From 07ce0f0133a257f845423d11e37cb522c6fb1dcf Mon Sep 17 00:00:00 2001
From: Thomas Harte <thomas.harte@gmail.com>
Date: Thu, 7 Jul 2022 16:56:10 -0400
Subject: [PATCH] Attempt safe shutdown.

---
 Concurrency/AsyncUpdater.hpp                     | 12 +++++++++---
 OSBindings/Mac/Clock Signal/Machine/CSMachine.mm | 12 +++++++++---
 2 files changed, 18 insertions(+), 6 deletions(-)

diff --git a/Concurrency/AsyncUpdater.hpp b/Concurrency/AsyncUpdater.hpp
index 74e1fd334..12b937895 100644
--- a/Concurrency/AsyncUpdater.hpp
+++ b/Concurrency/AsyncUpdater.hpp
@@ -62,10 +62,16 @@ template <typename Performer> class AsyncUpdater {
 			condition_.notify_all();
 		}
 
+		void stop() {
+			if(performer_thread_.joinable()) {
+				should_quit = true;
+				update([] {});
+				performer_thread_.join();
+			}
+		}
+
 		~AsyncUpdater() {
-			should_quit = true;
-			update([] {});
-			performer_thread_.join();
+			stop();
 		}
 
 		// The object that will actually receive time advances.
diff --git a/OSBindings/Mac/Clock Signal/Machine/CSMachine.mm b/OSBindings/Mac/Clock Signal/Machine/CSMachine.mm
index ef588b7c2..bb66f3461 100644
--- a/OSBindings/Mac/Clock Signal/Machine/CSMachine.mm	
+++ b/OSBindings/Mac/Clock Signal/Machine/CSMachine.mm	
@@ -677,7 +677,6 @@ struct ActivityObserver: public Activity::Observer {
 #pragma mark - Timer
 
 - (void)audioQueueIsRunningDry:(nonnull CSAudioQueue *)audioQueue {
-	// TODO: Make audio flushes overt, and do one here.
 	updater.update([self] {
 		updater.performer.machine->flush_output();
 	});
@@ -692,6 +691,8 @@ struct ActivityObserver: public Activity::Observer {
 		});
 	});
 
+	// TODO: restory sync locking; see below.
+
 	// First order of business: grab a timestamp.
 /*	const auto timeNow = Time::nanos_now();
 
@@ -724,6 +725,10 @@ struct ActivityObserver: public Activity::Observer {
 #define TICKS	120
 
 - (void)start {
+//	_timer = [[CSHighPrecisionTimer alloc] initWithTask:^{
+//		updater.update([] {});
+//	} interval:uint64_t(1000000000) / uint64_t(TICKS)];
+
 //	updater.performer.machine = _machine->timed_machine();
 /*	__block auto lastTime = Time::nanos_now();
 
@@ -805,8 +810,9 @@ struct ActivityObserver: public Activity::Observer {
 #undef TICKS
 
 - (void)stop {
-	[_timer invalidate];
-	_timer = nil;
+	updater.stop();
+//	[_timer invalidate];
+//	_timer = nil;
 }
 
 + (BOOL)attemptInstallROM:(NSURL *)url {