Imported WebKit commit 2ea9d364d0f6efa8fa64acf19f451504c59be0e4 (http://svn.webkit.org/repository/webkit/trunk@104285)

2 files changed, 360 insertions, 0 deletions

diff --git a/Source/WebCore/dom/default/PlatformMessagePortChannel.cpp b/Source/WebCore/dom/default/PlatformMessagePortChannel.cpp
new file mode 100644
index 000000000..20ffec43b
--- /dev/null
+++ b/Source/WebCore/dom/default/PlatformMessagePortChannel.cpp
@@ -0,0 +1,244 @@
+/*
+ * Copyright (C) 2009 Google Inc. All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are
+ * met:
+ *
+ *     * Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ *     * Redistributions in binary form must reproduce the above
+ * copyright notice, this list of conditions and the following disclaimer
+ * in the documentation and/or other materials provided with the
+ * distribution.
+ *     * Neither the name of Google Inc. nor the names of its
+ * contributors may be used to endorse or promote products derived from
+ * this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+ * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#include "config.h"
+#include "PlatformMessagePortChannel.h"
+
+#include "MessagePort.h"
+#include "ScriptExecutionContext.h"
+
+namespace WebCore {
+
+// MessagePortChannel implementations - just delegate to the PlatformMessagePortChannel.
+void MessagePortChannel::createChannel(PassRefPtr<MessagePort> port1, PassRefPtr<MessagePort> port2)
+{
+    PlatformMessagePortChannel::createChannel(port1, port2);
+}
+
+PassOwnPtr<MessagePortChannel> MessagePortChannel::create(PassRefPtr<PlatformMessagePortChannel> channel)
+{
+    return adoptPtr(new MessagePortChannel(channel));
+}
+
+MessagePortChannel::MessagePortChannel(PassRefPtr<PlatformMessagePortChannel> channel)
+    : m_channel(channel)
+{
+}
+
+MessagePortChannel::~MessagePortChannel()
+{
+    // Make sure we close our platform channel when the base is freed, to keep the channel objects from leaking.
+    m_channel->close();
+}
+
+bool MessagePortChannel::entangleIfOpen(MessagePort* port)
+{
+    return m_channel->entangleIfOpen(port);
+}
+
+void MessagePortChannel::disentangle()
+{
+    m_channel->disentangle();
+}
+
+void MessagePortChannel::postMessageToRemote(PassOwnPtr<MessagePortChannel::EventData> message)
+{
+    m_channel->postMessageToRemote(message);
+}
+
+bool MessagePortChannel::tryGetMessageFromRemote(OwnPtr<MessagePortChannel::EventData>& result)
+{
+    return m_channel->tryGetMessageFromRemote(result);
+}
+
+void MessagePortChannel::close()
+{
+    m_channel->close();
+}
+
+bool MessagePortChannel::isConnectedTo(MessagePort* port)
+{
+    return m_channel->isConnectedTo(port);
+}
+
+bool MessagePortChannel::hasPendingActivity()
+{
+    return m_channel->hasPendingActivity();
+}
+
+MessagePort* MessagePortChannel::locallyEntangledPort(const ScriptExecutionContext* context)
+{
+    return m_channel->locallyEntangledPort(context);
+}
+
+PassRefPtr<PlatformMessagePortChannel> PlatformMessagePortChannel::create(PassRefPtr<MessagePortQueue> incoming, PassRefPtr<MessagePortQueue> outgoing)
+{
+    return adoptRef(new PlatformMessagePortChannel(incoming, outgoing));
+}
+
+PlatformMessagePortChannel::PlatformMessagePortChannel(PassRefPtr<MessagePortQueue> incoming, PassRefPtr<MessagePortQueue> outgoing)
+    : m_entangledChannel(0)
+    , m_incomingQueue(incoming)
+    , m_outgoingQueue(outgoing)
+    , m_remotePort(0)
+{
+}
+
+PlatformMessagePortChannel::~PlatformMessagePortChannel()
+{
+}
+
+void PlatformMessagePortChannel::createChannel(PassRefPtr<MessagePort> port1, PassRefPtr<MessagePort> port2)
+{
+    // Create incoming/outgoing queues.
+    RefPtr<PlatformMessagePortChannel::MessagePortQueue> queue1 = PlatformMessagePortChannel::MessagePortQueue::create();
+    RefPtr<PlatformMessagePortChannel::MessagePortQueue> queue2 = PlatformMessagePortChannel::MessagePortQueue::create();
+
+    // Create proxies for each endpoint.
+    RefPtr<PlatformMessagePortChannel> channel1 = PlatformMessagePortChannel::create(queue1, queue2);
+    RefPtr<PlatformMessagePortChannel> channel2 = PlatformMessagePortChannel::create(queue2, queue1);
+
+    // Entangle the two endpoints.
+    channel1->setEntangledChannel(channel2);
+    channel2->setEntangledChannel(channel1);
+
+    // Now entangle the proxies with the appropriate local ports.
+    port1->entangle(MessagePortChannel::create(channel2));
+    port2->entangle(MessagePortChannel::create(channel1));
+}
+
+bool PlatformMessagePortChannel::entangleIfOpen(MessagePort* port)
+{
+    // We can't call member functions on our remote pair while holding our mutex or we'll deadlock, but we need to guard against the remote port getting closed/freed, so create a standalone reference.
+    RefPtr<PlatformMessagePortChannel> remote = entangledChannel();
+    if (!remote)
+        return false;
+    remote->setRemotePort(port);
+    return true;
+}
+
+void PlatformMessagePortChannel::disentangle()
+{
+    RefPtr<PlatformMessagePortChannel> remote = entangledChannel();
+    if (remote)
+        remote->setRemotePort(0);
+}
+
+void PlatformMessagePortChannel::setRemotePort(MessagePort* port)
+{
+    MutexLocker lock(m_mutex);
+    // Should never set port if it is already set.
+    ASSERT(!port || !m_remotePort);
+    m_remotePort = port;
+}
+
+MessagePort* PlatformMessagePortChannel::remotePort()
+{
+    MutexLocker lock(m_mutex);
+    return m_remotePort;
+}
+
+PassRefPtr<PlatformMessagePortChannel> PlatformMessagePortChannel::entangledChannel()
+{
+    MutexLocker lock(m_mutex);
+    return m_entangledChannel;
+}
+
+void PlatformMessagePortChannel::setEntangledChannel(PassRefPtr<PlatformMessagePortChannel> remote)
+{
+    MutexLocker lock(m_mutex);
+    // Should only be set as part of initial creation/entanglement.
+    if (remote)
+        ASSERT(!m_entangledChannel.get());
+    m_entangledChannel = remote;
+}
+
+void PlatformMessagePortChannel::postMessageToRemote(PassOwnPtr<MessagePortChannel::EventData> message)
+{
+    MutexLocker lock(m_mutex);
+    if (!m_outgoingQueue)
+        return;
+    bool wasEmpty = m_outgoingQueue->appendAndCheckEmpty(message);
+    if (wasEmpty && m_remotePort)
+        m_remotePort->messageAvailable();
+}
+
+bool PlatformMessagePortChannel::tryGetMessageFromRemote(OwnPtr<MessagePortChannel::EventData>& result)
+{
+    MutexLocker lock(m_mutex);
+    result = m_incomingQueue->tryGetMessage();
+    return result;
+}
+
+bool PlatformMessagePortChannel::isConnectedTo(MessagePort* port)
+{
+    MutexLocker lock(m_mutex);
+    return m_remotePort == port;
+}
+
+// Closes the port so no further messages can be sent from either end.
+void PlatformMessagePortChannel::close()
+{
+    RefPtr<PlatformMessagePortChannel> remote = entangledChannel();
+    if (!remote)
+        return;
+    closeInternal();
+    remote->closeInternal();
+}
+
+void PlatformMessagePortChannel::closeInternal()
+{
+    MutexLocker lock(m_mutex);
+    // Disentangle ourselves from the other end. We still maintain a reference to our incoming queue, since previously-existing messages should still be delivered.
+    m_remotePort = 0;
+    m_entangledChannel = 0;
+    m_outgoingQueue = 0;
+}
+
+bool PlatformMessagePortChannel::hasPendingActivity()
+{
+    MutexLocker lock(m_mutex);
+    return !m_incomingQueue->isEmpty();
+}
+
+MessagePort* PlatformMessagePortChannel::locallyEntangledPort(const ScriptExecutionContext* context)
+{
+    MutexLocker lock(m_mutex);
+    // See if both contexts are run by the same thread (are the same context, or are both documents).
+    if (m_remotePort) {
+        // The remote port's ScriptExecutionContext is guaranteed not to change here - MessagePort::contextDestroyed() will close the port before the context goes away, and close() will block because we are holding the mutex.
+        ScriptExecutionContext* remoteContext = m_remotePort->scriptExecutionContext();
+        if (remoteContext == context || (remoteContext && remoteContext->isDocument() && context->isDocument()))
+            return m_remotePort;
+    }
+    return 0;
+}
+
+} // namespace WebCore
diff --git a/Source/WebCore/dom/default/PlatformMessagePortChannel.h b/Source/WebCore/dom/default/PlatformMessagePortChannel.h
new file mode 100644
index 000000000..651810b19
--- /dev/null
+++ b/Source/WebCore/dom/default/PlatformMessagePortChannel.h
@@ -0,0 +1,116 @@
+/*
+ * Copyright (C) 2009 Google Inc. All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are
+ * met:
+ *
+ *     * Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ *     * Redistributions in binary form must reproduce the above
+ * copyright notice, this list of conditions and the following disclaimer
+ * in the documentation and/or other materials provided with the
+ * distribution.
+ *     * Neither the name of Google Inc. nor the names of its
+ * contributors may be used to endorse or promote products derived from
+ * this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+ * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#ifndef PlatformMessagePortChannel_h
+#define PlatformMessagePortChannel_h
+
+#include "MessagePortChannel.h"
+
+#include <wtf/MessageQueue.h>
+#include <wtf/PassRefPtr.h>
+#include <wtf/Threading.h>
+
+namespace WebCore {
+
+    class MessagePort;
+
+    // PlatformMessagePortChannel is a platform-dependent interface to the remote side of a message channel.
+    // This default implementation supports multiple threads running within a single process. Implementations for multi-process platforms should define these public APIs in their own platform-specific PlatformMessagePortChannel file.
+    // The goal of this implementation is to eliminate contention except when cloning or closing the port, so each side of the channel has its own separate mutex.
+    class PlatformMessagePortChannel : public ThreadSafeRefCounted<PlatformMessagePortChannel> {
+    public:
+        static void createChannel(PassRefPtr<MessagePort>, PassRefPtr<MessagePort>);
+
+        // APIs delegated from MessagePortChannel.h
+        bool entangleIfOpen(MessagePort*);
+        void disentangle();
+        void postMessageToRemote(PassOwnPtr<MessagePortChannel::EventData>);
+        bool tryGetMessageFromRemote(OwnPtr<MessagePortChannel::EventData>&);
+        void close();
+        bool isConnectedTo(MessagePort*);
+        bool hasPendingActivity();
+        MessagePort* locallyEntangledPort(const ScriptExecutionContext*);
+
+        // Wrapper for MessageQueue that allows us to do thread safe sharing by two proxies.
+        class MessagePortQueue : public ThreadSafeRefCounted<MessagePortQueue> {
+        public:
+            static PassRefPtr<MessagePortQueue> create() { return adoptRef(new MessagePortQueue()); }
+
+            PassOwnPtr<MessagePortChannel::EventData> tryGetMessage()
+            {
+                return m_queue.tryGetMessage();
+            }
+
+            bool appendAndCheckEmpty(PassOwnPtr<MessagePortChannel::EventData> message)
+            {
+                return m_queue.appendAndCheckEmpty(message);
+            }
+
+            bool isEmpty()
+            {
+                return m_queue.isEmpty();
+            }
+
+        private:
+            MessagePortQueue() { }
+
+            MessageQueue<MessagePortChannel::EventData> m_queue;
+        };
+
+        ~PlatformMessagePortChannel();
+
+    private:
+        static PassRefPtr<PlatformMessagePortChannel> create(PassRefPtr<MessagePortQueue> incoming, PassRefPtr<MessagePortQueue> outgoing);
+        PlatformMessagePortChannel(PassRefPtr<MessagePortQueue> incoming, PassRefPtr<MessagePortQueue> outgoing);
+
+        PassRefPtr<PlatformMessagePortChannel> entangledChannel();
+        void setEntangledChannel(PassRefPtr<PlatformMessagePortChannel>);
+
+        void setRemotePort(MessagePort*);
+        MessagePort* remotePort();
+        void closeInternal();
+
+        // Mutex used to ensure exclusive access to the object internals.
+        Mutex m_mutex;
+
+        // Pointer to our entangled pair - cleared when close() is called.
+        RefPtr<PlatformMessagePortChannel> m_entangledChannel;
+
+        // Reference to the message queue for the (local) entangled port.
+        RefPtr<MessagePortQueue> m_incomingQueue;
+        RefPtr<MessagePortQueue> m_outgoingQueue;
+
+        // The port we are connected to (the remote port) - this is the port that is notified when new messages arrive.
+        MessagePort* m_remotePort;
+    };
+
+} // namespace WebCore
+
+#endif // PlatformMessagePortChannel_h