1/*
2 * Copyright (C) 2014 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 INC. AND ITS CONTRIBUTORS ``AS IS''
14 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,
15 * THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
16 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL APPLE INC. OR ITS CONTRIBUTORS
17 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
18 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
19 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
20 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
21 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
22 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF
23 * THE POSSIBILITY OF SUCH DAMAGE.
24 */
25
26#ifndef ProcessThrottler_h
27#define ProcessThrottler_h
28
29#include "ProcessAssertion.h"
30
31#include <wtf/ProcessID.h>
32#include <wtf/RefCounter.h>
33#include <wtf/RunLoop.h>
34#include <wtf/WeakPtr.h>
35
36namespace WebKit {
37
38enum UserObservablePageCounterType { };
39typedef RefCounter<UserObservablePageCounterType> UserObservablePageCounter;
40enum ProcessSuppressionDisabledCounterType { };
41typedef RefCounter<ProcessSuppressionDisabledCounterType> ProcessSuppressionDisabledCounter;
42typedef ProcessSuppressionDisabledCounter::Token ProcessSuppressionDisabledToken;
43
44class ProcessThrottlerClient;
45
46class ProcessThrottler : private ProcessAssertion::Client {
47public:
48 enum ForegroundActivityCounterType { };
49 typedef RefCounter<ForegroundActivityCounterType> ForegroundActivityCounter;
50 typedef ForegroundActivityCounter::Token ForegroundActivityToken;
51 enum BackgroundActivityCounterType { };
52 typedef RefCounter<BackgroundActivityCounterType> BackgroundActivityCounter;
53 typedef BackgroundActivityCounter::Token BackgroundActivityToken;
54
55 ProcessThrottler(ProcessThrottlerClient&, bool shouldTakeUIBackgroundAssertion);
56
57 inline ForegroundActivityToken foregroundActivityToken() const;
58 inline BackgroundActivityToken backgroundActivityToken() const;
59
60 void didConnectToProcess(ProcessID);
61 void processReadyToSuspend();
62 void didCancelProcessSuspension();
63 bool shouldBeRunnable() const { return m_foregroundCounter.value() || m_backgroundCounter.value(); }
64
65private:
66 AssertionState assertionState();
67 void updateAssertion();
68 void updateAssertionNow();
69 void suspendTimerFired();
70
71 // ProcessAssertionClient
72 void uiAssertionWillExpireImminently() override;
73
74 ProcessThrottlerClient& m_process;
75 std::unique_ptr<ProcessAssertion> m_assertion;
76 RunLoop::Timer<ProcessThrottler> m_suspendTimer;
77 ForegroundActivityCounter m_foregroundCounter;
78 BackgroundActivityCounter m_backgroundCounter;
79 int m_suspendMessageCount { 0 };
80 bool m_shouldTakeUIBackgroundAssertion;
81 bool m_uiAssertionExpired { false };
82};
83
84inline ProcessThrottler::ForegroundActivityToken ProcessThrottler::foregroundActivityToken() const
85{
86 return ForegroundActivityToken(m_foregroundCounter.count());
87}
88
89inline ProcessThrottler::BackgroundActivityToken ProcessThrottler::backgroundActivityToken() const
90{
91 return BackgroundActivityToken(m_backgroundCounter.count());
92}
93
94}
95
96#endif // ProcessThrottler_h
97