Home | History | Annotate | Download | only in dom 
      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 
     41 namespace 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