From 6abf2fdd53b14608561fcc1900507daea5b79fb7 Mon Sep 17 00:00:00 2001
From: Carl Hetherington <cth@carlh.net>
Date: Mon, 17 Aug 2020 15:44:58 +0200
Subject: [PATCH] Report better errors when the butler dies.

Adapted from d23f55d8cd73adda823d0a2fcabc129b8845a81 in master.
---
 src/lib/butler.cc         | 41 +++++++++++++++++++++++++++++++++++----
 src/lib/butler.h          | 23 +++++++++++++++++-----
 src/lib/ffmpeg_encoder.cc |  2 +-
 src/wx/video_view.cc      |  6 +++++-
 4 files changed, 61 insertions(+), 11 deletions(-)

diff --git a/src/lib/butler.cc b/src/lib/butler.cc
index df2358086..33938ece4 100644
--- a/src/lib/butler.cc
+++ b/src/lib/butler.cc
@@ -208,6 +208,12 @@ try
 	boost::mutex::scoped_lock lm (_mutex);
 	_finished = true;
 	_arrived.notify_all ();
+} catch (std::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);
@@ -226,7 +232,7 @@ Butler::get_video (bool blocking, Error* e)
 
 	if (_suspended || (_video.empty() && !blocking)) {
 		if (e) {
-			*e = AGAIN;
+			e->code = Error::AGAIN;
 		}
 		return make_pair(shared_ptr<PlayerVideo>(), DCPTime());
 	}
@@ -239,11 +245,12 @@ Butler::get_video (bool blocking, Error* e)
 	if (_video.empty()) {
 		if (e) {
 			if (_died) {
-				*e = DIED;
+				e->code = Error::DIED;
+				e->message = _died_message;
 			} else if (_finished) {
-				*e = FINISHED;
+				e->code = Error::FINISHED;
 			} else {
-				*e = NONE;
+				e->code = Error::NONE;
 			}
 		}
 		return make_pair(shared_ptr<PlayerVideo>(), DCPTime());
@@ -299,6 +306,13 @@ try
 		LOG_TIMING("finish-prepare in %1", thread_id());
 	}
 }
+catch (std::exception& e)
+{
+	store_current ();
+	boost::mutex::scoped_lock lm (_mutex);
+	_died = true;
+	_died_message = e.what ();
+}
 catch (...)
 {
 	store_current ();
@@ -406,3 +420,22 @@ Butler::text (PlayerText pt, TextType type, optional<DCPTextTrack> track, DCPTim
 
 	_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);
+		case Error::FINISHED:
+			return "Butler finished";
+	}
+
+	return "";
+}
+
diff --git a/src/lib/butler.h b/src/lib/butler.h
index 6263d6143..e13843c90 100644
--- a/src/lib/butler.h
+++ b/src/lib/butler.h
@@ -49,11 +49,23 @@ public:
 
 	void seek (dcpomatic::DCPTime position, bool accurate);
 
-	enum Error {
-		NONE,
-		AGAIN,
-		DIED,
-		FINISHED
+	class Error {
+	public:
+		enum Code{
+			NONE,
+			AGAIN,
+			DIED,
+			FINISHED
+		};
+
+		Error()
+			: code (NONE)
+		{}
+
+		Code code;
+		std::string message;
+
+		std::string summary () const;
 	};
 
 	std::pair<boost::shared_ptr<PlayerVideo>, dcpomatic::DCPTime> get_video (bool blocking, Error* e = 0);
@@ -94,6 +106,7 @@ 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 cf91a9fae..cd03c7b93 100644
--- a/src/lib/ffmpeg_encoder.cc
+++ b/src/lib/ffmpeg_encoder.cc
@@ -174,7 +174,7 @@ FFmpegEncoder::go ()
 			pair<shared_ptr<PlayerVideo>, DCPTime> v = _butler->get_video (true, &e);
 			_butler->rethrow ();
 			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/video_view.cc b/src/wx/video_view.cc
index b0e16737c..7eea4b786 100644
--- a/src/wx/video_view.cc
+++ b/src/wx/video_view.cc
@@ -22,6 +22,7 @@
 #include "wx_util.h"
 #include "film_viewer.h"
 #include "lib/butler.h"
+#include "lib/dcpomatic_log.h"
 #include <boost/optional.hpp>
 
 using std::pair;
@@ -74,7 +75,10 @@ VideoView::get_next_frame (bool non_blocking)
 	do {
 		Butler::Error e;
 		pair<shared_ptr<PlayerVideo>, dcpomatic::DCPTime> pv = butler->get_video (!non_blocking, &e);
-		if (!pv.first && e == Butler::AGAIN) {
+		if (e.code == Butler::Error::DIED) {
+			LOG_ERROR ("Butler died with %1", e.summary());
+		}
+		if (!pv.first && e.code == Butler::Error::AGAIN) {
 			return false;
 		}
 		_player_video = pv;
-- 
2.30.2