*****************************************************************************
* 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.
*/
+# if !defined (__cplusplus) && (__STDC_VERSION__ >= 201112L) \
+ && !defined (__STDC_NO_ATOMICS__)
+
+/*** Native C11 atomics ***/
+# include <stdatomic.h>
+
+# elif defined (__GCC_HAVE_SYNC_COMPARE_AND_SWAP_4)
+
+/*** Intel/GCC atomics ***/
+
+# 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). So lets stick to (u)intptr_t. */
+typedef intptr_t atomic_flag;
+typedef intptr_t atomic_bool;
+typedef intptr_t atomic_char;
+typedef intptr_t atomic_schar;
+typedef uintptr_t atomic_uchar;
+typedef intptr_t atomic_short;
+typedef uintptr_t atomic_ushort;
+typedef intptr_t atomic_int;
+typedef uintptr_t atomic_uint;
+typedef intptr_t atomic_long;
+typedef uintptr_t atomic_ulong;
+//atomic_llong
+//atomic_ullong
+typedef uintptr_t atomic_char16_t;
+typedef uintptr_t atomic_char32_t;
+typedef uintptr_t atomic_wchar_t;
+typedef intptr_t atomic_int_least8_t;
+typedef uintptr_t atomic_uint_least8_t;
+typedef intptr_t atomic_int_least16_t;
+typedef uintptr_t atomic_uint_least16_t;
+typedef intptr_t atomic_int_least32_t;
+typedef uintptr_t atomic_uint_least32_t;
+//atomic_int_least64_t
+//atomic_uint_least64_t
+typedef intptr_t atomic_int_fast8_t;
+typedef uintptr_t atomic_uint_fast8_t;
+typedef intptr_t atomic_int_fast16_t;
+typedef uintptr_t atomic_uint_fast16_t;
+typedef intptr_t atomic_int_fast32_t;
+typedef uintptr_t atomic_uint_fast32_t;
+//atomic_int_fast64_t
+//atomic_uint_fast64_t
+typedef intptr_t atomic_intptr_t;
+typedef uintptr_t atomic_uintptr_t;
+typedef uintptr_t atomic_size_t;
+typedef intptr_t atomic_ptrdiff_t;
+//atomic_intmax_t
+//atomic_uintmax_t
+
+# 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)
+
+static inline
+intptr_t vlc_atomic_exchange(volatile void *object, intptr_t desired)
+{
+ volatile intptr_t *ptr = (volatile intptr_t *)object;
+ intptr_t old;
+ /* NOTE: while __sync_lock_test_and_set() is an atomic exchange, its memory
+ * order is too weak (acquire instead of sequentially consistent).
+ * Because of that, for lack of both C11 _Generic() and GNU C compound
+ * statements, atomic exchange needs a helper function.
+ * Thus all atomic types must have the same size. */
+ do
+ old = atomic_load(ptr);
+ while (!__sync_bool_compare_and_swap(ptr, old, desired));
+
+ return old;
+}
+
+# define atomic_exchange(object,desired) \
+ vlc_atomic_exchange(object,desired)
+
+# define atomic_exchange_explicit(object,desired,order) \
+ atomic_exchange(object,desired)
+
+static inline
+bool vlc_atomic_compare_exchange(volatile void *object, void *expected,
+ intptr_t desired)
+{
+ volatile intptr_t *ptr = (volatile intptr_t *)object;
+ intptr_t old = *(intptr_t *)expected;
+ intptr_t val = __sync_val_compare_and_swap(ptr, old, desired);
+ if (old != val)
+ {
+ *(intptr_t *)expected = val;
+ return false;
+ }
+ return true;
+}
+
+# define atomic_compare_exchange_strong(object,expected,desired) \
+ vlc_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) \
+ vlc_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)
+
+# else
+
+/*** No atomics ***/
+
+# 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
+
+typedef uintptr_t atomic_generic_t;
+typedef atomic_generic_t atomic_flag;
+typedef atomic_generic_t atomic_bool;
+//typedef atomic_generic_t atomic_char;
+//typedef atomic_generic_t atomic_schar;
+typedef atomic_generic_t atomic_uchar;
+//typedef atomic_generic_t atomic_short;
+typedef atomic_generic_t atomic_ushort;
+//typedef atomic_generic_t atomic_int;
+typedef atomic_generic_t atomic_uint;
+//typedef atomic_generic_t atomic_long;
+typedef atomic_generic_t atomic_ulong;
+//typedef atomic_generic_t atomic_llong;
+//typedef atomic_generic_t atomic_ullong;
+//typedef atomic_generic_t atomic_char16_t;
+//typedef atomic_generic_t atomic_char32_t;
+//typedef atomic_generic_t atomic_wchar_t;
+//typedef atomic_generic_t atomic_int_least8_t;
+typedef atomic_generic_t atomic_uint_least8_t;
+//typedef atomic_generic_t atomic_int_least16_t;
+typedef atomic_generic_t atomic_uint_least16_t;
+//typedef atomic_generic_t atomic_int_least32_t;
+typedef atomic_generic_t atomic_uint_least32_t;
+//typedef atomic_generic_t atomic_int_least64_t;
+//typedef atomic_generic_t atomic_uint_least64_t;
+//typedef atomic_generic_t atomic_int_fast8_t;
+typedef atomic_generic_t atomic_uint_fast8_t;
+//typedef atomic_generic_t atomic_int_fast16_t;
+typedef atomic_generic_t atomic_uint_fast16_t;
+//typedef atomic_generic_t atomic_int_fast32_t;
+typedef atomic_generic_t atomic_uint_fast32_t;
+//typedef atomic_generic_t atomic_int_fast64_t
+//typedef atomic_generic_t atomic_uint_fast64_t;
+//typedef atomic_generic_t atomic_intptr_t;
+typedef atomic_generic_t atomic_uintptr_t;
+typedef atomic_generic_t atomic_size_t;
+//typedef atomic_generic_t atomic_ptrdiff_t;
+//typedef atomic_generic_t atomic_intmax_t;
+//typedef atomic_generic_t atomic_uintmax_t;
+
+#define atomic_store(object,desired) \
+ do { \
+ vlc_global_lock(VLC_ATOMIC_MUTEX); \
+ *(object) = (desired); \
+ vlc_global_unlock(VLC_ATOMIC_MUTEX); \
+ } while (0)
+
+# define atomic_store_explicit(object,desired,order) \
+ atomic_store(object,desired)
+
+static inline uintptr_t atomic_load(atomic_generic_t *object)
+{
+ uintptr_t value;
+
+ vlc_global_lock(VLC_ATOMIC_MUTEX);
+ value = *object;
+ vlc_global_unlock(VLC_ATOMIC_MUTEX);
+ return value;
+}
+# define atomic_load_explicit(object,order) \
+ atomic_load(object)
+
+static inline
+uintptr_t atomic_exchange(atomic_generic_t *object, uintptr_t desired)
+{
+ uintptr_t value;
+
+ vlc_global_lock(VLC_ATOMIC_MUTEX);
+ value = *object;
+ *object = desired;
+ vlc_global_unlock(VLC_ATOMIC_MUTEX);
+ return value;
+}
+# define atomic_exchange_explicit(object,desired,order) \
+ atomic_exchange(object,desired)
+
+static inline
+bool vlc_atomic_compare_exchange(atomic_generic_t *object,
+ uintptr_t *expected, uintptr_t desired)
+{
+ bool ret;
+
+ vlc_global_lock(VLC_ATOMIC_MUTEX);
+ ret = *object == *expected;
+ if (ret)
+ *object = desired;
+ else
+ *expected = *object;
+ vlc_global_unlock(VLC_ATOMIC_MUTEX);
+ return ret;
+}
+# define atomic_compare_exchange_strong(object,expected,desired) \
+ vlc_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) \
+ vlc_atomic_compare_exchange(object, expected, desired)
+# define atomic_compare_exchange_weak_explicit(object,expected,desired,order) \
+ atomic_compare_exchange_weak(object, expected, desired)
+
+static inline
+uintmax_t atomic_fetch_add(atomic_generic_t *object, uintptr_t operand)
+{
+ uintptr_t value;
+
+ vlc_global_lock(VLC_ATOMIC_MUTEX);
+ value = *object;
+ *object += operand;
+ vlc_global_unlock(VLC_ATOMIC_MUTEX);
+ return value;
+}
+# define atomic_fetch_add_explicit(object,operand,order) \
+ atomic_fetch_add(object,operand)
+
+static inline
+uintptr_t atomic_fetch_sub(atomic_generic_t *object, uintptr_t operand)
+{
+ uintptr_t value;
+
+ vlc_global_lock(VLC_ATOMIC_MUTEX);
+ value = *object;
+ *object -= operand;
+ vlc_global_unlock(VLC_ATOMIC_MUTEX);
+ return value;
+}
+# define atomic_fetch_sub_explicit(object,operand,order) \
+ atomic_fetch_sub(object,operand)
+
+static inline
+uintptr_t atomic_fetch_or(atomic_generic_t *object, uintptr_t operand)
+{
+ uintptr_t value;
+
+ vlc_global_lock(VLC_ATOMIC_MUTEX);
+ value = *object;
+ *object |= operand;
+ vlc_global_unlock(VLC_ATOMIC_MUTEX);
+ return value;
+}
+# define atomic_fetch_or_explicit(object,operand,order) \
+ atomic_fetch_or(object,operand)
+
+static inline
+uintptr_t atomic_fetch_xor(atomic_generic_t *object, uintptr_t operand)
+{
+ uintptr_t value;
+
+ vlc_global_lock(VLC_ATOMIC_MUTEX);
+ value = *object;
+ *object ^= operand;
+ vlc_global_unlock(VLC_ATOMIC_MUTEX);
+ return value;
+}
+# define atomic_fetch_xor_explicit(object,operand,order) \
+ atomic_fetch_sub(object,operand)
+
+static inline
+uintptr_t atomic_fetch_and(atomic_generic_t *object, uintptr_t operand)
+{
+ uintptr_t value;
+
+ vlc_global_lock(VLC_ATOMIC_MUTEX);
+ value = *object;
+ *object &= operand;
+ vlc_global_unlock(VLC_ATOMIC_MUTEX);
+ return value;
+}
+# 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)
+
+# endif
+
/**
* Memory storage space for an atom. Never access it directly.
*/
typedef union
{
- uintptr_t u;
- intptr_t s;
+ atomic_uintptr_t u;
} vlc_atomic_t;
+/** Static initializer for \ref vlc_atomic_t */
+# define VLC_ATOMIC_INIT(val) { (val) }
+
/* All functions return the atom value _after_ the operation. */
+static inline uintptr_t vlc_atomic_get(vlc_atomic_t *atom)
+{
+ return atomic_load(&atom->u);
+}
+
+static inline uintptr_t vlc_atomic_set(vlc_atomic_t *atom, uintptr_t v)
+{
+ atomic_store(&atom->u, v);
+ return v;
+}
-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));
+static inline uintptr_t vlc_atomic_add(vlc_atomic_t *atom, uintptr_t v)
+{
+ return atomic_fetch_add(&atom->u, v) + v;
+}
static inline uintptr_t vlc_atomic_sub (vlc_atomic_t *atom, uintptr_t v)
{
- return vlc_atomic_add (atom, -v);
+ return atomic_fetch_sub (&atom->u, v) - v;
}
static inline uintptr_t vlc_atomic_inc (vlc_atomic_t *atom)
return vlc_atomic_sub (atom, 1);
}
+static inline uintptr_t vlc_atomic_swap(vlc_atomic_t *atom, uintptr_t v)
+{
+ return atomic_exchange(&atom->u, v);
+}
+
+static inline uintptr_t vlc_atomic_compare_swap(vlc_atomic_t *atom,
+ uintptr_t u, uintptr_t v)
+{
+ atomic_compare_exchange_strong(&atom->u, &u, v);
+ return u;
+}
+
+/** Helper to retrieve a single precision from an atom. */
+static inline float vlc_atomic_getf(vlc_atomic_t *atom)
+{
+ union { float f; uintptr_t i; } u;
+ u.i = vlc_atomic_get(atom);
+ return u.f;
+}
+
+/** Helper to store a single precision into an atom. */
+static inline float vlc_atomic_setf(vlc_atomic_t *atom, float f)
+{
+ union { float f; uintptr_t i; } u;
+ u.f = f;
+ vlc_atomic_set(atom, u.i);
+ return f;
+}
+
#endif
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