SL-16421: Destroy the "General" ThreadPool as soon as cleanup starts.

Introduce LLAppViewer::onCleanup(), a method that accepts a nullary callable
to execute once viewer shutdown begins. Fire the collected callables in
LLAppViewer::cleanup().

In llstartup.cpp, instead of declaring a static unique_ptr and relying on
static object destruction to clean up the "General" ThreadPool, bind the
pointer to the new ThreadPool into an onCleanup() lambda that will delete it
when called. ~ThreadPool() takes care of orderly shutdown.

1 files changed, 5 insertions, 0 deletions

diff --git a/indra/newview/llappviewer.cpp b/indra/newview/llappviewer.cpp
index 529db397b2..a5d32ba243 100644
--- a/indra/newview/llappviewer.cpp
+++ b/indra/newview/llappviewer.cpp
@@ -1729,6 +1729,11 @@ void LLAppViewer::flushVFSIO()
 
 bool LLAppViewer::cleanup()
 {
+	// Since we don't know what functions are going to be queued by
+	// onCleanup(), we have to assume they might rely on some of the things
+	// we're about to destroy below. Run them first.
+	mOnCleanup();
+
 	LLAtmosphere::cleanupClass();
 
 	//ditch LLVOAvatarSelf instance