1 files changed, 51 insertions, 24 deletions

diff --git a/indra/llcommon/llthread.h b/indra/llcommon/llthread.h
index b52e70ab2e..f51d985b5f 100644..100755
--- a/indra/llcommon/llthread.h
+++ b/indra/llcommon/llthread.h
@@ -30,6 +30,7 @@
 #include "llapp.h"
 #include "llapr.h"
 #include "apr_thread_cond.h"
+#include "boost/intrusive_ptr.hpp"
 
 class LLThread;
 class LLMutex;
@@ -88,6 +89,11 @@ public:
 
 	U32 getID() const { return mID; }
 
+	// Called by threads *not* created via LLThread to register some
+	// internal state used by LLMutex.  You must call this once early
+	// in the running thread to prevent collisions with the main thread.
+	static void registerThreadID();
+	
 private:
 	BOOL				mPaused;
 	
@@ -97,6 +103,7 @@ private:
 protected:
 	std::string			mName;
 	LLCondition*		mRunCondition;
+	LLMutex*			mDataLock;
 
 	apr_thread_t		*mAPRThreadp;
 	apr_pool_t			*mAPRPoolp;
@@ -122,15 +129,15 @@ protected:
 	inline void unlockData();
 	
 	// This is the predicate that decides whether the thread should sleep.  
-	// It should only be called with mRunCondition locked, since the virtual runCondition() function may need to access
+	// It should only be called with mDataLock locked, since the virtual runCondition() function may need to access
 	// data structures that are thread-unsafe.
 	bool shouldSleep(void) { return (mStatus == RUNNING) && (isPaused() || (!runCondition())); }
 
 	// To avoid spurious signals (and the associated context switches) when the condition may or may not have changed, you can do the following:
-	// mRunCondition->lock();
+	// mDataLock->lock();
 	// if(!shouldSleep())
 	//     mRunCondition->signal();
-	// mRunCondition->unlock();
+	// mDataLock->unlock();
 };
 
 //============================================================================
@@ -205,12 +212,12 @@ private:
 
 void LLThread::lockData()
 {
-	mRunCondition->lock();
+	mDataLock->lock();
 }
 
 void LLThread::unlockData()
 {
-	mRunCondition->unlock();
+	mDataLock->unlock();
 }
 
 
@@ -227,45 +234,63 @@ public:
 private:
 	static LLMutex* sMutex;
 
-private:
-	LLThreadSafeRefCount(const LLThreadSafeRefCount&); // not implemented
-	LLThreadSafeRefCount&operator=(const LLThreadSafeRefCount&); // not implemented
-
 protected:
 	virtual ~LLThreadSafeRefCount(); // use unref()
 	
 public:
 	LLThreadSafeRefCount();
-	
+	LLThreadSafeRefCount(const LLThreadSafeRefCount&);
+	LLThreadSafeRefCount& operator=(const LLThreadSafeRefCount& ref) 
+	{
+		mRef = 0;
+		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
+ */
+namespace boost
+{
+	inline void intrusive_ptr_add_ref(LLThreadSafeRefCount* p) 
+	{
+		p->ref();
+	}
+
+	inline void intrusive_ptr_release(LLThreadSafeRefCount* p) 
+	{
+		p->unref(); 
+	}
+};
 //============================================================================
 
 // Simple responder for self destructing callbacks
@@ -280,4 +305,6 @@ public:
 
 //============================================================================
 
+extern LL_COMMON_API void assert_main_thread();
+
 #endif // LL_LLTHREAD_H