1 files changed, 65 insertions, 0 deletions
diff --git a/indra/llcommon/llerror.cpp b/indra/llcommon/llerror.cpp
index d671decccb..b135dafb3c 100644
--- a/indra/llcommon/llerror.cpp
+++ b/indra/llcommon/llerror.cpp
@@ -1223,9 +1223,62 @@ namespace LLError
 	char** LLCallStacks::sBuffer = NULL ;
 	S32    LLCallStacks::sIndex  = 0 ;
 
+	class CallStacksLogLock
+	{
+	public:
+		CallStacksLogLock();
+		~CallStacksLogLock();
+		bool ok() const { return mOK; }
+	private:
+		bool mLocked;
+		bool mOK;
+	};
+	
+	CallStacksLogLock::CallStacksLogLock()
+		: mLocked(false), mOK(false)
+	{
+		if (!gCallStacksLogMutexp)
+		{
+			mOK = true;
+			return;
+		}
+		
+		const int MAX_RETRIES = 5;
+		for (int attempts = 0; attempts < MAX_RETRIES; ++attempts)
+		{
+			apr_status_t s = apr_thread_mutex_trylock(gCallStacksLogMutexp);
+			if (!APR_STATUS_IS_EBUSY(s))
+			{
+				mLocked = true;
+				mOK = true;
+				return;
+			}
+
+			ms_sleep(1);
+		}
+
+		// We're hosed, we can't get the mutex.  Blah.
+		std::cerr << "CallStacksLogLock::CallStacksLogLock: failed to get mutex for log"
+					<< std::endl;
+	}
+	
+	CallStacksLogLock::~CallStacksLogLock()
+	{
+		if (mLocked)
+		{
+			apr_thread_mutex_unlock(gCallStacksLogMutexp);
+		}
+	}
+
 	//static
    void LLCallStacks::push(const char* function, const int line)
    {
+	   CallStacksLogLock lock;
+       if (!lock.ok())
+       {
+           return;
+       }
+
 	   if(!sBuffer)
 	   {
 		   sBuffer = new char*[512] ;
@@ -1261,6 +1314,12 @@ namespace LLError
    //static
    void LLCallStacks::end(std::ostringstream* _out)
    {
+	   CallStacksLogLock lock;
+       if (!lock.ok())
+       {
+           return;
+       }
+
 	   if(!sBuffer)
 	   {
 		   sBuffer = new char*[512] ;
@@ -1283,6 +1342,12 @@ namespace LLError
    //static
    void LLCallStacks::print()
    {
+	   CallStacksLogLock lock;
+       if (!lock.ok())
+       {
+           return;
+       }
+
        if(sIndex > 0)
        {
            llinfos << " ************* PRINT OUT LL CALL STACKS ************* " << llendl ;