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, 13 insertions, 10 deletions

diff --git a/indra/newview/llstartup.cpp b/indra/newview/llstartup.cpp
index adfa1b0c10..d8e68dbc1e 100644
--- a/indra/newview/llstartup.cpp
+++ b/indra/newview/llstartup.cpp
@@ -259,7 +259,6 @@ const F32 STATE_AGENT_WAIT_TIMEOUT = 240; //seconds
 std::unique_ptr<LLEventPump> LLStartUp::sStateWatcher(new LLEventStream("StartupState"));
 std::unique_ptr<LLStartupListener> LLStartUp::sListener(new LLStartupListener());
 std::unique_ptr<LLViewerStats::PhaseMap> LLStartUp::sPhases(new LLViewerStats::PhaseMap);
-std::unique_ptr<LL::ThreadPool> gGeneralThreadPool;
 
 //
 // local function declaration
@@ -1495,15 +1494,19 @@ bool idle_startup()
 		display_startup();
 
 		// start up the ThreadPool we'll use for textures et al.
-		LLSD poolSizes{ gSavedSettings.getLLSD("ThreadPoolSizes") };
-		LLSD sizeSpec{ poolSizes["General"] };
-		LLSD::Integer poolSize{ sizeSpec.isInteger()? sizeSpec.asInteger() : 3 };
-		LL_DEBUGS("ThreadPool") << "Instantiating General pool with "
-								<< poolSize << " threads" << LL_ENDL;
-		// We don't want anyone, especially the main thread, to have to block
-		// due to this ThreadPool being full.
-		gGeneralThreadPool.reset(new LL::ThreadPool("General", poolSize, 1024*1024));
-		gGeneralThreadPool->start();
+		{
+			LLSD poolSizes{ gSavedSettings.getLLSD("ThreadPoolSizes") };
+			LLSD sizeSpec{ poolSizes["General"] };
+			LLSD::Integer poolSize{ sizeSpec.isInteger()? sizeSpec.asInteger() : 3 };
+			LL_DEBUGS("ThreadPool") << "Instantiating General pool with "
+									<< poolSize << " threads" << LL_ENDL;
+			// We don't want anyone, especially the main thread, to have to block
+			// due to this ThreadPool being full.
+			auto pool = new LL::ThreadPool("General", poolSize, 1024*1024);
+			pool->start();
+			// Once we start shutting down, destroy this ThreadPool.
+			LLAppViewer::instance()->onCleanup([pool](){ delete pool; });
+		}
 
 		// Initialize global class data needed for surfaces (i.e. textures)
 		LL_DEBUGS("AppInit") << "Initializing sky..." << LL_ENDL;