summaryrefslogtreecommitdiffstats
path: root/Source/WebCore/platform/win/SharedTimerWin.cpp
blob: b7367aa1193cd0e8d4561b82550838b63d8d4b75 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
/*
 * Copyright (C) 2006 Apple Computer, 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:
 * 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 COMPUTER, 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 COMPUTER, 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 "SharedTimer.h"

#include "Page.h"
#include "Settings.h"
#include "WebCoreInstanceHandle.h"
#include "Widget.h"
#include <wtf/Assertions.h>
#include <wtf/CurrentTime.h>

// Note: wx headers set defines that affect the configuration of windows.h
// so we must include the wx header first to get unicode versions of functions,
// etc.
#if PLATFORM(WX)
#include <wx/wx.h>
#endif

#include <windows.h>
#include <mmsystem.h>

#if PLATFORM(WIN)
#include "PluginView.h"
#endif

// These aren't in winuser.h with the MSVS 2003 Platform SDK, 
// so use default values in that case.
#ifndef USER_TIMER_MINIMUM
#define USER_TIMER_MINIMUM 0x0000000A
#endif

#ifndef USER_TIMER_MAXIMUM
#define USER_TIMER_MAXIMUM 0x7FFFFFFF
#endif

#ifndef QS_RAWINPUT
#define QS_RAWINPUT         0x0400
#endif

namespace WebCore {

static UINT timerID;
static void (*sharedTimerFiredFunction)();

static HWND timerWindowHandle = 0;
static UINT timerFiredMessage = 0;
static HANDLE timerQueue;
static HANDLE timer;
static bool highResTimerActive;
static bool processingCustomTimerMessage = false;
static LONG pendingTimers;

const LPCWSTR kTimerWindowClassName = L"TimerWindowClass";
const int timerResolution = 1; // To improve timer resolution, we call timeBeginPeriod/timeEndPeriod with this value to increase timer resolution to 1ms.
const int highResolutionThresholdMsec = 16; // Only activate high-res timer for sub-16ms timers (Windows can fire timers at 16ms intervals without changing the system resolution).
const int stopHighResTimerInMsec = 300; // Stop high-res timer after 0.3 seconds to lessen power consumption (we don't use a smaller time since oscillating between high and low resolution breaks timer accuracy on XP).

enum {
    sharedTimerID = 1000,
    endHighResTimerID = 1001,
};

LRESULT CALLBACK TimerWindowWndProc(HWND hWnd, UINT message, WPARAM wParam, LPARAM lParam)
{
#if PLATFORM(WIN)
    // Windows Media Player has a modal message loop that will deliver messages
    // to us at inappropriate times and we will crash if we handle them when
    // they are delivered. We repost all messages so that we will get to handle
    // them once the modal loop exits.
    if (PluginView::isCallingPlugin()) {
        PostMessage(hWnd, message, wParam, lParam);
        return 0;
    }
#endif

    if (message == timerFiredMessage) {
        InterlockedExchange(&pendingTimers, 0);
        processingCustomTimerMessage = true;
        sharedTimerFiredFunction();
        processingCustomTimerMessage = false;
    } else if (message == WM_TIMER) {
        if (wParam == sharedTimerID) {
            KillTimer(timerWindowHandle, sharedTimerID);
            sharedTimerFiredFunction();
        } else if (wParam == endHighResTimerID) {
            KillTimer(timerWindowHandle, endHighResTimerID);
            highResTimerActive = false;
            timeEndPeriod(timerResolution);
        }
    } else
        return DefWindowProc(hWnd, message, wParam, lParam);

    return 0;
}

static void initializeOffScreenTimerWindow()
{
    if (timerWindowHandle)
        return;
    
    WNDCLASSEX wcex;
    memset(&wcex, 0, sizeof(WNDCLASSEX));
    wcex.cbSize = sizeof(WNDCLASSEX);
    wcex.lpfnWndProc    = TimerWindowWndProc;
    wcex.hInstance      = WebCore::instanceHandle();
    wcex.lpszClassName  = kTimerWindowClassName;
    RegisterClassEx(&wcex);

    timerWindowHandle = CreateWindow(kTimerWindowClassName, 0, 0,
       CW_USEDEFAULT, 0, CW_USEDEFAULT, 0, HWND_MESSAGE, 0, WebCore::instanceHandle(), 0);
    timerFiredMessage = RegisterWindowMessage(L"com.apple.WebKit.TimerFired");
}

void setSharedTimerFiredFunction(void (*f)())
{
    sharedTimerFiredFunction = f;
}

static void NTAPI queueTimerProc(PVOID, BOOLEAN)
{
    if (InterlockedIncrement(&pendingTimers) == 1)
        PostMessage(timerWindowHandle, timerFiredMessage, 0, 0);
}

void setSharedTimerFireTime(double fireTime)
{
    ASSERT(sharedTimerFiredFunction);

    double interval = fireTime - currentTime();
    unsigned intervalInMS;
    if (interval < 0)
        intervalInMS = 0;
    else {
        interval *= 1000;
        if (interval > USER_TIMER_MAXIMUM)
            intervalInMS = USER_TIMER_MAXIMUM;
        else
            intervalInMS = (unsigned)interval;
    }

    initializeOffScreenTimerWindow();
    bool timerSet = false;

    if (Settings::shouldUseHighResolutionTimers()) {
        if (interval < highResolutionThresholdMsec) {
            if (!highResTimerActive) {
                highResTimerActive = true;
                timeBeginPeriod(timerResolution);
            }
            SetTimer(timerWindowHandle, endHighResTimerID, stopHighResTimerInMsec, 0);
        }

        DWORD queueStatus = LOWORD(GetQueueStatus(QS_PAINT | QS_MOUSEBUTTON | QS_KEY | QS_RAWINPUT));

        // Win32 has a tri-level queue with application messages > user input > WM_PAINT/WM_TIMER.

        // If the queue doesn't contains input events, we use a higher priorty timer event posting mechanism.
        if (!(queueStatus & (QS_MOUSEBUTTON | QS_KEY | QS_RAWINPUT))) {
            if (intervalInMS < USER_TIMER_MINIMUM && !processingCustomTimerMessage && !(queueStatus & QS_PAINT)) {
                // Call PostMessage immediately if the timer is already expired, unless a paint is pending.
                // (we prioritize paints over timers)
                if (InterlockedIncrement(&pendingTimers) == 1)
                    PostMessage(timerWindowHandle, timerFiredMessage, 0, 0);
                timerSet = true;
            } else {
                // Otherwise, delay the PostMessage via a CreateTimerQueueTimer
                if (!timerQueue)
                    timerQueue = CreateTimerQueue();
                if (timer)
                    DeleteTimerQueueTimer(timerQueue, timer, 0);
                timerSet = CreateTimerQueueTimer(&timer, timerQueue, queueTimerProc, 0, intervalInMS, 0, WT_EXECUTEINTIMERTHREAD | WT_EXECUTEONLYONCE);
            }
        }
    }

    if (timerSet) {
        if (timerID) {
            KillTimer(timerWindowHandle, timerID);
            timerID = 0;
        }
    } else {
        timerID = SetTimer(timerWindowHandle, sharedTimerID, intervalInMS, 0);
        timer = 0;
    }
}

void stopSharedTimer()
{
    if (timerQueue && timer) {
        DeleteTimerQueueTimer(timerQueue, timer, 0);
        timer = 0;
    }

    if (timerID) {
        KillTimer(timerWindowHandle, timerID);
        timerID = 0;
    }
}

}