From bd23f55d8cd73adda823d0a2fcabc129b8845a81 Mon Sep 17 00:00:00 2001
From: Carl Hetherington <cth@carlh.net>
Date: Mon, 17 Aug 2020 07:58:04 +0000
Subject: [PATCH] Report more detailed errors when the butler dies.

---
 src/lib/butler.cc         | 40 +++++++++++++++++++++++++++++++++++----
 src/lib/butler.h          | 21 ++++++++++++++++----
 src/lib/ffmpeg_encoder.cc |  2 +-
 src/wx/film_viewer.cc     |  5 ++++-
 4 files changed, 58 insertions(+), 10 deletions(-)

diff --git a/src/lib/butler.cc b/src/lib/butler.cc
index ab3e9b94e..76193a1ae 100644
--- a/src/lib/butler.cc
+++ b/src/lib/butler.cc
@@ -1,5 +1,5 @@
 /*
-    Copyright (C) 2016-2018 Carl Hetherington <cth@carlh.net>
+    Copyright (C) 2016-2020 Carl Hetherington <cth@carlh.net>
 
     This file is part of DCP-o-matic.
 
@@ -30,6 +30,7 @@
 #include <boost/shared_ptr.hpp>
 
 using std::cout;
+using std::exception;
 using std::pair;
 using std::make_pair;
 using std::string;
@@ -208,6 +209,12 @@ try
 	boost::mutex::scoped_lock lm (_mutex);
 	_finished = true;
 	_arrived.notify_all ();
+} catch (exception& e) {
+	store_current ();
+	boost::mutex::scoped_lock lm (_mutex);
+	_died = true;
+	_died_message = e.what();
+	_arrived.notify_all ();
 } catch (...) {
 	store_current ();
 	boost::mutex::scoped_lock lm (_mutex);
@@ -222,7 +229,7 @@ Butler::get_video (Error* e)
 
 	if (_suspended) {
 		if (e) {
-			*e = AGAIN;
+			e->code = Error::AGAIN;
 		}
 		return make_pair(shared_ptr<PlayerVideo>(), DCPTime());
 	}
@@ -233,8 +240,9 @@ Butler::get_video (Error* e)
 	}
 
 	if (_video.empty()) {
-		if (e) {
-			*e = _died ? DIED : NONE;
+		if (e && _died) {
+			e->code = Error::DIED;
+			e->message = _died_message;
 		}
 		return make_pair(shared_ptr<PlayerVideo>(), DCPTime());
 	}
@@ -292,6 +300,13 @@ try
 		LOG_TIMING("finish-prepare in %1", thread_id());
 	}
 }
+catch (exception& e)
+{
+	store_current ();
+	boost::mutex::scoped_lock lm (_mutex);
+	_died = true;
+	_died_message = e.what();
+}
 catch (...)
 {
 	store_current ();
@@ -404,3 +419,20 @@ Butler::text (PlayerText pt, TextType type, optional<DCPTextTrack> track, DCPTim
 	boost::mutex::scoped_lock lm2 (_buffers_mutex);
 	_closed_caption.put (pt, *track, period);
 }
+
+
+string
+Butler::Error::summary () const
+{
+	switch (code)
+	{
+		case Error::NONE:
+			return "No error registered";
+		case Error::AGAIN:
+			return "Butler not ready";
+		case Error::DIED:
+			return String::compose("Butler died (%1)", message);
+	}
+
+	return "";
+}
diff --git a/src/lib/butler.h b/src/lib/butler.h
index 4d4fa4a09..a62eb0525 100644
--- a/src/lib/butler.h
+++ b/src/lib/butler.h
@@ -49,10 +49,22 @@ public:
 
 	void seek (DCPTime position, bool accurate);
 
-	enum Error {
-		NONE,
-		AGAIN,
-		DIED
+	class Error {
+	public:
+		enum Code {
+			NONE,
+			AGAIN,
+			DIED
+		};
+
+		Error ()
+			: code(NONE)
+		{}
+
+		Code code;
+		std::string message;
+
+		std::string summary () const;
 	};
 
 	std::pair<boost::shared_ptr<PlayerVideo>, DCPTime> get_video (Error* e = 0);
@@ -99,6 +111,7 @@ private:
 	int _suspended;
 	bool _finished;
 	bool _died;
+	std::string _died_message;
 	bool _stop_thread;
 
 	AudioMapping _audio_mapping;
diff --git a/src/lib/ffmpeg_encoder.cc b/src/lib/ffmpeg_encoder.cc
index 25ad4a54c..8ab56a592 100644
--- a/src/lib/ffmpeg_encoder.cc
+++ b/src/lib/ffmpeg_encoder.cc
@@ -155,7 +155,7 @@ FFmpegEncoder::go ()
 			Butler::Error e;
 			pair<shared_ptr<PlayerVideo>, DCPTime> v = _butler->get_video (&e);
 			if (!v.first) {
-				throw ProgrammingError(__FILE__, __LINE__, String::compose("butler returned no video; error was %1", static_cast<int>(e)));
+				throw ProgrammingError(__FILE__, __LINE__, String::compose("butler returned no video; error was %1", e.summary()));
 			}
 			shared_ptr<FFmpegFileEncoder> fe = encoder->get (v.first->eyes());
 			if (fe) {
diff --git a/src/wx/film_viewer.cc b/src/wx/film_viewer.cc
index f68b21309..6ae582366 100644
--- a/src/wx/film_viewer.cc
+++ b/src/wx/film_viewer.cc
@@ -239,7 +239,10 @@ FilmViewer::get ()
 	do {
 		Butler::Error e;
 		_player_video = _butler->get_video (&e);
-		if (!_player_video.first && e == Butler::AGAIN) {
+		if (e.code == Butler::Error::DIED) {
+			LOG_ERROR ("Butler died with %1", e.message);
+		}
+		if (!_player_video.first && e.code == Butler::Error::Code::AGAIN) {
 			signal_manager->when_idle (boost::bind(&FilmViewer::get, this));
 			return;
 		}
-- 
2.30.2