126
127#endif // MessagePort_h
128