add simplistic stdatomic.h compatible with MSVC

Only the functions needed with the current code are defined.

The header will not work with other compilers. It will need to be updated for
each compiler that doesn't have stdatomic.h.

1 files changed, 70 insertions, 0 deletions

diff --git a/include/compat/stdatomic.h b/include/compat/stdatomic.h
new file mode 100644
index 0000000..28fe40c
--- /dev/null
+++ b/include/compat/stdatomic.h
@@ -0,0 +1,70 @@
+/*
+* Copyright © 2018, VideoLAN and dav1d authors
+* All rights reserved.
+*
+* Redistribution and use in source and binary forms, with or without
+* modification, are permitted provided that the following conditions are met:
+*
+* 1. Redistributions of source code must retain the above copyright notice, this
+*    list of conditions and the following disclaimer.
+*
+* 2. Redistributions in binary form must reproduce the above copyright notice,
+*    this list of conditions and the following disclaimer in the documentation
+*    and/or other materials provided with the distribution.
+*
+* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
+* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
+* WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+* DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR
+* ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
+* (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
+* LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
+* ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
+* SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+*/
+

+#ifndef MSCVER_STDATOMIC_H_

+#define MSCVER_STDATOMIC_H_

+

+#if !defined(__cplusplus) && defined(_MSC_VER)
+
+#pragma warning(push)
+#pragma warning(disable:4067)    /* newline for __has_include_next */
+
+#if defined(__clang__) && __has_include_next(<stdatomic.h>)
+   /* use the clang stdatomic.h with clang-cl*/
+#  include_next <stdatomic.h>
+#else /* ! stdatomic.h */
+
+#include <windows.h>

+

+#include "common/attributes.h"

+

+typedef volatile LONG  __declspec(align(32)) atomic_int;

+typedef volatile ULONG __declspec(align(32)) atomic_uint;

+

+typedef enum {

+    memory_order_relaxed,

+    memory_order_acquire

+} msvc_atomic_memory_order;

+

+#define atomic_init(p_a, v)           do { *(p_a) = (v); } while(0)

+#define atomic_store(p_a, v)          InterlockedExchange((LONG*)p_a, v)

+#define atomic_load(p_a)              InterlockedCompareExchange((LONG*)p_a, 0, 0)

+#define atomic_load_explicit(p_a, mo) atomic_load(p_a)

+

+/*

+ * TODO use a special call to increment/decrement

+ * using InterlockedIncrement/InterlockedDecrement

+ */

+#define atomic_fetch_add(p_a, inc)    InterlockedExchangeAdd(p_a, inc)

+#define atomic_fetch_sub(p_a, dec)    InterlockedExchangeAdd(p_a, -(dec))

+

+#endif /* ! stdatomic.h */

+

+#pragma warning(pop)

+

+#endif /* !defined(__cplusplus) && defined(_MSC_VER) */

+

+#endif /* MSCVER_STDATOMIC_H_ */