atomic: Add support for WIN32 atomic operations

Windows provides atomic operation APIs so use it

src/cairo-atomic-private.h

@@ -279,6 +279,67 @@ typedef int64_t cairo_atomic_intptr_t;
 
 #endif
 
+#if !defined(HAS_ATOMIC_OPS) && defined(_WIN32)
+#include <windows.h>
+
+#define HAS_ATOMIC_OPS 1
+
+typedef int32_t cairo_atomic_int_t;
+
+#if SIZEOF_VOID_P==SIZEOF_INT
+typedef unsigned int cairo_atomic_intptr_t;
+#elif SIZEOF_VOID_P==SIZEOF_LONG
+typedef unsigned long cairo_atomic_intptr_t;
+#elif SIZEOF_VOID_P==SIZEOF_LONG_LONG
+typedef unsigned long long cairo_atomic_intptr_t;
+#else
+#error No matching integer pointer type
+#endif
+
+static cairo_always_inline cairo_atomic_int_t
+_cairo_atomic_int_get (cairo_atomic_int_t *x)
+{
+    MemoryBarrier ();
+    return *x;
+}
+
+# define _cairo_atomic_int_get_relaxed(x) *(x)
+# define _cairo_atomic_int_set_relaxed(x, val) *(x) = (val)
+
+# define _cairo_atomic_int_inc(x) ((void) InterlockedIncrement (x))
+# define _cairo_atomic_int_dec(x) ((void) InterlockedDecrement (x))
+# define _cairo_atomic_int_dec_and_test(x) (InterlockedDecrement (x) == 0)
+
+static cairo_always_inline cairo_bool_t
+_cairo_atomic_int_cmpxchg (cairo_atomic_int_t *x,
+                           cairo_atomic_int_t oldv,
+                           cairo_atomic_int_t newv)
+{
+    return InterlockedCompareExchange (x, newv, oldv) == oldv;
+}
+
+static cairo_always_inline void *
+_cairo_atomic_ptr_get (void **x)
+{
+    MemoryBarrier ();
+    return *x;
+}
+
+static cairo_always_inline cairo_bool_t
+_cairo_atomic_ptr_cmpxchg (void **x, void *oldv, void *newv)
+{
+    return InterlockedCompareExchangePointer (x, newv, oldv) == oldv;
+}
+
+static cairo_always_inline void *
+_cairo_atomic_ptr_cmpxchg_return_old (void **x, void *oldv, void *newv)
+{
+    return InterlockedCompareExchangePointer (x, newv, oldv);
+}
+
+#endif /* !defined(HAS_ATOMIC_OPS) && defined(_WIN32) */
+
+
 #ifndef HAS_ATOMIC_OPS
 
 #if SIZEOF_VOID_P==SIZEOF_INT