Implement atomic operations for MSVC using the Interlocked API.

Signed-off-by: Jean-Baptiste Kempf <jb@videolan.org>

include/vlc_atomic.h

@@ -302,6 +302,86 @@ typedef         uintmax_t atomic_uintmax_t;
 #  define atomic_flag_clear_explicit(object,order) \
     atomic_flag_clear(object)
 
+# elif defined (_MSC_VER)
+
+/*** 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(object, __VA_ARGS__) : \
+     sizeof(*object) == 8 ? operation##64(object, __VA_ARGS__) : \
+     (abort(), 0))
+
+#  define atomic_type_dispatch_16_64(operation, object, ...) \
+    (sizeof(*object) == 2 ? operation##16(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(object, __VA_ARGS__) : \
+     atomic_type_dispatch_16_64(operation, object, __VA_ARGS__))
+
+#  define atomic_store(object,desired) \
+    atomic_type_dispatch_8_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_8_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, -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)
+
 # else
 #  error FIXME: implement atomic operations for this compiler.
 # endif