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
|
/*
* Copyright (C) 2011 Apple 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 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.
*/
#ifndef MemoryPressureHandler_h
#define MemoryPressureHandler_h
#include <atomic>
#include <time.h>
#include <wtf/FastMalloc.h>
#if PLATFORM(IOS)
#include <wtf/ThreadingPrimitives.h>
#endif
namespace WebCore {
#if PLATFORM(IOS)
enum MemoryPressureReason {
MemoryPressureReasonNone = 0 << 0,
MemoryPressureReasonVMPressure = 1 << 0,
MemoryPressureReasonVMStatus = 1 << 1,
};
#endif
typedef void (*LowMemoryHandler)(bool critical);
class MemoryPressureHandler {
WTF_MAKE_FAST_ALLOCATED;
public:
friend MemoryPressureHandler& memoryPressureHandler();
WEBCORE_EXPORT void install();
void setLowMemoryHandler(LowMemoryHandler handler)
{
ASSERT(!m_installed);
m_lowMemoryHandler = handler;
}
bool isUnderMemoryPressure() const { return m_underMemoryPressure; }
void setUnderMemoryPressure(bool b) { m_underMemoryPressure = b; }
#if PLATFORM(IOS)
// FIXME: Can we share more of this with OpenSource?
WEBCORE_EXPORT void installMemoryReleaseBlock(void (^releaseMemoryBlock)(), bool clearPressureOnMemoryRelease = true);
WEBCORE_EXPORT void setReceivedMemoryPressure(MemoryPressureReason);
WEBCORE_EXPORT void clearMemoryPressure();
WEBCORE_EXPORT bool shouldWaitForMemoryClearMessage();
void respondToMemoryPressureIfNeeded();
#endif
class ReliefLogger {
public:
explicit ReliefLogger(const char *log)
: m_logString(log)
, m_initialMemory(s_loggingEnabled ? platformMemoryUsage() : 0)
{
}
~ReliefLogger()
{
if (s_loggingEnabled)
platformLog();
}
const char* logString() const { return m_logString; }
static void setLoggingEnabled(bool enabled) { s_loggingEnabled = enabled; }
static bool loggingEnabled() { return s_loggingEnabled; }
private:
size_t platformMemoryUsage();
void platformLog();
const char* m_logString;
size_t m_initialMemory;
static bool s_loggingEnabled;
};
WEBCORE_EXPORT static void releaseMemory(bool critical);
private:
static void releaseNoncriticalMemory();
static void releaseCriticalMemory();
void uninstall();
void holdOff(unsigned);
MemoryPressureHandler();
~MemoryPressureHandler();
void respondToMemoryPressure(bool critical);
static void platformReleaseMemory(bool critical);
bool m_installed;
time_t m_lastRespondTime;
LowMemoryHandler m_lowMemoryHandler;
std::atomic<bool> m_underMemoryPressure;
#if PLATFORM(IOS)
uint32_t m_memoryPressureReason;
bool m_clearPressureOnMemoryRelease;
void (^m_releaseMemoryBlock)();
CFRunLoopObserverRef m_observer;
Mutex m_observerMutex;
#endif
};
// Function to obtain the global memory pressure object.
WEBCORE_EXPORT MemoryPressureHandler& memoryPressureHandler();
} // namespace WebCore
#endif // MemoryPressureHandler_h
|
