*****************************************************************************
* Copyright (C) 2010 Rémi Denis-Courmont
*
- * This program is free software; you can redistribute it and/or modify
- * it under the terms of the GNU General Public License as published by
- * the Free Software Foundation; either version 2 of the License, or
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU Lesser General Public License as published by
+ * the Free Software Foundation; either version 2.1 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
- * GNU General Public License for more details.
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU Lesser General Public License for more details.
*
- * You should have received a copy of the GNU General Public License
- * along with this program; if not, write to the Free Software
- * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston MA 02110-1301, USA.
+ * You should have received a copy of the GNU Lesser General Public License
+ * along with this program; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin Street, Fifth Floor, Boston MA 02110-1301, USA.
*****************************************************************************/
#ifndef VLC_ATOMIC_H
* Atomic operations do not require locking, but they are not very powerful.
*/
-/**
- * Memory storage space for an atom. Never access it directly.
- */
-typedef union
-{
- uintptr_t u;
- intptr_t s;
-} vlc_atomic_t;
+# if !defined (__cplusplus) && (__STDC_VERSION__ >= 201112L) \
+ && !defined (__STDC_NO_ATOMICS__)
+
+/*** Native C11 atomics ***/
+# include <stdatomic.h>
+
+# else
+
+# define ATOMIC_FLAG_INIT false
+
+# define ATOMIC_VAR_INIT(value) (value)
+
+# define atomic_init(obj, value) \
+ do { *(obj) = (value); } while(0)
+
+# define kill_dependency(y) \
+ ((void)0)
+
+# define atomic_thread_fence(order) \
+ __sync_synchronize()
+
+# define atomic_signal_fence(order) \
+ ((void)0)
+
+# define atomic_is_lock_free(obj) \
+ false
+
+/* In principles, __sync_*() only supports int, long and long long and their
+ * unsigned equivalents, i.e. 4-bytes and 8-bytes types, although GCC also
+ * supports 1 and 2-bytes types. Some non-x86 architectures do not support
+ * 8-byte atomic types (or not efficiently). */
+# if defined (_MSC_VER)
+/* Some atomic operations of the Interlocked API are only
+ available for desktop apps. Thus we define the atomic types to
+ be at least 32 bits wide. */
+typedef int_least32_t atomic_flag;
+typedef int_least32_t atomic_bool;
+typedef int_least32_t atomic_char;
+typedef int_least32_t atomic_schar;
+typedef uint_least32_t atomic_uchar;
+typedef int_least32_t atomic_short;
+typedef uint_least32_t atomic_ushort;
+# else
+typedef bool atomic_flag;
+typedef bool atomic_bool;
+typedef char atomic_char;
+typedef signed char atomic_schar;
+typedef unsigned char atomic_uchar;
+typedef short atomic_short;
+typedef unsigned short atomic_ushort;
+# endif
+typedef int atomic_int;
+typedef unsigned int atomic_uint;
+typedef long atomic_long;
+typedef unsigned long atomic_ulong;
+typedef long long atomic_llong;
+typedef unsigned long long atomic_ullong;
+//typedef char16_t atomic_char16_t;
+//typedef char32_t atomic_char32_t;
+typedef wchar_t atomic_wchar_t;
+typedef int_least8_t atomic_int_least8_t;
+typedef uint_least8_t atomic_uint_least8_t;
+typedef int_least16_t atomic_int_least16_t;
+typedef uint_least16_t atomic_uint_least16_t;
+typedef int_least32_t atomic_int_least32_t;
+typedef uint_least32_t atomic_uint_least32_t;
+typedef int_least64_t atomic_int_least64_t;
+typedef uint_least64_t atomic_uint_least64_t;
+typedef int_fast8_t atomic_int_fast8_t;
+typedef uint_fast8_t atomic_uint_fast8_t;
+typedef int_fast16_t atomic_int_fast16_t;
+typedef uint_fast16_t atomic_uint_fast16_t;
+typedef int_fast32_t atomic_int_fast32_t;
+typedef uint_fast32_t atomic_uint_fast32_t;
+typedef int_fast64_t atomic_int_fast64_t;
+typedef uint_fast64_t atomic_uint_fast64_t;
+typedef intptr_t atomic_intptr_t;
+typedef uintptr_t atomic_uintptr_t;
+typedef size_t atomic_size_t;
+typedef ptrdiff_t atomic_ptrdiff_t;
+typedef intmax_t atomic_intmax_t;
+typedef uintmax_t atomic_uintmax_t;
+
+# if defined (__GCC_HAVE_SYNC_COMPARE_AND_SWAP_4) || (defined (__clang__) && (defined (__x86_64__) || defined (__i386__)))
+
+/*** Intel/GCC atomics ***/
+
+# define atomic_store(object,desired) \
+ do { \
+ *(object) = (desired); \
+ __sync_synchronize(); \
+ } while (0)
+
+# define atomic_store_explicit(object,desired,order) \
+ atomic_store(object,desired)
+
+# define atomic_load(object) \
+ (__sync_synchronize(), *(object))
+
+# define atomic_load_explicit(object,order) \
+ atomic_load(object)
+
+# define atomic_exchange(object,desired) \
+({ \
+ typeof (object) _obj = (object); \
+ typeof (*object) _old; \
+ do \
+ _old = atomic_load(_obj); \
+ while (!__sync_bool_compare_and_swap(_obj, _old, (desired))); \
+ _old; \
+})
+
+# define atomic_exchange_explicit(object,desired,order) \
+ atomic_exchange(object,desired)
+
+# define atomic_compare_exchange(object,expected,desired) \
+({ \
+ typeof (object) _exp = (expected); \
+ typeof (*object) _old = *_exp; \
+ *_exp = __sync_val_compare_and_swap((object), _old, (desired)); \
+ *_exp == _old; \
+})
+
+# define atomic_compare_exchange_strong(object,expected,desired) \
+ atomic_compare_exchange(object, expected, desired)
+
+# define atomic_compare_exchange_strong_explicit(object,expected,desired,order) \
+ atomic_compare_exchange_strong(object, expected, desired)
+
+# define atomic_compare_exchange_weak(object,expected,desired) \
+ atomic_compare_exchange(object, expected, desired)
+
+# define atomic_compare_exchange_weak_explicit(object,expected,desired,order) \
+ atomic_compare_exchange_weak(object, expected, desired)
+
+# define atomic_fetch_add(object,operand) \
+ __sync_fetch_and_add(object, operand)
+
+# define atomic_fetch_add_explicit(object,operand,order) \
+ atomic_fetch_add(object,operand)
+
+# define atomic_fetch_sub(object,operand) \
+ __sync_fetch_and_sub(object, operand)
+
+# define atomic_fetch_sub_explicit(object,operand,order) \
+ atomic_fetch_sub(object,operand)
+
+# define atomic_fetch_or(object,operand) \
+ __sync_fetch_and_or(object, operand)
+
+# define atomic_fetch_or_explicit(object,operand,order) \
+ atomic_fetch_or(object,operand)
+
+# define atomic_fetch_xor(object,operand) \
+ __sync_fetch_and_sub(object, operand)
+
+# define atomic_fetch_xor_explicit(object,operand,order) \
+ atomic_fetch_sub(object,operand)
+
+# define atomic_fetch_and(object,operand) \
+ __sync_fetch_and_and(object, operand)
+
+# define atomic_fetch_and_explicit(object,operand,order) \
+ atomic_fetch_and(object,operand)
+
+# define atomic_flag_test_and_set(object) \
+ atomic_exchange(object, true)
+
+# define atomic_flag_test_and_set_explicit(object,order) \
+ atomic_flag_test_and_set(object)
+
+# define atomic_flag_clear(object) \
+ atomic_store(object, false)
+
+# define atomic_flag_clear_explicit(object,order) \
+ atomic_flag_clear(object)
+
+# elif defined (__GNUC__)
+
+/*** No atomics ***/
+
+# define atomic_store(object,desired) \
+ do { \
+ typeof (object) _obj = (object); \
+ typeof (*object) _des = (desired); \
+ vlc_global_lock(VLC_ATOMIC_MUTEX); \
+ *_obj = _des; \
+ vlc_global_unlock(VLC_ATOMIC_MUTEX); \
+ } while (0)
+# define atomic_store_explicit(object,desired,order) \
+ atomic_store(object,desired)
+
+# define atomic_load(object) \
+({ \
+ typeof (object) _obj = (object); \
+ typeof (*object) _old; \
+ vlc_global_lock(VLC_ATOMIC_MUTEX); \
+ _old = *_obj; \
+ vlc_global_unlock(VLC_ATOMIC_MUTEX); \
+ _old; \
+})
+# define atomic_load_explicit(object,order) \
+ atomic_load(object)
+
+# define atomic_exchange(object,desired) \
+({ \
+ typeof (object) _obj = (object); \
+ typeof (*object) _des = (desired); \
+ typeof (*object) _old; \
+ vlc_global_lock(VLC_ATOMIC_MUTEX); \
+ _old = *_obj; \
+ *_obj = _des; \
+ vlc_global_unlock(VLC_ATOMIC_MUTEX); \
+ _old; \
+})
+# define atomic_exchange_explicit(object,desired,order) \
+ atomic_exchange(object,desired)
+
+# define atomic_compare_exchange_strong(object,expected,desired) \
+({ \
+ typeof (object) _obj = (object); \
+ typeof (object) _exp = (expected); \
+ typeof (*object) _des = (desired); \
+ bool ret; \
+ vlc_global_lock(VLC_ATOMIC_MUTEX); \
+ ret = *_obj == *_exp; \
+ if (ret) \
+ *_obj = _des; \
+ else \
+ *_exp = *_obj; \
+ vlc_global_unlock(VLC_ATOMIC_MUTEX); \
+ ret; \
+})
+# define atomic_compare_exchange_strong_explicit(object,expected,desired,order) \
+ atomic_compare_exchange_strong(object, expected, desired)
+# define atomic_compare_exchange_weak(object,expected,desired) \
+ atomic_compare_exchange_strong(object, expected, desired)
+# define atomic_compare_exchange_weak_explicit(object,expected,desired,order) \
+ atomic_compare_exchange_weak(object, expected, desired)
+
+# define atomic_fetch_OP(object,desired,op) \
+({ \
+ typeof (object) _obj = (object); \
+ typeof (*object) _des = (desired); \
+ typeof (*object) _old; \
+ vlc_global_lock(VLC_ATOMIC_MUTEX); \
+ _old = *_obj; \
+ *_obj = (*_obj) op (_des); \
+ vlc_global_unlock(VLC_ATOMIC_MUTEX); \
+ _old; \
+})
+
+# define atomic_fetch_add(object,operand) \
+ atomic_fetch_OP(object,operand,+)
+# define atomic_fetch_add_explicit(object,operand,order) \
+ atomic_fetch_add(object,operand)
+
+# define atomic_fetch_sub(object,operand) \
+ atomic_fetch_OP(object,operand,-)
+# define atomic_fetch_sub_explicit(object,operand,order) \
+ atomic_fetch_sub(object,operand)
+
+# define atomic_fetch_or(object,operand) \
+ atomic_fetch_OP(object,operand,|)
+# define atomic_fetch_or_explicit(object,operand,order) \
+ atomic_fetch_or(object,operand)
+
+# define atomic_fetch_xor(object,operand) \
+ atomic_fetch_OP(object,operand,^)
+# define atomic_fetch_xor_explicit(object,operand,order) \
+ atomic_fetch_sub(object,operand)
+
+# define atomic_fetch_and(object,operand) \
+ atomic_fetch_OP(object,operand,&)
+# define atomic_fetch_and_explicit(object,operand,order) \
+ atomic_fetch_and(object,operand)
+
+# define atomic_flag_test_and_set(object) \
+ atomic_exchange(object, true)
+
+# define atomic_flag_test_and_set_explicit(object,order) \
+ atomic_flag_test_and_set(object)
+
+# define atomic_flag_clear(object) \
+ atomic_store(object, false)
+
+# define atomic_flag_clear_explicit(object,order) \
+ atomic_flag_clear(object)
+
+# elif defined (_MSC_VER)
+
+# include <windows.h>
+
+/*** Use the Interlocked API. ***/
+
+/* Define macros in order to dispatch to the correct function depending on the type.
+ Several ranges are need because some operations are not implemented for all types. */
+# define atomic_type_dispatch_32_64(operation, object, ...) \
+ (sizeof(*object) == 4 ? operation((LONG *)object, __VA_ARGS__) : \
+ sizeof(*object) == 8 ? operation##64((LONGLONG *)object, __VA_ARGS__) : \
+ (abort(), 0))
+
+# define atomic_type_dispatch_16_64(operation, object, ...) \
+ (sizeof(*object) == 2 ? operation##16((short *)object, __VA_ARGS__) : \
+ atomic_type_dispatch_32_64(operation, object, __VA_ARGS__))
+
+# define atomic_type_dispatch_8_64(operation, object, ...) \
+ (sizeof(*object) == 1 ? operation##8((char *)object, __VA_ARGS__) : \
+ atomic_type_dispatch_16_64(operation, object, __VA_ARGS__))
+
+# define atomic_store(object,desired) \
+ atomic_type_dispatch_16_64(InterlockedExchange, object, desired)
+# define atomic_store_explicit(object,desired,order) \
+ atomic_store(object, desired)
+
+# define atomic_load(object) \
+ atomic_type_dispatch_16_64(InterlockedCompareExchange, object, 0, 0)
+# define atomic_load_explicit(object,order) \
+ atomic_load(object)
+
+# define atomic_exchange(object,desired) \
+ atomic_type_dispatch_16_64(InterlockedExchange, object, desired)
+# define atomic_exchange_explicit(object,desired,order) \
+ atomic_exchange(object, desired)
+
+# define atomic_compare_exchange_strong(object,expected,desired) \
+ atomic_type_dispatch_16_64(InterlockedCompareExchange, object, *expected, desired) == *expected
+# define atomic_compare_exchange_strong_explicit(object,expected,desired,order) \
+ atomic_compare_exchange_strong(object, expected, desired)
+# define atomic_compare_exchange_weak(object,expected,desired) \
+ atomic_compare_exchange_strong(object, expected, desired)
+# define atomic_compare_exchange_weak_explicit(object,expected,desired,order) \
+ atomic_compare_exchange_weak(object, expected, desired)
+
+# define atomic_fetch_add(object,operand) \
+ atomic_type_dispatch_32_64(InterlockedExchangeAdd, object, operand)
+# define atomic_fetch_add_explicit(object,operand,order) \
+ atomic_fetch_add(object, operand)
+
+# define atomic_fetch_sub(object,operand) \
+ atomic_type_dispatch_32_64(InterlockedExchangeAdd, object, -(LONGLONG)operand)
+# define atomic_fetch_sub_explicit(object,operand,order) \
+ atomic_fetch_sub(object, operand)
+
+# define atomic_fetch_or(object,operand) \
+ atomic_type_dispatch_8_64(InterlockedOr, object, operand)
+# define atomic_fetch_or_explicit(object,operand,order) \
+ atomic_fetch_or(object, operand)
+
+# define atomic_fetch_xor(object,operand) \
+ atomic_type_dispatch_8_64(InterlockedXor, object, operand)
+# define atomic_fetch_xor_explicit(object,operand,order) \
+ atomic_fetch_sub(object, operand)
+
+# define atomic_fetch_and(object,operand) \
+ atomic_type_dispatch_8_64(InterlockedAnd, object, operand)
+# define atomic_fetch_and_explicit(object,operand,order) \
+ atomic_fetch_and(object, operand)
+
+# define atomic_flag_test_and_set(object) \
+ atomic_exchange(object, true)
+
+# define atomic_flag_test_and_set_explicit(object,order) \
+ atomic_flag_test_and_set(object)
+
+# define atomic_flag_clear(object) \
+ atomic_store(object, false)
+
+# define atomic_flag_clear_explicit(object,order) \
+ atomic_flag_clear(object)
-/* All functions return the atom value _after_ the operation. */
+# else
+# error FIXME: implement atomic operations for this compiler.
+# endif
+# endif
-VLC_EXPORT(uintptr_t, vlc_atomic_get, (const vlc_atomic_t *));
-VLC_EXPORT(uintptr_t, vlc_atomic_set, (vlc_atomic_t *, uintptr_t));
-VLC_EXPORT(uintptr_t, vlc_atomic_add, (vlc_atomic_t *, uintptr_t));
+typedef atomic_uint_least32_t vlc_atomic_float;
-static inline uintptr_t vlc_atomic_sub (vlc_atomic_t *atom, uintptr_t v)
+static inline void vlc_atomic_init_float(vlc_atomic_float *var, float f)
{
- return vlc_atomic_add (atom, -v);
+ union { float f; uint32_t i; } u;
+ u.f = f;
+ atomic_init(var, u.i);
}
-static inline uintptr_t vlc_atomic_inc (vlc_atomic_t *atom)
+/** Helper to retrieve a single precision from an atom. */
+static inline float vlc_atomic_load_float(vlc_atomic_float *atom)
{
- return vlc_atomic_add (atom, 1);
+ union { float f; uint32_t i; } u;
+ u.i = atomic_load(atom);
+ return u.f;
}
-static inline uintptr_t vlc_atomic_dec (vlc_atomic_t *atom)
+/** Helper to store a single precision into an atom. */
+static inline void vlc_atomic_store_float(vlc_atomic_float *atom, float f)
{
- return vlc_atomic_sub (atom, 1);
+ union { float f; uint32_t i; } u;
+ u.f = f;
+ atomic_store(atom, u.i);
}
#endif
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