Add an RAII ScopedWriter, which allows one to acquire a writer lock for the duration of a scope. Simplify a lot of uses of

writer locks in Constants.cpp by using it.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@73630 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 2b466f20b4..6ac7aa3c2b 100644
--- a/include/llvm/System/RWMutex.h
+++ b/include/llvm/System/RWMutex.h
@@ -78,6 +78,20 @@ namespace llvm
       void operator=(const RWMutex &);
     /// @}
     };
+    
+    /// ScopedWriter - RAII acquisition of a writer lock
+    struct ScopedWriter {
+      RWMutex* mutex;
+      
+      explicit ScopedWriter(RWMutex* m) {
+        mutex = m;
+        mutex->writer_acquire();
+      }
+      
+      ~ScopedWriter() {
+        mutex->writer_release();
+      }
+    };
   }
 }