1 /*
   2  * Copyright © 2007  Chris Wilson
   3  * Copyright © 2009,2010  Red Hat, Inc.
   4  * Copyright © 2011,2012  Google, Inc.
   5  *
   6  *  This is part of HarfBuzz, a text shaping library.
   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 HB_ATOMIC_HH
  33 #define HB_ATOMIC_HH
  34 
  35 #include "hb.hh"
  36 
  37 
  38 /*
  39  * Atomic integers and pointers.
  40  */
  41 
  42 
  43 /* We need external help for these */
  44 
  45 #if defined(hb_atomic_int_impl_add) \
  46  && defined(hb_atomic_ptr_impl_get) \
  47  && defined(hb_atomic_ptr_impl_cmpexch)
  48 
  49 /* Defined externally, i.e. in config.h. */
  50 
  51 
  52 #elif !defined(HB_NO_MT) && defined(__ATOMIC_ACQUIRE)
  53 
  54 /* C++11-style GCC primitives. */
  55 
  56 #define _hb_memory_barrier()                    __sync_synchronize ()
  57 
  58 #define hb_atomic_int_impl_add(AI, V)           __atomic_fetch_add ((AI), (V), __ATOMIC_ACQ_REL)
  59 #define hb_atomic_int_impl_set_relaxed(AI, V)   __atomic_store_n ((AI), (V), __ATOMIC_RELAXED)
  60 #define hb_atomic_int_impl_set(AI, V)           __atomic_store_n ((AI), (V), __ATOMIC_RELEASE)
  61 #define hb_atomic_int_impl_get_relaxed(AI)      __atomic_load_n ((AI), __ATOMIC_RELAXED)
  62 #define hb_atomic_int_impl_get(AI)              __atomic_load_n ((AI), __ATOMIC_ACQUIRE)
  63 
  64 #define hb_atomic_ptr_impl_set_relaxed(P, V)    __atomic_store_n ((P), (V), __ATOMIC_RELAXED)
  65 #define hb_atomic_ptr_impl_get_relaxed(P)       __atomic_load_n ((P), __ATOMIC_RELAXED)
  66 #define hb_atomic_ptr_impl_get(P)               __atomic_load_n ((P), __ATOMIC_ACQUIRE)
  67 static inline bool
  68 _hb_atomic_ptr_impl_cmplexch (const void **P, const void *O_, const void *N)
  69 {
  70   const void *O = O_; // Need lvalue
  71   return __atomic_compare_exchange_n ((void **) P, (void **) &O, (void *) N, true, __ATOMIC_ACQ_REL, __ATOMIC_RELAXED);
  72 }
  73 #define hb_atomic_ptr_impl_cmpexch(P,O,N)       _hb_atomic_ptr_impl_cmplexch ((const void **) (P), (O), (N))
  74 
  75 #elif !defined(HB_NO_MT) && __cplusplus >= 201103L
  76 
  77 /* C++11 atomics. */
  78 
  79 #include <atomic>
  80 
  81 #define _hb_memory_barrier()                    std::atomic_thread_fence(std::memory_order_ack_rel)
  82 #define _hb_memory_r_barrier()                  std::atomic_thread_fence(std::memory_order_acquire)
  83 #define _hb_memory_w_barrier()                  std::atomic_thread_fence(std::memory_order_release)
  84 
  85 #define hb_atomic_int_impl_add(AI, V)           (reinterpret_cast<std::atomic<int> *> (AI)->fetch_add ((V), std::memory_order_acq_rel))
  86 #define hb_atomic_int_impl_set_relaxed(AI, V)   (reinterpret_cast<std::atomic<int> *> (AI)->store ((V), std::memory_order_relaxed))
  87 #define hb_atomic_int_impl_set(AI, V)           (reinterpret_cast<std::atomic<int> *> (AI)->store ((V), std::memory_order_release))
  88 #define hb_atomic_int_impl_get_relaxed(AI)      (reinterpret_cast<std::atomic<int> *> (AI)->load (std::memory_order_relaxed))
  89 #define hb_atomic_int_impl_get(AI)              (reinterpret_cast<std::atomic<int> *> (AI)->load (std::memory_order_acquire))
  90 
  91 #define hb_atomic_ptr_impl_set_relaxed(P, V)    (reinterpret_cast<std::atomic<void*> *> (P)->store ((V), std::memory_order_relaxed))
  92 #define hb_atomic_ptr_impl_get_relaxed(P)       (reinterpret_cast<std::atomic<void*> *> (P)->load (std::memory_order_relaxed))
  93 #define hb_atomic_ptr_impl_get(P)               (reinterpret_cast<std::atomic<void*> *> (P)->load (std::memory_order_acquire))
  94 static inline bool
  95 _hb_atomic_ptr_impl_cmplexch (const void **P, const void *O_, const void *N)
  96 {
  97   const void *O = O_; // Need lvalue
  98   return reinterpret_cast<std::atomic<const void*> *> (P)->compare_exchange_weak (O, N, std::memory_order_acq_rel, std::memory_order_relaxed);
  99 }
 100 #define hb_atomic_ptr_impl_cmpexch(P,O,N)       _hb_atomic_ptr_impl_cmplexch ((const void **) (P), (O), (N))
 101 
 102 
 103 #elif !defined(HB_NO_MT) && defined(_WIN32)
 104 
 105 #include <windows.h>
 106 
 107 static inline void _hb_memory_barrier ()
 108 {
 109 #if !defined(MemoryBarrier)
 110   /* MinGW has a convoluted history of supporting MemoryBarrier. */
 111   LONG dummy = 0;
 112   InterlockedExchange (&dummy, 1);
 113 #else
 114   MemoryBarrier ();
 115 #endif
 116 }
 117 #define _hb_memory_barrier()                    _hb_memory_barrier ()
 118 
 119 #define hb_atomic_int_impl_add(AI, V)           InterlockedExchangeAdd ((LONG *) (AI), (V))
 120 static_assert ((sizeof (LONG) == sizeof (int)), "");
 121 
 122 #define hb_atomic_ptr_impl_cmpexch(P,O,N)       (InterlockedCompareExchangePointer ((P), (N), (O)) == (O))
 123 
 124 
 125 #elif !defined(HB_NO_MT) && defined(HAVE_INTEL_ATOMIC_PRIMITIVES)
 126 
 127 #define _hb_memory_barrier()                    __sync_synchronize ()
 128 
 129 #define hb_atomic_int_impl_add(AI, V)           __sync_fetch_and_add ((AI), (V))
 130 
 131 #define hb_atomic_ptr_impl_cmpexch(P,O,N)       __sync_bool_compare_and_swap ((P), (O), (N))
 132 
 133 
 134 #elif !defined(HB_NO_MT) && defined(HAVE_SOLARIS_ATOMIC_OPS)
 135 
 136 #include <atomic.h>
 137 #include <mbarrier.h>
 138 
 139 #define _hb_memory_r_barrier()                  __machine_r_barrier ()
 140 #define _hb_memory_w_barrier()                  __machine_w_barrier ()
 141 #define _hb_memory_barrier()                    __machine_rw_barrier ()
 142 
 143 static inline int _hb_fetch_and_add (int *AI, int V)
 144 {
 145   _hb_memory_w_barrier ();
 146   int result = atomic_add_int_nv ((uint_t *) AI, V) - V;
 147   _hb_memory_r_barrier ();
 148   return result;
 149 }
 150 static inline bool _hb_compare_and_swap_ptr (void **P, void *O, void *N)
 151 {
 152   _hb_memory_w_barrier ();
 153   bool result = atomic_cas_ptr (P, O, N) == O;
 154   _hb_memory_r_barrier ();
 155   return result;
 156 }
 157 
 158 #define hb_atomic_int_impl_add(AI, V)           _hb_fetch_and_add ((AI), (V))
 159 
 160 #define hb_atomic_ptr_impl_cmpexch(P,O,N)       _hb_compare_and_swap_ptr ((P), (O), (N))
 161 
 162 
 163 #elif !defined(HB_NO_MT) && defined(__APPLE__)
 164 
 165 #include <libkern/OSAtomic.h>
 166 #ifdef __MAC_OS_X_MIN_REQUIRED
 167 #include <AvailabilityMacros.h>
 168 #elif defined(__IPHONE_OS_MIN_REQUIRED)
 169 #include <Availability.h>
 170 #endif
 171 
 172 #define _hb_memory_barrier()                    OSMemoryBarrier ()
 173 
 174 #define hb_atomic_int_impl_add(AI, V)           (OSAtomicAdd32Barrier ((V), (AI)) - (V))
 175 
 176 #if (MAC_OS_X_VERSION_MIN_REQUIRED > MAC_OS_X_VERSION_10_4 || __IPHONE_VERSION_MIN_REQUIRED >= 20100)
 177 #define hb_atomic_ptr_impl_cmpexch(P,O,N)       OSAtomicCompareAndSwapPtrBarrier ((O), (N), (P))
 178 #else
 179 #if __ppc64__ || __x86_64__ || __aarch64__
 180 #define hb_atomic_ptr_impl_cmpexch(P,O,N)       OSAtomicCompareAndSwap64Barrier ((int64_t) (O), (int64_t) (N), (int64_t*) (P))
 181 #else
 182 #define hb_atomic_ptr_impl_cmpexch(P,O,N)       OSAtomicCompareAndSwap32Barrier ((int32_t) (O), (int32_t) (N), (int32_t*) (P))
 183 #endif
 184 #endif
 185 
 186 
 187 #elif !defined(HB_NO_MT) && defined(_AIX) && (defined(__IBMCPP__) || defined(__ibmxl__))
 188 
 189 #include <builtins.h>
 190 
 191 #define _hb_memory_barrier()                    __lwsync ()
 192 
 193 static inline int _hb_fetch_and_add (int *AI, int V)
 194 {
 195   _hb_memory_barrier ();
 196   int result = __fetch_and_add (AI, V);
 197   _hb_memory_barrier ();
 198   return result;
 199 }
 200 static inline bool _hb_compare_and_swaplp (long *P, long O, long N)
 201 {
 202   _hb_memory_barrier ();
 203   bool result = __compare_and_swaplp (P, &O, N);
 204   _hb_memory_barrier ();
 205   return result;
 206 }
 207 
 208 #define hb_atomic_int_impl_add(AI, V)           _hb_fetch_and_add ((AI), (V))
 209 
 210 #define hb_atomic_ptr_impl_cmpexch(P,O,N)       _hb_compare_and_swaplp ((long *) (P), (long) (O), (long) (N))
 211 static_assert ((sizeof (long) == sizeof (void *)), "");
 212 
 213 
 214 #elif !defined(HB_NO_MT)
 215 
 216 #define HB_ATOMIC_INT_NIL 1 /* Warn that fallback implementation is in use. */
 217 
 218 #define _hb_memory_barrier()
 219 
 220 #define hb_atomic_int_impl_add(AI, V)           ((*(AI) += (V)) - (V))
 221 
 222 #define hb_atomic_ptr_impl_cmpexch(P,O,N)       (* (void **) (P) == (void *) (O) ? (* (void **) (P) = (void *) (N), true) : false)
 223 
 224 
 225 #else /* HB_NO_MT */
 226 
 227 #define hb_atomic_int_impl_add(AI, V)           ((*(AI) += (V)) - (V))
 228 
 229 #define _hb_memory_barrier()
 230 
 231 #define hb_atomic_ptr_impl_cmpexch(P,O,N)       (* (void **) (P) == (void *) (O) ? (* (void **) (P) = (void *) (N), true) : false)
 232 
 233 
 234 #endif
 235 
 236 
 237 #ifndef _hb_memory_r_barrier
 238 #define _hb_memory_r_barrier()                  _hb_memory_barrier ()
 239 #endif
 240 #ifndef _hb_memory_w_barrier
 241 #define _hb_memory_w_barrier()                  _hb_memory_barrier ()
 242 #endif
 243 #ifndef hb_atomic_int_impl_set_relaxed
 244 #define hb_atomic_int_impl_set_relaxed(AI, V)   (*(AI) = (V))
 245 #endif
 246 #ifndef hb_atomic_int_impl_get_relaxed
 247 #define hb_atomic_int_impl_get_relaxed(AI)      (*(AI))
 248 #endif
 249 
 250 #ifndef hb_atomic_ptr_impl_set_relaxed
 251 #define hb_atomic_ptr_impl_set_relaxed(P, V)    (*(P) = (V))
 252 #endif
 253 #ifndef hb_atomic_ptr_impl_get_relaxed
 254 #define hb_atomic_ptr_impl_get_relaxed(P)       (*(P))
 255 #endif
 256 #ifndef hb_atomic_int_impl_set
 257 inline void hb_atomic_int_impl_set (int *AI, int v)     { _hb_memory_w_barrier (); *AI = v; }
 258 #endif
 259 #ifndef hb_atomic_int_impl_get
 260 inline int hb_atomic_int_impl_get (const int *AI)       { int v = *AI; _hb_memory_r_barrier (); return v; }
 261 #endif
 262 #ifndef hb_atomic_ptr_impl_get
 263 inline void *hb_atomic_ptr_impl_get (void ** const P)   { void *v = *P; _hb_memory_r_barrier (); return v; }
 264 #endif
 265 
 266 
 267 #define HB_ATOMIC_INT_INIT(V)          {V}
 268 struct hb_atomic_int_t
 269 {
 270   void set_relaxed (int v_) { hb_atomic_int_impl_set_relaxed (&v, v_); }
 271   void set (int v_) { hb_atomic_int_impl_set (&v, v_); }
 272   int get_relaxed () const { return hb_atomic_int_impl_get_relaxed (&v); }
 273   int get () const { return hb_atomic_int_impl_get (&v); }
 274   int inc () { return hb_atomic_int_impl_add (&v,  1); }
 275   int dec () { return hb_atomic_int_impl_add (&v, -1); }
 276 
 277   int v;
 278 };
 279 
 280 
 281 #define HB_ATOMIC_PTR_INIT(V)          {V}
 282 template <typename P>
 283 struct hb_atomic_ptr_t
 284 {
 285   typedef typename hb_remove_pointer (P) T;
 286 
 287   void init (T* v_ = nullptr) { set_relaxed (v_); }
 288   void set_relaxed (T* v_) { hb_atomic_ptr_impl_set_relaxed (&v, v_); }
 289   T *get_relaxed () const { return (T *) hb_atomic_ptr_impl_get_relaxed (&v); }
 290   T *get () const { return (T *) hb_atomic_ptr_impl_get ((void **) &v); }
 291   bool cmpexch (const T *old, T *new_) const { return hb_atomic_ptr_impl_cmpexch ((void **) &v, (void *) old, (void *) new_); }
 292 
 293   T * operator -> () const                    { return get (); }
 294   template <typename C> operator C * () const { return get (); }
 295 
 296   T *v;
 297 };
 298 
 299 
 300 #endif /* HB_ATOMIC_HH */