Protect the GC table in Function.cpp

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@73647 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 14 insertions, 0 deletions

diff --git a/include/llvm/System/RWMutex.h b/include/llvm/System/RWMutex.h
index 6ac7aa3..8967e9e 100644
--- a/include/llvm/System/RWMutex.h
+++ b/include/llvm/System/RWMutex.h
@@ -79,6 +79,20 @@ namespace llvm
     /// @}
     };
     
+    /// ScopedReader - RAII acquisition of a writer lock
+    struct ScopedReader {
+      RWMutex* mutex;
+      
+      explicit ScopedReader(RWMutex* m) {
+        mutex = m;
+        mutex->reader_acquire();
+      }
+      
+      ~ScopedReader() {
+        mutex->reader_release();
+      }
+    };
+    
     /// ScopedWriter - RAII acquisition of a writer lock
     struct ScopedWriter {
       RWMutex* mutex;