merged in recent changes

1 files changed, 16 insertions, 24 deletions

diff --git a/indra/llcommon/llthread.h b/indra/llcommon/llthread.h
index 0fb89c5613..f51d985b5f 100755
--- a/indra/llcommon/llthread.h
+++ b/indra/llcommon/llthread.h
@@ -242,49 +242,39 @@ public:
 	LLThreadSafeRefCount(const LLThreadSafeRefCount&);
 	LLThreadSafeRefCount& operator=(const LLThreadSafeRefCount& ref) 
 	{
-		if (sMutex)
-		{
-			sMutex->lock();
-		}
 		mRef = 0;
-		if (sMutex)
-		{
-			sMutex->unlock();
-		}
 		return *this;
 	}
 
-
-	
 	void ref()
 	{
-		if (sMutex) sMutex->lock();
 		mRef++; 
-		if (sMutex) sMutex->unlock();
 	} 
 
-	S32 unref()
+	void unref()
 	{
 		llassert(mRef >= 1);
-		if (sMutex) sMutex->lock();
-		S32 res = --mRef;
-		if (sMutex) sMutex->unlock();
-		if (0 == res) 
-		{
-			delete this; 
-			return 0;
+		if ((--mRef) == 0)		// See note in llapr.h on atomic decrement operator return value.  
+		{	
+			// If we hit zero, the caller should be the only smart pointer owning the object and we can delete it.
+			// It is technically possible for a vanilla pointer to mess this up, or another thread to
+			// jump in, find this object, create another smart pointer and end up dangling, but if
+			// the code is that bad and not thread-safe, it's trouble already.
+			delete this;
 		}
-		return res;
-	}	
+	}
+
 	S32 getNumRefs() const
 	{
-		return mRef;
+		const S32 currentVal = mRef.CurrentValue();
+		return currentVal;
 	}
 
 private: 
-	S32	mRef; 
+	LLAtomic32< S32	> mRef; 
 };
 
+
 /**
  * intrusive pointer support for LLThreadSafeRefCount
  * this allows you to use boost::intrusive_ptr with any LLThreadSafeRefCount-derived type
@@ -315,4 +305,6 @@ public:
 
 //============================================================================
 
+extern LL_COMMON_API void assert_main_thread();
+
 #endif // LL_LLTHREAD_H