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1 | ///////////////////////////////////////////////////////////////////////////// |
2 | // Name: wx/atomic.h | |
3 | // Purpose: functions to manipulate atomically integers and pointers | |
4 | // Author: Armel Asselin | |
5 | // Created: 12/13/2006 | |
cde76cf2 VZ |
6 | // Copyright: (c) Armel Asselin |
7 | // Licence: wxWindows licence | |
8 | ///////////////////////////////////////////////////////////////////////////// | |
9 | ||
10 | #ifndef _WX_ATOMIC_H_ | |
11 | #define _WX_ATOMIC_H_ | |
12 | ||
13 | // ---------------------------------------------------------------------------- | |
14 | // headers | |
15 | // ---------------------------------------------------------------------------- | |
16 | ||
17 | // get the value of wxUSE_THREADS configuration flag | |
18 | #include "wx/defs.h" | |
19 | ||
20 | // constraints on the various functions: | |
21 | // - wxAtomicDec must return a zero value if the value is zero once | |
22 | // decremented else it must return any non-zero value (the true value is OK | |
23 | // but not necessary). | |
24 | ||
25 | #if wxUSE_THREADS | |
26 | ||
47964710 | 27 | #if defined(HAVE_GCC_ATOMIC_BUILTINS) |
cde76cf2 | 28 | |
47964710 VS |
29 | // NB: we intentionally don't use Linux's asm/atomic.h header, because it's |
30 | // an internal kernel header that doesn't always work in userspace: | |
31 | // http://bugs.mysql.com/bug.php?id=28456 | |
32 | // http://golubenco.org/blog/atomic-operations/ | |
cde76cf2 VZ |
33 | |
34 | inline void wxAtomicInc (wxUint32 &value) | |
35 | { | |
47964710 | 36 | __sync_fetch_and_add(&value, 1); |
cde76cf2 VZ |
37 | } |
38 | ||
39 | inline wxUint32 wxAtomicDec (wxUint32 &value) | |
40 | { | |
47964710 | 41 | return __sync_sub_and_fetch(&value, 1); |
cde76cf2 VZ |
42 | } |
43 | ||
cde76cf2 | 44 | |
bb5a9514 | 45 | #elif defined(__WINDOWS__) |
47964710 VS |
46 | |
47 | // include standard Windows headers | |
48 | #include "wx/msw/wrapwin.h" | |
49 | ||
cde76cf2 VZ |
50 | inline void wxAtomicInc (wxUint32 &value) |
51 | { | |
47964710 | 52 | InterlockedIncrement ((LONG*)&value); |
cde76cf2 VZ |
53 | } |
54 | ||
55 | inline wxUint32 wxAtomicDec (wxUint32 &value) | |
56 | { | |
47964710 | 57 | return InterlockedDecrement ((LONG*)&value); |
cde76cf2 VZ |
58 | } |
59 | ||
47964710 | 60 | #elif defined(__WXMAC__) || defined(__DARWIN__) |
cde76cf2 | 61 | |
47964710 | 62 | #include "libkern/OSAtomic.h" |
cde76cf2 VZ |
63 | inline void wxAtomicInc (wxUint32 &value) |
64 | { | |
47964710 | 65 | OSAtomicIncrement32 ((int32_t*)&value); |
cde76cf2 VZ |
66 | } |
67 | ||
68 | inline wxUint32 wxAtomicDec (wxUint32 &value) | |
69 | { | |
47964710 | 70 | return OSAtomicDecrement32 ((int32_t*)&value); |
cde76cf2 VZ |
71 | } |
72 | ||
73 | #elif defined (__SOLARIS__) | |
74 | ||
75 | #include <atomic.h> | |
76 | ||
77 | inline void wxAtomicInc (wxUint32 &value) | |
78 | { | |
79 | atomic_add_32 ((uint32_t*)&value, 1); | |
80 | } | |
81 | ||
82 | inline wxUint32 wxAtomicDec (wxUint32 &value) | |
83 | { | |
84 | return atomic_add_32_nv ((uint32_t*)&value, (uint32_t)-1); | |
85 | } | |
86 | ||
87 | #else // unknown platform | |
88 | ||
89 | // it will result in inclusion if the generic implementation code a bit later in this page | |
42124e68 | 90 | #define wxNEEDS_GENERIC_ATOMIC_OPS |
cde76cf2 VZ |
91 | |
92 | #endif // unknown platform | |
93 | ||
94 | #else // else of wxUSE_THREADS | |
95 | // if no threads are used we can safely use simple ++/-- | |
96 | ||
97 | inline void wxAtomicInc (wxUint32 &value) { ++value; } | |
98 | inline wxUint32 wxAtomicDec (wxUint32 &value) { return --value; } | |
99 | ||
100 | #endif // !wxUSE_THREADS | |
101 | ||
102 | // ---------------------------------------------------------------------------- | |
103 | // proxies to actual implementations, but for various other types with same | |
104 | // behaviour | |
105 | // ---------------------------------------------------------------------------- | |
106 | ||
42124e68 | 107 | #ifdef wxNEEDS_GENERIC_ATOMIC_OPS |
cde76cf2 | 108 | |
cde76cf2 VZ |
109 | #include "wx/thread.h" // for wxCriticalSection |
110 | ||
111 | class wxAtomicInt32 | |
112 | { | |
113 | public: | |
eb096b8e VS |
114 | wxAtomicInt32() { } // non initialized for consistency with basic int type |
115 | wxAtomicInt32(wxInt32 v) : m_value(v) { } | |
bc1d617a | 116 | wxAtomicInt32(const wxAtomicInt32& a) : m_value(a.m_value) {} |
cde76cf2 VZ |
117 | |
118 | operator wxInt32() const { return m_value; } | |
eb096b8e | 119 | operator volatile wxInt32&() { return m_value; } |
cde76cf2 | 120 | |
eb096b8e | 121 | wxAtomicInt32& operator=(wxInt32 v) { m_value = v; return *this; } |
cde76cf2 VZ |
122 | |
123 | void Inc() | |
124 | { | |
125 | wxCriticalSectionLocker lock(m_locker); | |
126 | ++m_value; | |
127 | } | |
128 | ||
129 | wxInt32 Dec() | |
130 | { | |
131 | wxCriticalSectionLocker lock(m_locker); | |
132 | return --m_value; | |
133 | } | |
134 | ||
135 | private: | |
136 | volatile wxInt32 m_value; | |
137 | wxCriticalSection m_locker; | |
138 | }; | |
139 | ||
eb096b8e VS |
140 | inline void wxAtomicInc(wxAtomicInt32 &value) { value.Inc(); } |
141 | inline wxInt32 wxAtomicDec(wxAtomicInt32 &value) { return value.Dec(); } | |
cde76cf2 | 142 | |
42124e68 VZ |
143 | #else // !wxNEEDS_GENERIC_ATOMIC_OPS |
144 | ||
145 | #define wxHAS_ATOMIC_OPS | |
cde76cf2 VZ |
146 | |
147 | inline void wxAtomicInc(wxInt32 &value) { wxAtomicInc((wxUint32&)value); } | |
148 | inline wxInt32 wxAtomicDec(wxInt32 &value) { return wxAtomicDec((wxUint32&)value); } | |
149 | ||
150 | typedef wxInt32 wxAtomicInt32; | |
151 | ||
42124e68 | 152 | #endif // wxNEEDS_GENERIC_ATOMIC_OPS |
cde76cf2 VZ |
153 | |
154 | // all the native implementations use 32 bits currently | |
155 | // for a 64 bits implementation we could use (a future) wxAtomicInt64 as | |
156 | // default type | |
157 | typedef wxAtomicInt32 wxAtomicInt; | |
158 | ||
159 | #endif // _WX_ATOMIC_H_ |