WebCore/plugins/win/PluginMessageThrottlerWin.cpp
changeset 0 4f2f89ce4247
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/WebCore/plugins/win/PluginMessageThrottlerWin.cpp	Fri Sep 17 09:02:29 2010 +0300
@@ -0,0 +1,151 @@
+/*
+ * Copyright (C) 2006, 2007, 2008 Apple Inc. All Rights Reserved.
+ * Copyright (C) 2008 Collabora, Ltd. All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. 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.
+ *
+ * THIS SOFTWARE IS PROVIDED BY APPLE INC. ``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 APPLE INC. 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 "PluginMessageThrottlerWin.h"
+
+#include "PluginView.h"
+#include <wtf/ASCIICType.h>
+#include <wtf/CurrentTime.h>
+
+using namespace WTF;
+
+namespace WebCore {
+
+// Set a timer to make sure we process any queued messages at least every 16ms.
+// This value allows Flash 60 messages/second, which should be enough for video
+// playback, and also gets us over the limit for kicking into high-resolution
+// timer mode (see SharedTimerWin.cpp).
+static const double MessageThrottleTimeInterval = 0.016;
+
+// During a continuous stream of messages, process one every 5ms.
+static const double MessageDirectProcessingInterval = 0.005;
+
+PluginMessageThrottlerWin::PluginMessageThrottlerWin(PluginView* pluginView)
+    : m_pluginView(pluginView)
+    , m_back(0)
+    , m_front(0)
+    , m_lastMessageTime(0)
+    , m_messageThrottleTimer(this, &PluginMessageThrottlerWin::messageThrottleTimerFired)
+{
+    // Initialize the free list with our inline messages
+    for (unsigned i = 0; i < NumInlineMessages - 1; i++)
+        m_inlineMessages[i].next = &m_inlineMessages[i + 1];
+    m_inlineMessages[NumInlineMessages - 1].next = 0;
+    m_freeInlineMessages = &m_inlineMessages[0];
+}
+
+PluginMessageThrottlerWin::~PluginMessageThrottlerWin()
+{
+    PluginMessage* next;
+
+    for (PluginMessage* message = m_front; message; message = next) {
+        next = message->next;
+        freeMessage(message);
+    }
+}
+
+void PluginMessageThrottlerWin::appendMessage(HWND hWnd, UINT msg, WPARAM wParam, LPARAM lParam)
+{
+    PluginMessage* message = allocateMessage();
+
+    message->hWnd = hWnd;
+    message->msg = msg;
+    message->wParam = wParam;
+    message->lParam = lParam;
+    message->next = 0;
+
+    if (m_back)
+        m_back->next = message;
+    m_back = message;
+    if (!m_front)
+        m_front = message;
+
+    // If it has been more than MessageDirectProcessingInterval between throttled messages,
+    // go ahead and process a message directly.
+    double currentTime = WTF::currentTime();
+    if (currentTime - m_lastMessageTime > MessageDirectProcessingInterval) {
+        processQueuedMessage();
+        m_lastMessageTime = currentTime;
+        if (!m_front)
+            return;
+    }
+
+    if (!m_messageThrottleTimer.isActive())
+        m_messageThrottleTimer.startOneShot(MessageThrottleTimeInterval);
+}
+
+void PluginMessageThrottlerWin::processQueuedMessage()
+{
+    PluginMessage* message = m_front;
+    m_front = m_front->next;
+    if (message == m_back)
+        m_back = 0;
+
+    // Protect the PluginView from destruction while calling its window proc.
+    // <rdar://problem/6930280>
+    RefPtr<PluginView> protect(m_pluginView);
+    ::CallWindowProc(m_pluginView->pluginWndProc(), message->hWnd, message->msg, message->wParam, message->lParam);
+
+    freeMessage(message);
+}
+
+void PluginMessageThrottlerWin::messageThrottleTimerFired(Timer<PluginMessageThrottlerWin>*)
+{
+    processQueuedMessage();
+
+    if (m_front)
+        m_messageThrottleTimer.startOneShot(MessageThrottleTimeInterval);
+}
+
+PluginMessage* PluginMessageThrottlerWin::allocateMessage()
+{
+    PluginMessage *message;
+
+    if (m_freeInlineMessages) {
+        message = m_freeInlineMessages;
+        m_freeInlineMessages = message->next;
+    } else
+        message = new PluginMessage;
+
+    return message;
+}
+
+bool PluginMessageThrottlerWin::isInlineMessage(PluginMessage* message)
+{
+    return message >= &m_inlineMessages[0] && message <= &m_inlineMessages[NumInlineMessages - 1];
+}
+
+void PluginMessageThrottlerWin::freeMessage(PluginMessage* message)
+{
+    if (isInlineMessage(message)) {
+        message->next = m_freeInlineMessages;
+        m_freeInlineMessages = message;
+    } else
+        delete message;
+}
+
+} // namespace WebCore