1/*
2 * Copyright (C) 2006, 2007, 2008 Apple Inc. All Rights Reserved.
3 * Copyright (C) 2008 Collabora, Ltd. All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
8 * 1. Redistributions of source code must retain the above copyright
9 *    notice, this list of conditions and the following disclaimer.
10 * 2. Redistributions in binary form must reproduce the above copyright
11 *    notice, this list of conditions and the following disclaimer in the
12 *    documentation and/or other materials provided with the distribution.
13 *
14 * THIS SOFTWARE IS PROVIDED BY APPLE INC. ``AS IS'' AND ANY
15 * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
16 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
17 * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL APPLE INC. OR
18 * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
19 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
20 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
21 * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY
22 * OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
23 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
24 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
25 */
26
27#include "config.h"
28#include "PluginMessageThrottlerWin.h"
29
30#include "PluginView.h"
31#include <wtf/ASCIICType.h>
32#include <wtf/CurrentTime.h>
33
34using namespace WTF;
35
36namespace WebCore {
37
38// Set a timer to make sure we process any queued messages at least every 16ms.
39// This value allows Flash 60 messages/second, which should be enough for video
40// playback, and also gets us over the limit for kicking into high-resolution
41// timer mode (see SharedTimerWin.cpp).
42static const double MessageThrottleTimeInterval = 0.016;
43
44// During a continuous stream of messages, process one every 5ms.
45static const double MessageDirectProcessingInterval = 0.005;
46
47PluginMessageThrottlerWin::PluginMessageThrottlerWin(PluginView* pluginView)
48    : m_pluginView(pluginView)
49    , m_back(0)
50    , m_front(0)
51    , m_messageThrottleTimer(this, &PluginMessageThrottlerWin::messageThrottleTimerFired)
52    , m_lastMessageTime(0)
53{
54    // Initialize the free list with our inline messages
55    for (unsigned i = 0; i < NumInlineMessages - 1; i++)
56        m_inlineMessages[i].next = &m_inlineMessages[i + 1];
57    m_inlineMessages[NumInlineMessages - 1].next = 0;
58    m_freeInlineMessages = &m_inlineMessages[0];
59}
60
61PluginMessageThrottlerWin::~PluginMessageThrottlerWin()
62{
63    PluginMessage* next;
64
65    for (PluginMessage* message = m_front; message; message = next) {
66        next = message->next;
67        freeMessage(message);
68    }
69}
70
71void PluginMessageThrottlerWin::appendMessage(HWND hWnd, UINT msg, WPARAM wParam, LPARAM lParam)
72{
73    PluginMessage* message = allocateMessage();
74
75    message->hWnd = hWnd;
76    message->msg = msg;
77    message->wParam = wParam;
78    message->lParam = lParam;
79    message->next = 0;
80
81    if (m_back)
82        m_back->next = message;
83    m_back = message;
84    if (!m_front)
85        m_front = message;
86
87    // If it has been more than MessageDirectProcessingInterval between throttled messages,
88    // go ahead and process a message directly.
89    double currentTime = WTF::currentTime();
90    if (currentTime - m_lastMessageTime > MessageDirectProcessingInterval) {
91        processQueuedMessage();
92        m_lastMessageTime = currentTime;
93        if (!m_front)
94            return;
95    }
96
97    if (!m_messageThrottleTimer.isActive())
98        m_messageThrottleTimer.startOneShot(MessageThrottleTimeInterval);
99}
100
101void PluginMessageThrottlerWin::processQueuedMessage()
102{
103    PluginMessage* message = m_front;
104    m_front = m_front->next;
105    if (message == m_back)
106        m_back = 0;
107
108    // Protect the PluginView from destruction while calling its window proc.
109    // <rdar://problem/6930280>
110    RefPtr<PluginView> protect(m_pluginView);
111    ::CallWindowProc(m_pluginView->pluginWndProc(), message->hWnd, message->msg, message->wParam, message->lParam);
112
113    freeMessage(message);
114}
115
116void PluginMessageThrottlerWin::messageThrottleTimerFired(Timer<PluginMessageThrottlerWin>*)
117{
118    processQueuedMessage();
119
120    if (m_front)
121        m_messageThrottleTimer.startOneShot(MessageThrottleTimeInterval);
122}
123
124PluginMessage* PluginMessageThrottlerWin::allocateMessage()
125{
126    PluginMessage *message;
127
128    if (m_freeInlineMessages) {
129        message = m_freeInlineMessages;
130        m_freeInlineMessages = message->next;
131    } else
132        message = new PluginMessage;
133
134    return message;
135}
136
137bool PluginMessageThrottlerWin::isInlineMessage(PluginMessage* message)
138{
139    return message >= &m_inlineMessages[0] && message <= &m_inlineMessages[NumInlineMessages - 1];
140}
141
142void PluginMessageThrottlerWin::freeMessage(PluginMessage* message)
143{
144    if (isInlineMessage(message)) {
145        message->next = m_freeInlineMessages;
146        m_freeInlineMessages = message;
147    } else
148        delete message;
149}
150
151} // namespace WebCore
152