| /* |
| * 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 |
| #define _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 |
| #define _hb_compiler_memory_r_barrier() do {} while (0) |
| #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; |
| }; |
| |
| |
| #endif /* HB_ATOMIC_HH */ |