a debug tool to detect LLPointer issues for SH-694: check if there are any other LLPointer issues in the mesh model uploading flow and fix them if exist.

This debug tool is off by default. To turn it on, set LL_REF_COUNT_DEBUG to be 1 in the header file "llcommon/llrefcount.h".

indra/llcommon/llrefcount.cpp

@@ -29,9 +29,25 @@
 
 #include "llerror.h"
 
+#if LL_REF_COUNT_DEBUG
+#include "llthread.h"
+#include "llapr.h"
+#endif
+
 LLRefCount::LLRefCount(const LLRefCount& other)
 :	mRef(0)
 {
+#if LL_REF_COUNT_DEBUG
+	if(gAPRPoolp)
+	{
+		mMutexp = new LLMutex(gAPRPoolp) ;
+	}
+	else
+	{
+		mMutexp = NULL ;
+	}
+	mCrashAtUnlock = FALSE ;
+#endif
 }
 
 LLRefCount& LLRefCount::operator=(const LLRefCount&)
@@ -43,6 +59,17 @@ LLRefCount& LLRefCount::operator=(const LLRefCount&)
 LLRefCount::LLRefCount() :
 	mRef(0)
 {
+#if LL_REF_COUNT_DEBUG
+	if(gAPRPoolp)
+	{
+		mMutexp = new LLMutex(gAPRPoolp) ;
+	}
+	else
+	{
+		mMutexp = NULL ;
+	}
+	mCrashAtUnlock = FALSE ;
+#endif
 }
 
 LLRefCount::~LLRefCount()
@@ -51,4 +78,87 @@ LLRefCount::~LLRefCount()
 	{
 		llerrs << "deleting non-zero reference" << llendl;
 	}
+
+#if LL_REF_COUNT_DEBUG
+	if(gAPRPoolp)
+	{
+		delete mMutexp ;
+	}
+#endif
 }
+
+#if LL_REF_COUNT_DEBUG
+void LLRefCount::ref() const
+{ 
+	if(mMutexp)
+	{
+		if(mMutexp->isLocked()) 
+		{
+			mCrashAtUnlock = TRUE ;
+			llerrs << "the mutex is locked by the thread: " << mLockedThreadID 
+				<< " Current thread: " << LLThread::currentID() << llendl ;
+		}
+
+		mMutexp->lock() ;
+		mLockedThreadID = LLThread::currentID() ;
+
+		mRef++; 
+
+		if(mCrashAtUnlock)
+		{
+			while(1); //crash here.
+		}
+		mMutexp->unlock() ;
+	}
+	else
+	{
+		mRef++; 
+	}
+} 
+
+S32 LLRefCount::unref() const
+{
+	if(mMutexp)
+	{
+		if(mMutexp->isLocked()) 
+		{
+			mCrashAtUnlock = TRUE ;
+			llerrs << "the mutex is locked by the thread: " << mLockedThreadID 
+				<< " Current thread: " << LLThread::currentID() << llendl ;
+		}
+
+		mMutexp->lock() ;
+		mLockedThreadID = LLThread::currentID() ;
+		
+		llassert(mRef >= 1);
+		if (0 == --mRef) 
+		{
+			if(mCrashAtUnlock)
+			{
+				while(1); //crash here.
+			}
+			mMutexp->unlock() ;
+
+			delete this; 
+			return 0;
+		}
+
+		if(mCrashAtUnlock)
+		{
+			while(1); //crash here.
+		}
+		mMutexp->unlock() ;
+		return mRef;
+	}
+	else
+	{
+		llassert(mRef >= 1);
+		if (0 == --mRef) 
+		{
+			delete this; 
+			return 0;
+		}
+		return mRef;
+	}
+}	
+#endif

indra/llcommon/llrefcount.h

@@ -28,6 +28,11 @@
 
 #include <boost/noncopyable.hpp>
 
+#define LL_REF_COUNT_DEBUG 0
+#if LL_REF_COUNT_DEBUG
+class LLMutex ;
+#endif
+
 //----------------------------------------------------------------------------
 // RefCount objects should generally only be accessed by way of LLPointer<>'s
 // see llthread.h for LLThreadSafeRefCount
@@ -43,12 +48,16 @@ protected:
 public:
 	LLRefCount();
 
-	void ref() const
+#if LL_REF_COUNT_DEBUG
+	void ref() const ;
+	S32 unref() const ;
+#else
+	inline void LLRefCount::ref() const
 	{ 
 		mRef++; 
 	} 
 
-	S32 unref() const
+	inline S32 LLRefCount::unref() const
 	{
 		llassert(mRef >= 1);
 		if (0 == --mRef) 
@@ -58,6 +67,7 @@ public:
 		}
 		return mRef;
 	}	
+#endif
 
 	//NOTE: when passing around a const LLRefCount object, this can return different results
 	// at different types, since mRef is mutable
@@ -68,6 +78,12 @@ public:
 
 private: 
 	mutable S32	mRef; 
+
+#if LL_REF_COUNT_DEBUG
+	LLMutex*  mMutexp ;
+	mutable U32  mLockedThreadID ;
+	mutable BOOL mCrashAtUnlock ; 
+#endif
 };
 
 #endif