Merge remote-tracking branch 'origin/main' into v2.17.x

3 files changed, 38 insertions, 0 deletions

diff --git a/src/lib/j2k_encoder.cc b/src/lib/j2k_encoder.cc
index 094e104ef..0b50bcd5a 100644
--- a/src/lib/j2k_encoder.cc
+++ b/src/lib/j2k_encoder.cc
@@ -108,6 +108,16 @@ J2KEncoder::~J2KEncoder ()
 {
 	_server_found_connection.disconnect();
 
+	/* One of our encoder threads may be waiting on Writer::write() to return, if that method
+	 * is blocked with the writer queue full waiting for _full_condition.  In that case, the
+	 * attempt to terminate the encoder threads below (in terminate_threads()) will fail because
+	 * the encoder thread waiting for ::write() will have interruption disabled.
+	 *
+	 * To work around that, make the writer into a zombie to unblock any pending write()s and
+	 * not block on any future ones.
+	 */
+	_writer.zombify();
+
 	terminate_threads();
 
 #ifdef DCPOMATIC_GROK
@@ -153,6 +163,8 @@ J2KEncoder::pause()
 	}
 	return;
 
+	/* XXX; the same problem may occur here as in the destructor, perhaps? */
+
 	terminate_threads ();
 
 	/* Something might have been thrown during terminate_threads */
diff --git a/src/lib/writer.cc b/src/lib/writer.cc
index 3dd22718f..c0b083ff0 100644
--- a/src/lib/writer.cc
+++ b/src/lib/writer.cc
@@ -146,6 +146,10 @@ Writer::write (shared_ptr<const Data> encoded, Frame frame, Eyes eyes)
 {
 	boost::mutex::scoped_lock lock (_state_mutex);
 
+	if (_zombie) {
+		return;
+	}
+
 	while (_queued_full_in_memory > _maximum_frames_in_memory) {
 		/* There are too many full frames in memory; wake the main writer thread and
 		   wait until it sorts everything out */
@@ -382,6 +386,9 @@ try
 	while (true)
 	{
 		boost::mutex::scoped_lock lock (_state_mutex);
+		if (_zombie) {
+			return;
+		}
 
 		while (true) {
 
@@ -1047,3 +1054,17 @@ Writer::write_hanging_text (ReelWriter& reel)
 	}
 	_hanging_texts = new_hanging_texts;
 }
+
+
+/** Set the writer so that it has no queue and drops any pending or future requests to write images */
+void
+Writer::zombify()
+{
+	boost::mutex::scoped_lock lock(_state_mutex);
+
+	_queue.clear();
+	_queued_full_in_memory = 0;
+	_zombie = true;
+	_full_condition.notify_all();
+}
+
diff --git a/src/lib/writer.h b/src/lib/writer.h
index 1dd88d8a9..f9ec0b88c 100644
--- a/src/lib/writer.h
+++ b/src/lib/writer.h
@@ -35,6 +35,7 @@
 #include "font_id_map.h"
 #include "player_text.h"
 #include "text_type.h"
+#include "types.h"
 #include "weak_film.h"
 #include <dcp/atmos_frame.h>
 #include <dcp/frame_info.h>
@@ -129,6 +130,8 @@ public:
 
 	void set_encoder_threads (int threads);
 
+	void zombify();
+
 private:
 	friend struct ::writer_disambiguate_font_ids1;
 	friend struct ::writer_disambiguate_font_ids2;
@@ -231,6 +234,8 @@ private:
 	};
 
 	std::vector<HangingText> _hanging_texts;
+
+	bool _zombie = false;
 };