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[oota-llvm.git] / include / llvm / System / Mutex.h

diff --git a/include/llvm/System/Mutex.h b/include/llvm/System/Mutex.h
index d8a18865f68054529fa05b80ddd9b8ea9f41f618..71d10067c303442ffda43d857709106c9fb88f77 100644 (file)
--- a/include/llvm/System/Mutex.h
+++ b/include/llvm/System/Mutex.h
@@ -15,6 +15,7 @@
 #define LLVM_SYSTEM_MUTEX_H
 
 #include "llvm/System/Threading.h"
+#include <cassert>
 
 namespace llvm
 {
@@ -68,9 +69,7 @@ namespace llvm
     /// @name Platform Dependent Data
     /// @{
     private:
-#ifdef ENABLE_THREADS
       void* data_; ///< We don't know what the data will be
-#endif
 
     /// @}
     /// @name Do Not Implement
@@ -87,25 +86,43 @@ namespace llvm
     /// running in multithreaded mode.
     template<bool mt_only>
     class SmartMutex : public MutexImpl {
+      unsigned acquired;
+      bool recursive;
     public:
-      explicit SmartMutex(bool recursive = true) : MutexImpl(recursive) { }
+      explicit SmartMutex(bool rec = true) :
+        MutexImpl(rec), acquired(0), recursive(rec) { }
       
       bool acquire() {
-        if (!mt_only && llvm_is_multithreaded())
+        if (!mt_only || llvm_is_multithreaded()) {
           return MutexImpl::acquire();
-        return true;
+        } else {
+          // Single-threaded debugging code.  This would be racy in
+          // multithreaded mode, but provides not sanity checks in single
+          // threaded mode.
+          assert((recursive || acquired == 0) && "Lock already acquired!!");
+          ++acquired;
+          return true;
+        }
       }
 
       bool release() {
-        if (!mt_only || llvm_is_multithreaded())
+        if (!mt_only || llvm_is_multithreaded()) {
           return MutexImpl::release();
-        return true;
+        } else {
+          // Single-threaded debugging code.  This would be racy in
+          // multithreaded mode, but provides not sanity checks in single
+          // threaded mode.
+          assert(((recursive && acquired) || (acquired == 1)) &&
+                 "Lock not acquired before release!");
+          --acquired;
+          return true;
+        }
       }
 
       bool tryacquire() {
         if (!mt_only || llvm_is_multithreaded())
           return MutexImpl::tryacquire();
-        return true;
+        else return true;
       }
       
       private:
@@ -115,6 +132,22 @@ namespace llvm
     
     /// Mutex - A standard, always enforced mutex.
     typedef SmartMutex<false> Mutex;
+    
+    template<bool mt_only>
+    class SmartScopedLock  {
+      SmartMutex<mt_only>& mtx;
+      
+    public:
+      SmartScopedLock(SmartMutex<mt_only>& m) : mtx(m) {
+        mtx.acquire();
+      }
+      
+      ~SmartScopedLock() {
+        mtx.release();
+      }
+    };
+    
+    typedef SmartScopedLock<false> ScopedLock;
   }
 }