From 75ec5ee87d04ff001492531f9b474c7447ffd731 Mon Sep 17 00:00:00 2001
From: Robin Gareus <robin@gareus.org>
Date: Tue, 1 Mar 2022 18:20:40 +0100
Subject: [PATCH] Terminate Peak file threads at exit

---
 libs/ardour/ardour/source_factory.h |  5 +++++
 libs/ardour/globals.cc              |  1 +
 libs/ardour/source_factory.cc       | 33 +++++++++++++++++++++++++----
 3 files changed, 35 insertions(+), 4 deletions(-)

diff --git a/libs/ardour/ardour/source_factory.h b/libs/ardour/ardour/source_factory.h
index 473b2c4851..5d4f69e648 100644
--- a/libs/ardour/ardour/source_factory.h
+++ b/libs/ardour/ardour/source_factory.h
@@ -24,6 +24,7 @@
 #include <stdint.h>
 #include <string>
 
+#include "pbd/pthread_utils.h"
 #include "ardour/source.h"
 
 class XMLNode;
@@ -38,6 +39,7 @@ class LIBARDOUR_API SourceFactory
 {
 public:
 	static void init ();
+	static void terminate ();
 
 	static PBD::Signal1<void, boost::shared_ptr<Source>> SourceCreated;
 
@@ -51,6 +53,9 @@ public:
 	static Glib::Threads::Cond  PeaksToBuild;
 	static Glib::Threads::Mutex peak_building_lock;
 
+	static bool                      peak_thread_run;
+	static std::vector<PBD::Thread*> peak_thread_pool;
+
 	static std::list<boost::weak_ptr<AudioSource>> files_with_peaks;
 
 	static int peak_work_queue_length ();
diff --git a/libs/ardour/globals.cc b/libs/ardour/globals.cc
index 2a49c0b7a6..d3220876d4 100644
--- a/libs/ardour/globals.cc
+++ b/libs/ardour/globals.cc
@@ -739,6 +739,7 @@ ARDOUR::cleanup ()
 	delete TriggerBox::worker;
 
 	Analyser::terminate ();
+	SourceFactory::terminate ();
 
 	release_dma_latency ();
 	config_connection.disconnect ();
diff --git a/libs/ardour/source_factory.cc b/libs/ardour/source_factory.cc
index 3944eda0c8..20eed4a516 100644
--- a/libs/ardour/source_factory.cc
+++ b/libs/ardour/source_factory.cc
@@ -26,7 +26,6 @@
 
 #include "pbd/convert.h"
 #include "pbd/error.h"
-#include "pbd/pthread_utils.h"
 
 #include "ardour/audio_playlist_source.h"
 #include "ardour/audioplaylist.h"
@@ -55,6 +54,8 @@ PBD::Signal1<void, boost::shared_ptr<Source>> SourceFactory::SourceCreated;
 Glib::Threads::Cond                           SourceFactory::PeaksToBuild;
 Glib::Threads::Mutex                          SourceFactory::peak_building_lock;
 std::list<boost::weak_ptr<AudioSource>>       SourceFactory::files_with_peaks;
+std::vector<PBD::Thread*>                     SourceFactory::peak_thread_pool;
+bool                                          SourceFactory::peak_thread_run = false;
 
 static int active_threads = 0;
 
@@ -68,17 +69,24 @@ peak_thread_work ()
 		SourceFactory::peak_building_lock.lock ();
 
 	wait:
-		if (SourceFactory::files_with_peaks.empty ()) {
+		if (SourceFactory::files_with_peaks.empty () && SourceFactory::peak_thread_run) {
 			SourceFactory::PeaksToBuild.wait (SourceFactory::peak_building_lock);
 		}
 
+		if (!SourceFactory::peak_thread_run) {
+			SourceFactory::peak_building_lock.unlock ();
+			return;
+		}
+
 		if (SourceFactory::files_with_peaks.empty ()) {
 			goto wait;
 		}
 
 		boost::shared_ptr<AudioSource> as (SourceFactory::files_with_peaks.front ().lock ());
 		SourceFactory::files_with_peaks.pop_front ();
-		++active_threads;
+		if (as) {
+			++active_threads;
+		}
 		SourceFactory::peak_building_lock.unlock ();
 
 		if (!as) {
@@ -103,8 +111,25 @@ SourceFactory::peak_work_queue_length ()
 void
 SourceFactory::init ()
 {
+	if (peak_thread_run) {
+		return;
+	}
+	peak_thread_run = true;
 	for (int n = 0; n < 2; ++n) {
-		PBD::Thread::create (&peak_thread_work);
+		peak_thread_pool.push_back (PBD::Thread::create (&peak_thread_work));
+	}
+}
+
+void
+SourceFactory::terminate ()
+{
+	if (!peak_thread_run) {
+		return;
+	}
+	peak_thread_run = false;
+	PeaksToBuild.broadcast ();
+	for (auto& t : peak_thread_pool) {
+		t->join ();
 	}
 }