Add Interlocked.MemoryBarrierProcessWide

Contributes to https://github.com/dotnet/corefx/issues/16799

[tfs-changeset: 1652035]

3 files changed, 17 insertions, 0 deletions

diff --git a/src/Native/Runtime/MiscHelpers.cpp b/src/Native/Runtime/MiscHelpers.cpp
index ecc131bbf..0db61bcf4 100644
--- a/src/Native/Runtime/MiscHelpers.cpp
+++ b/src/Native/Runtime/MiscHelpers.cpp
@@ -62,6 +62,15 @@ EXTERN_C REDHAWK_API UInt32_BOOL __cdecl RhYield()
     return PalSwitchToThread();
 }
 
+EXTERN_C REDHAWK_API void __cdecl RhFlushProcessWriteBuffers()
+{
+    // This must be called via p/invoke -- it's a wait operation and we don't want to block thread suspension on this.
+    ASSERT_MSG(!ThreadStore::GetCurrentThread()->IsCurrentThreadInCooperativeMode(),
+        "You must p/invoke to RhFlushProcessWriteBuffers");
+
+    PalFlushProcessWriteBuffers();
+}
+
 // Return the DispatchMap pointer of a type
 COOP_PINVOKE_HELPER(DispatchMap*, RhGetDispatchMapForType, (EEType * pEEType))
 {
diff --git a/src/System.Private.CoreLib/src/System/Runtime/RuntimeImports.cs b/src/System.Private.CoreLib/src/System/Runtime/RuntimeImports.cs
index 4ec05b07b..9424e17d9 100644
--- a/src/System.Private.CoreLib/src/System/Runtime/RuntimeImports.cs
+++ b/src/System.Private.CoreLib/src/System/Runtime/RuntimeImports.cs
@@ -325,6 +325,9 @@ namespace System.Runtime
         private static extern int _RhYield();
         internal static bool RhYield() { return (_RhYield() != 0); }
 
+        [DllImport(RuntimeLibrary, EntryPoint = "RhFlushProcessWriteBuffers", CallingConvention = CallingConvention.Cdecl, ExactSpelling = true)]
+        internal static extern void RhFlushProcessWriteBuffers();
+
         // Wait for any object to be signalled, in a way that's compatible with the CLR's behavior in an STA.
         // ExactSpelling = 'true' to force MCG to resolve it to default
         [DllImport(RuntimeLibrary, ExactSpelling = true)]
diff --git a/src/System.Private.CoreLib/src/System/Threading/Interlocked.cs b/src/System.Private.CoreLib/src/System/Threading/Interlocked.cs
index 303e40249..5cce895c0 100644
--- a/src/System.Private.CoreLib/src/System/Threading/Interlocked.cs
+++ b/src/System.Private.CoreLib/src/System/Threading/Interlocked.cs
@@ -495,5 +495,10 @@ namespace System.Threading
         #endregion
 
 #endif // CORERT
+
+        public static void MemoryBarrierProcessWide()
+        {
+            RuntimeImports.RhFlushProcessWriteBuffers();
+        }
     }
 }