X-Git-Url: http://demsky.eecs.uci.edu/git/?a=blobdiff_plain;f=include%2Fllvm%2FSystem%2FMutex.h;h=d2c457dbc91c6d14203295740c6442196d5433a6;hb=ed1c0ffe0b2287deaee7cba7506c93aa34c6d4b7;hp=0003ef881c85d13ddfeafaea4d1f2fe1aeb1617f;hpb=1b19a50cdb292e144ea27bef1cd135efaa6548df;p=oota-llvm.git

diff --git a/include/llvm/System/Mutex.h b/include/llvm/System/Mutex.h
index 0003ef881c8..d2c457dbc91 100644
--- 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
 {
@@ -85,18 +86,32 @@ 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())
           return MutexImpl::acquire();
+        
+        // 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())
           return MutexImpl::release();
+        
+        // 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;
       }