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
225
226
227
228
|
/*
* Copyright © 2007 Chris Wilson
* Copyright © 2009,2010 Red Hat, Inc.
* Copyright © 2011,2012 Google, Inc.
*
* This is part of HarfBuzz, a text shaping library.
*
* Permission is hereby granted, without written agreement and without
* license or royalty fees, to use, copy, modify, and distribute this
* software and its documentation for any purpose, provided that the
* above copyright notice and the following two paragraphs appear in
* all copies of this software.
*
* IN NO EVENT SHALL THE COPYRIGHT HOLDER BE LIABLE TO ANY PARTY FOR
* DIRECT, INDIRECT, SPECIAL, INCIDENTAL, OR CONSEQUENTIAL DAMAGES
* ARISING OUT OF THE USE OF THIS SOFTWARE AND ITS DOCUMENTATION, EVEN
* IF THE COPYRIGHT HOLDER HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH
* DAMAGE.
*
* THE COPYRIGHT HOLDER SPECIFICALLY DISCLAIMS ANY WARRANTIES, INCLUDING,
* BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND
* FITNESS FOR A PARTICULAR PURPOSE. THE SOFTWARE PROVIDED HEREUNDER IS
* ON AN "AS IS" BASIS, AND THE COPYRIGHT HOLDER HAS NO OBLIGATION TO
* PROVIDE MAINTENANCE, SUPPORT, UPDATES, ENHANCEMENTS, OR MODIFICATIONS.
*
* Contributor(s):
* Chris Wilson <chris@chris-wilson.co.uk>
* Red Hat Author(s): Behdad Esfahbod
* Google Author(s): Behdad Esfahbod
*/
#ifndef HB_ATOMIC_HH
#define HB_ATOMIC_HH
#include "hb.hh"
#include "hb-meta.hh"
/*
* Atomic integers and pointers.
*/
/* We need external help for these */
#if defined(hb_atomic_int_impl_add) \
&& defined(hb_atomic_ptr_impl_get) \
&& defined(hb_atomic_ptr_impl_cmpexch)
/* Defined externally, i.e. in config.h. */
#elif !defined(HB_NO_MT) && defined(__ATOMIC_ACQUIRE)
/* C++11-style GCC primitives. We prefer these as they don't require linking to libstdc++ / libc++. */
#define _hb_memory_barrier() __sync_synchronize ()
#define hb_atomic_int_impl_add(AI, V) __atomic_fetch_add ((AI), (V), __ATOMIC_ACQ_REL)
#define hb_atomic_int_impl_set_relaxed(AI, V) __atomic_store_n ((AI), (V), __ATOMIC_RELAXED)
#define hb_atomic_int_impl_set(AI, V) __atomic_store_n ((AI), (V), __ATOMIC_RELEASE)
#define hb_atomic_int_impl_get_relaxed(AI) __atomic_load_n ((AI), __ATOMIC_RELAXED)
#define hb_atomic_int_impl_get(AI) __atomic_load_n ((AI), __ATOMIC_ACQUIRE)
#define hb_atomic_ptr_impl_set_relaxed(P, V) __atomic_store_n ((P), (V), __ATOMIC_RELAXED)
#define hb_atomic_ptr_impl_get_relaxed(P) __atomic_load_n ((P), __ATOMIC_RELAXED)
#define hb_atomic_ptr_impl_get(P) __atomic_load_n ((P), __ATOMIC_ACQUIRE)
static inline bool
_hb_atomic_ptr_impl_cmplexch (const void **P, const void *O_, const void *N)
{
const void *O = O_; // Need lvalue
return __atomic_compare_exchange_n ((void **) P, (void **) &O, (void *) N, true, __ATOMIC_ACQ_REL, __ATOMIC_RELAXED);
}
#define hb_atomic_ptr_impl_cmpexch(P,O,N) _hb_atomic_ptr_impl_cmplexch ((const void **) (P), (O), (N))
#elif !defined(HB_NO_MT)
/* C++11 atomics. */
#include <atomic>
#define _hb_memory_barrier() std::atomic_thread_fence(std::memory_order_ack_rel)
#define _hb_memory_r_barrier() std::atomic_thread_fence(std::memory_order_acquire)
#define _hb_memory_w_barrier() std::atomic_thread_fence(std::memory_order_release)
#define hb_atomic_int_impl_add(AI, V) (reinterpret_cast<std::atomic<std::decay<decltype (*(AI))>::type> *> (AI)->fetch_add ((V), std::memory_order_acq_rel))
#define hb_atomic_int_impl_set_relaxed(AI, V) (reinterpret_cast<std::atomic<std::decay<decltype (*(AI))>::type> *> (AI)->store ((V), std::memory_order_relaxed))
#define hb_atomic_int_impl_set(AI, V) (reinterpret_cast<std::atomic<std::decay<decltype (*(AI))>::type> *> (AI)->store ((V), std::memory_order_release))
#define hb_atomic_int_impl_get_relaxed(AI) (reinterpret_cast<std::atomic<std::decay<decltype (*(AI))>::type> const *> (AI)->load (std::memory_order_relaxed))
#define hb_atomic_int_impl_get(AI) (reinterpret_cast<std::atomic<std::decay<decltype (*(AI))>::type> const *> (AI)->load (std::memory_order_acquire))
#define hb_atomic_ptr_impl_set_relaxed(P, V) (reinterpret_cast<std::atomic<void*> *> (P)->store ((V), std::memory_order_relaxed))
#define hb_atomic_ptr_impl_get_relaxed(P) (reinterpret_cast<std::atomic<void*> const *> (P)->load (std::memory_order_relaxed))
#define hb_atomic_ptr_impl_get(P) (reinterpret_cast<std::atomic<void*> *> (P)->load (std::memory_order_acquire))
static inline bool
_hb_atomic_ptr_impl_cmplexch (const void **P, const void *O_, const void *N)
{
const void *O = O_; // Need lvalue
return reinterpret_cast<std::atomic<const void*> *> (P)->compare_exchange_weak (O, N, std::memory_order_acq_rel, std::memory_order_relaxed);
}
#define hb_atomic_ptr_impl_cmpexch(P,O,N) _hb_atomic_ptr_impl_cmplexch ((const void **) (P), (O), (N))
#else /* defined(HB_NO_MT) */
#define hb_atomic_int_impl_add(AI, V) ((*(AI) += (V)) - (V))
#define _hb_memory_barrier() do {} while (0)
#define hb_atomic_ptr_impl_cmpexch(P,O,N) (* (void **) (P) == (void *) (O) ? (* (void **) (P) = (void *) (N), true) : false)
#endif
/* This should never be disabled, even under HB_NO_MT.
* except that MSVC gives me an internal compiler error, so disabled there.
*
* https://github.com/harfbuzz/harfbuzz/pull/4119
*/
#ifndef _hb_compiler_memory_r_barrier
#if defined(__ATOMIC_ACQUIRE) // gcc-like
static inline void _hb_compiler_memory_r_barrier () { asm volatile("": : :"memory"); }
#elif !defined(_MSC_VER)
#include <atomic>
#define _hb_compiler_memory_r_barrier() std::atomic_signal_fence (std::memory_order_acquire)
#else
static inline void _hb_compiler_memory_r_barrier () {}
#endif
#endif
#ifndef _hb_memory_r_barrier
#define _hb_memory_r_barrier() _hb_memory_barrier ()
#endif
#ifndef _hb_memory_w_barrier
#define _hb_memory_w_barrier() _hb_memory_barrier ()
#endif
#ifndef hb_atomic_int_impl_set_relaxed
#define hb_atomic_int_impl_set_relaxed(AI, V) (*(AI) = (V))
#endif
#ifndef hb_atomic_int_impl_get_relaxed
#define hb_atomic_int_impl_get_relaxed(AI) (*(AI))
#endif
#ifndef hb_atomic_ptr_impl_set_relaxed
#define hb_atomic_ptr_impl_set_relaxed(P, V) (*(P) = (V))
#endif
#ifndef hb_atomic_ptr_impl_get_relaxed
#define hb_atomic_ptr_impl_get_relaxed(P) (*(P))
#endif
#ifndef hb_atomic_int_impl_set
inline void hb_atomic_int_impl_set (int *AI, int v) { _hb_memory_w_barrier (); *AI = v; }
inline void hb_atomic_int_impl_set (short *AI, short v) { _hb_memory_w_barrier (); *AI = v; }
#endif
#ifndef hb_atomic_int_impl_get
inline int hb_atomic_int_impl_get (const int *AI) { int v = *AI; _hb_memory_r_barrier (); return v; }
inline short hb_atomic_int_impl_get (const short *AI) { short v = *AI; _hb_memory_r_barrier (); return v; }
#endif
#ifndef hb_atomic_ptr_impl_get
inline void *hb_atomic_ptr_impl_get (void ** const P) { void *v = *P; _hb_memory_r_barrier (); return v; }
#endif
struct hb_atomic_short_t
{
hb_atomic_short_t () = default;
constexpr hb_atomic_short_t (short v) : v (v) {}
hb_atomic_short_t& operator = (short v_) { set_relaxed (v_); return *this; }
operator short () const { return get_relaxed (); }
void set_relaxed (short v_) { hb_atomic_int_impl_set_relaxed (&v, v_); }
void set_release (short v_) { hb_atomic_int_impl_set (&v, v_); }
short get_relaxed () const { return hb_atomic_int_impl_get_relaxed (&v); }
short get_acquire () const { return hb_atomic_int_impl_get (&v); }
short inc () { return hb_atomic_int_impl_add (&v, 1); }
short dec () { return hb_atomic_int_impl_add (&v, -1); }
short v = 0;
};
struct hb_atomic_int_t
{
hb_atomic_int_t () = default;
constexpr hb_atomic_int_t (int v) : v (v) {}
hb_atomic_int_t& operator = (int v_) { set_relaxed (v_); return *this; }
operator int () const { return get_relaxed (); }
void set_relaxed (int v_) { hb_atomic_int_impl_set_relaxed (&v, v_); }
void set_release (int v_) { hb_atomic_int_impl_set (&v, v_); }
int get_relaxed () const { return hb_atomic_int_impl_get_relaxed (&v); }
int get_acquire () const { return hb_atomic_int_impl_get (&v); }
int inc () { return hb_atomic_int_impl_add (&v, 1); }
int dec () { return hb_atomic_int_impl_add (&v, -1); }
int v = 0;
};
template <typename P>
struct hb_atomic_ptr_t
{
typedef hb_remove_pointer<P> T;
hb_atomic_ptr_t () = default;
constexpr hb_atomic_ptr_t (T* v) : v (v) {}
hb_atomic_ptr_t (const hb_atomic_ptr_t &other) = delete;
void init (T* v_ = nullptr) { set_relaxed (v_); }
void set_relaxed (T* v_) { hb_atomic_ptr_impl_set_relaxed (&v, v_); }
T *get_relaxed () const { return (T *) hb_atomic_ptr_impl_get_relaxed (&v); }
T *get_acquire () const { return (T *) hb_atomic_ptr_impl_get ((void **) &v); }
bool cmpexch (const T *old, T *new_) const { return hb_atomic_ptr_impl_cmpexch ((void **) &v, (void *) old, (void *) new_); }
T * operator -> () const { return get_acquire (); }
template <typename C> operator C * () const { return get_acquire (); }
T *v = nullptr;
};
static inline bool hb_barrier ()
{
_hb_compiler_memory_r_barrier ();
return true;
}
#endif /* HB_ATOMIC_HH */
|
