1 /*
2 * Mutex operations. Originally copied from HarfBuzz.
3 *
4 * Copyright © 2007 Chris Wilson
5 * Copyright © 2009,2010 Red Hat, Inc.
6 * Copyright © 2011,2012,2013 Google, Inc.
7 *
8 * Permission is hereby granted, without written agreement and without
9 * license or royalty fees, to use, copy, modify, and distribute this
10 * software and its documentation for any purpose, provided that the
11 * above copyright notice and the following two paragraphs appear in
12 * all copies of this software.
13 *
14 * IN NO EVENT SHALL THE COPYRIGHT HOLDER BE LIABLE TO ANY PARTY FOR
15 * DIRECT, INDIRECT, SPECIAL, INCIDENTAL, OR CONSEQUENTIAL DAMAGES
16 * ARISING OUT OF THE USE OF THIS SOFTWARE AND ITS DOCUMENTATION, EVEN
17 * IF THE COPYRIGHT HOLDER HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH
18 * DAMAGE.
19 *
20 * THE COPYRIGHT HOLDER SPECIFICALLY DISCLAIMS ANY WARRANTIES, INCLUDING,
21 * BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND
22 * FITNESS FOR A PARTICULAR PURPOSE. THE SOFTWARE PROVIDED HEREUNDER IS
23 * ON AN "AS IS" BASIS, AND THE COPYRIGHT HOLDER HAS NO OBLIGATION TO
24 * PROVIDE MAINTENANCE, SUPPORT, UPDATES, ENHANCEMENTS, OR MODIFICATIONS.
25 *
26 * Contributor(s):
27 * Chris Wilson <chris@chris-wilson.co.uk>
28 * Red Hat Author(s): Behdad Esfahbod
29 * Google Author(s): Behdad Esfahbod
30 */
31
32 #ifndef _FCATOMIC_H_
33 #define _FCATOMIC_H_
34
35 #ifdef HAVE_CONFIG_H
36 #include <config.h>
37 #endif
38
39
40 /* atomic_int */
41
42 /* We need external help for these */
43
44 #if 0
45
46 typedef <type> fc_atomic_int_t;
47 #define FC_ATOMIC_INT_FORMAT "<printf format for fc_atomic_int_t>"
48 #define fc_atomic_int_add(AI, V) o = (AI), (AI) += (V), o // atomic acquire/release
49
50 #define fc_atomic_ptr_get(P) *(P) // atomic acquire
51 #define fc_atomic_ptr_cmpexch(P,O,N) *(P) == (O) ? (*(P) = (N), FcTrue) : FcFalse // atomic release
52
53
54 #elif !defined(FC_NO_MT) && defined(HAVE_STDATOMIC_PRIMITIVES)
55
56 #include <stdatomic.h>
57
58 typedef atomic_int fc_atomic_int_t;
59 #define FC_ATOMIC_INT_FORMAT "d"
60 #define fc_atomic_int_add(AI, V) atomic_fetch_add_explicit (&(AI), (V), memory_order_acq_rel)
61
62 #define fc_atomic_ptr_get(P) atomic_load_explicit ((_Atomic(void *)*) (P), memory_order_acquire)
63 static inline FcBool _fc_atomic_ptr_cmpexch(_Atomic(void *)*P, void * O, _Atomic(void *) N) {
64 return atomic_compare_exchange_strong_explicit(P, &O, N, memory_order_release, memory_order_relaxed);
65 }
66 #define fc_atomic_ptr_cmpexch(P,O,N) _fc_atomic_ptr_cmpexch ((_Atomic(void *)*) (P), (O), (N))
67
68 /* Casting -1 to _Atomic(int) produces a compiler error with Clang (but not GCC)
69 * so we have to override FC_REF_CONSTANT_VALUE for stdatomic.h atomics.
70 * See https://bugs.llvm.org/show_bug.cgi?id=40249. */
71 #define FC_REF_CONSTANT_VALUE (-1)
72
73 #elif !defined(FC_NO_MT) && defined(_MSC_VER) || defined(__MINGW32__)
74
75 #include "fcwindows.h"
76
77 typedef LONG fc_atomic_int_t;
78 #define FC_ATOMIC_INT_FORMAT "ld"
79 #define fc_atomic_int_add(AI, V) InterlockedExchangeAdd (&(AI), (V))
80
81 #define fc_atomic_ptr_get(P) (InterlockedCompareExchangePointerAcquire ((void **) (P), NULL, NULL))
82 #define fc_atomic_ptr_cmpexch(P,O,N) (InterlockedCompareExchangePointer ((void **) (P), (void *) (N), (void *) (O)) == (void *) (O))
83
84
85 #elif !defined(FC_NO_MT) && defined(__APPLE__)
86
87 #include <libkern/OSAtomic.h>
88 #include <AvailabilityMacros.h>
89
90 typedef int fc_atomic_int_t;
91 #define FC_ATOMIC_INT_FORMAT "d"
92 #define fc_atomic_int_add(AI, V) (OSAtomicAdd32Barrier ((V), &(AI)) - (V))
93
94 #if SIZEOF_VOID_P == 8
95 #define fc_atomic_ptr_get(P) OSAtomicAdd64Barrier (0, (int64_t*)(P))
96 #elif SIZEOF_VOID_P == 4
97 #define fc_atomic_ptr_get(P) OSAtomicAdd32Barrier (0, (int32_t*)(P))
98 #else
99 #error "SIZEOF_VOID_P not 4 or 8 (assumes CHAR_BIT is 8)"
100 #endif
101
102 #if (MAC_OS_X_VERSION_MIN_REQUIRED >= 1050 || __IPHONE_OS_VERSION_MIN_REQUIRED >= 20100)
103 #define fc_atomic_ptr_cmpexch(P,O,N) OSAtomicCompareAndSwapPtrBarrier ((void *) (O), (void *) (N), (void **) (P))
104 #else
105 #if __LP64__
106 #define fc_atomic_ptr_cmpexch(P,O,N) OSAtomicCompareAndSwap64Barrier ((int64_t) (O), (int64_t) (N), (int64_t *) (P))
107 #else
108 #define fc_atomic_ptr_cmpexch(P,O,N) OSAtomicCompareAndSwap32Barrier ((int32_t) (O), (int32_t) (N), (int32_t *) (P))
109 #endif
110 #endif
111
112
113 #elif !defined(FC_NO_MT) && defined(HAVE_INTEL_ATOMIC_PRIMITIVES)
114
115 typedef int fc_atomic_int_t;
116 #define FC_ATOMIC_INT_FORMAT "d"
117 #define fc_atomic_int_add(AI, V) __sync_fetch_and_add (&(AI), (V))
118
119 #define fc_atomic_ptr_get(P) (void *) (__sync_fetch_and_add ((P), 0))
120 #define fc_atomic_ptr_cmpexch(P,O,N) __sync_bool_compare_and_swap ((P), (O), (N))
121
122
123 #elif !defined(FC_NO_MT) && defined(HAVE_SOLARIS_ATOMIC_OPS)
124
125 #include <atomic.h>
126 #include <mbarrier.h>
127
128 typedef unsigned int fc_atomic_int_t;
129 #define FC_ATOMIC_INT_FORMAT "u"
130 #define fc_atomic_int_add(AI, V) ( ({__machine_rw_barrier ();}), atomic_add_int_nv (&(AI), (V)) - (V))
131
132 #define fc_atomic_ptr_get(P) ( ({__machine_rw_barrier ();}), (void *) *(P))
133 #define fc_atomic_ptr_cmpexch(P,O,N) ( ({__machine_rw_barrier ();}), atomic_cas_ptr ((P), (O), (N)) == (void *) (O) ? FcTrue : FcFalse)
134
135
136 #elif !defined(FC_NO_MT)
137
138 #define FC_ATOMIC_INT_NIL 1 /* Warn that fallback implementation is in use. */
139 typedef volatile int fc_atomic_int_t;
140 #define FC_ATOMIC_INT_FORMAT "d"
141 #define fc_atomic_int_add(AI, V) (((AI) += (V)) - (V))
142
143 #define fc_atomic_ptr_get(P) ((void *) *(P))
144 #define fc_atomic_ptr_cmpexch(P,O,N) (* (void * volatile *) (P) == (void *) (O) ? (* (void * volatile *) (P) = (void *) (N), FcTrue) : FcFalse)
145
146
147 #else /* FC_NO_MT */
148
149 typedef int fc_atomic_int_t;
150 #define FC_ATOMIC_INT_FORMAT "d"
151 #define fc_atomic_int_add(AI, V) (((AI) += (V)) - (V))
152
153 #define fc_atomic_ptr_get(P) ((void *) *(P))
154 #define fc_atomic_ptr_cmpexch(P,O,N) (* (void **) (P) == (void *) (O) ? (* (void **) (P) = (void *) (N), FcTrue) : FcFalse)
155
156 #endif
157
158 /* reference count */
159 #ifndef FC_REF_CONSTANT_VALUE
160 #define FC_REF_CONSTANT_VALUE ((fc_atomic_int_t) -1)
161 #endif
162 #define FC_REF_CONSTANT {FC_REF_CONSTANT_VALUE}
163 typedef struct _FcRef { fc_atomic_int_t count; } FcRef;
164 static inline void FcRefInit (FcRef *r, int v) { r->count = v; }
165 static inline int FcRefInc (FcRef *r) { return fc_atomic_int_add (r->count, +1); }
166 static inline int FcRefDec (FcRef *r) { return fc_atomic_int_add (r->count, -1); }
167 static inline int FcRefAdd (FcRef *r, int v) { return fc_atomic_int_add (r->count, v); }
168 static inline void FcRefSetConst (FcRef *r) { r->count = FC_REF_CONSTANT_VALUE; }
169 static inline FcBool FcRefIsConst (const FcRef *r) { return r->count == FC_REF_CONSTANT_VALUE; }
170
171 #endif /* _FCATOMIC_H_ */