src/hb-atomic.hh - platform/external/harfbuzz_ng - Git at Google

 /*
  * 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 <[email protected]>
  * 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 */
	/*
	* 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 <[email protected]>
	* 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 */