Merge pull request #4594 from lambdageek/bug-53890

[mono.git] / mono / utils / mono-membar.h

diff --git a/mono/utils/mono-membar.h b/mono/utils/mono-membar.h
index 5946dc18dc0334b7d6b1d0f8e742c4d15aa61671..3f937b3b43164c6f8a97015bcff49fc6632324b3 100644 (file)
--- a/mono/utils/mono-membar.h
+++ b/mono/utils/mono-membar.h
@@ -1,5 +1,6 @@
-/*
- * mono-membar.h: Memory barrier inline functions
+/**
+ * \file
+ * Memory barrier inline functions
  *
  * Author:
  *     Mark Probst (mark.probst@gmail.com)
@@ -15,21 +16,35 @@
 #include <glib.h>
 
 #ifdef _MSC_VER
+#ifndef WIN32_LEAN_AND_MEAN
+#define WIN32_LEAN_AND_MEAN
+#endif
+#include <windows.h>
 #include <intrin.h>
 
 static inline void mono_memory_barrier (void)
 {
+       /* NOTE: _ReadWriteBarrier and friends only prevent the
+          compiler from reordering loads and stores. To prevent
+          the CPU from doing the same, we have to use the
+          MemoryBarrier macro which expands to e.g. a serializing
+          XCHG instruction on x86. Also note that the MemoryBarrier
+          macro does *not* imply _ReadWriteBarrier, so that call
+          cannot be eliminated. */
        _ReadWriteBarrier ();
+       MemoryBarrier ();
 }
 
 static inline void mono_memory_read_barrier (void)
 {
        _ReadBarrier ();
+       MemoryBarrier ();
 }
 
 static inline void mono_memory_write_barrier (void)
 {
        _WriteBarrier ();
+       MemoryBarrier ();
 }
 #elif defined(USE_GCC_ATOMIC_OPS)
 static inline void mono_memory_barrier (void)
@@ -46,78 +61,8 @@ static inline void mono_memory_write_barrier (void)
 {
        mono_memory_barrier ();
 }
-#elif defined(sparc) || defined(__sparc__)
-static inline void mono_memory_barrier (void)
-{
-       __asm__ __volatile__ ("membar   #LoadLoad | #LoadStore | #StoreStore | #StoreLoad" : : : "memory");
-}
-
-static inline void mono_memory_read_barrier (void)
-{
-       __asm__ __volatile__ ("membar   #LoadLoad" : : : "memory");
-}
-
-static inline void mono_memory_write_barrier (void)
-{
-       __asm__ __volatile__ ("membar   #StoreStore" : : : "memory");
-}
-#elif defined(__s390__)
-static inline void mono_memory_barrier (void)
-{
-       __asm__ __volatile__ ("bcr 15,0" : : : "memory");
-}
-
-static inline void mono_memory_read_barrier (void)
-{
-       mono_memory_barrier ();
-}
-
-static inline void mono_memory_write_barrier (void)
-{
-       mono_memory_barrier ();
-}
-#elif defined(__ia64__)
-static inline void mono_memory_barrier (void)
-{
-       __asm__ __volatile__ ("mf" : : : "memory");
-}
-
-static inline void mono_memory_read_barrier (void)
-{
-       mono_memory_barrier ();
-}
-
-static inline void mono_memory_write_barrier (void)
-{
-       mono_memory_barrier ();
-}
-#elif defined(__mips__)
-static inline void mono_memory_barrier (void)
-{
-        __asm__ __volatile__ ("" : : : "memory");
-}
-
-static inline void mono_memory_read_barrier (void)
-{
-        mono_memory_barrier ();
-}
-
-static inline void mono_memory_write_barrier (void)
-{
-        mono_memory_barrier ();
-}
-#elif defined(MONO_CROSS_COMPILE)
-static inline void mono_memory_barrier (void)
-{
-}
-
-static inline void mono_memory_read_barrier (void)
-{
-}
-
-static inline void mono_memory_write_barrier (void)
-{
-}
+#else
+#error "Don't know how to do memory barriers!"
 #endif
 
 #endif /* _MONO_UTILS_MONO_MEMBAR_H_ */