Fix shutdown A/V issue when IBC logging with the Music Store app

This app continues to run managed code on other threads after the Main thread exits and enters shutdown.
We now block IBC logging during the time that we are writing out the IBC data.

1 files changed, 15 insertions, 2 deletions

diff --git a/src/vm/ceeload.cpp b/src/vm/ceeload.cpp
index 0845d8608f..5de7114eb1 100644
--- a/src/vm/ceeload.cpp
+++ b/src/vm/ceeload.cpp
@@ -3586,8 +3586,21 @@ void Module::StartUnload()
     }
 #endif // PROFILING_SUPPORTED
 #ifdef FEATURE_PREJIT 
-    // Write out the method profile data
-    /*hr=*/WriteMethodProfileDataLogFile(true);
+    if (g_IBCLogger.InstrEnabled())
+    {
+        Thread * pThread = GetThread();
+        ThreadLocalIBCInfo* pInfo = pThread->GetIBCInfo();
+
+        // Acquire the Crst lock before creating the IBCLoggingDisabler object.
+        // Only one thread at a time can be processing an IBC logging event.
+        CrstHolder lock(g_IBCLogger.GetSync());
+        {
+            IBCLoggingDisabler disableLogging( pInfo );  // runs IBCLoggingDisabler::DisableLogging
+
+            // Write out the method profile data
+            /*hr=*/WriteMethodProfileDataLogFile(true);
+        }
+    }
 #endif // FEATURE_PREJIT
     SetBeingUnloaded();
 }