This AtomicityChecker was introduced a long time ago for reasons

that are unclear.

This commit removes it because it was causing a bug whereby the
_suspended count on Butler would not go back down to 0 due to signals
being blocked by the AtomicityChecker.

I can see two possibilities:

1. AtomicityChecker is a band-aid for some deeper problem, in which
case other bugs will become apparent.  Perhaps it relates to signals
being sent before the butler/player/playlist are connected to content.

2. AtomicityChecker was correct but was not identifiying signals
from different pieces of content correctly; so the correct fix would
be to add the content pointer to the _checker.send() call and block
based also on that.

5 files changed, 3 insertions, 88 deletions

diff --git a/src/lib/atomicity_checker.cc b/src/lib/atomicity_checker.cc
deleted file mode 100644
index 922aa152a..000000000
--- a/src/lib/atomicity_checker.cc
+++ /dev/null
@@ -1,43 +0,0 @@
-/*
-    Copyright (C) 2018 Carl Hetherington <cth@carlh.net>
-
-    This file is part of DCP-o-matic.
-
-    DCP-o-matic is free software; you can redistribute it and/or modify
-    it under the terms of the GNU General Public License as published by
-    the Free Software Foundation; either version 2 of the License, or
-    (at your option) any later version.
-
-    DCP-o-matic is distributed in the hope that it will be useful,
-    but WITHOUT ANY WARRANTY; without even the implied warranty of
-    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
-    GNU General Public License for more details.
-
-    You should have received a copy of the GNU General Public License
-    along with DCP-o-matic.  If not, see <http://www.gnu.org/licenses/>.
-
-*/
-
-#include "atomicity_checker.h"
-#include "types.h"
-
-/** @return true if this change should be ignored */
-bool
-AtomicityChecker::send (ChangeType type, int property)
-{
-	boost::mutex::scoped_lock lm (_mutex);
-	switch (type) {
-	case CHANGE_TYPE_PENDING:
-		_await.insert (property);
-		return false;
-	case CHANGE_TYPE_DONE:
-	case CHANGE_TYPE_CANCELLED:
-		if (_await.find(property) != _await.end()) {
-			_await.erase (property);
-			return false;
-		}
-		return true;
-	}
-
-	return false;
-}
diff --git a/src/lib/atomicity_checker.h b/src/lib/atomicity_checker.h
deleted file mode 100644
index 5a47235ad..000000000
--- a/src/lib/atomicity_checker.h
+++ /dev/null
@@ -1,33 +0,0 @@
-/*
-    Copyright (C) 2018 Carl Hetherington <cth@carlh.net>
-
-    This file is part of DCP-o-matic.
-
-    DCP-o-matic is free software; you can redistribute it and/or modify
-    it under the terms of the GNU General Public License as published by
-    the Free Software Foundation; either version 2 of the License, or
-    (at your option) any later version.
-
-    DCP-o-matic is distributed in the hope that it will be useful,
-    but WITHOUT ANY WARRANTY; without even the implied warranty of
-    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
-    GNU General Public License for more details.
-
-    You should have received a copy of the GNU General Public License
-    along with DCP-o-matic.  If not, see <http://www.gnu.org/licenses/>.
-
-*/
-
-#include "types.h"
-#include <boost/thread/mutex.hpp>
-#include <set>
-
-class AtomicityChecker
-{
-public:
-	bool send (ChangeType type, int property);
-
-private:
-	boost::mutex _mutex;
-	std::set<int> _await;
-};
diff --git a/src/lib/playlist.cc b/src/lib/playlist.cc
index 48053bbf4..b96b0fbe0 100644
--- a/src/lib/playlist.cc
+++ b/src/lib/playlist.cc
@@ -70,13 +70,6 @@ Playlist::~Playlist ()
 void
 Playlist::content_change (weak_ptr<const Film> weak_film, ChangeType type, weak_ptr<Content> content, int property, bool frequent)
 {
-	/* Make sure we only hear about atomic changes (e.g. a PENDING always with the DONE/CANCELLED)
-	   Ignore any DONE/CANCELLED that arrives without a PENDING.
-	*/
-	if (_checker.send (type, property)) {
-		return;
-	}
-
 	shared_ptr<const Film> film = weak_film.lock ();
 	DCPOMATIC_ASSERT (film);
 
diff --git a/src/lib/playlist.h b/src/lib/playlist.h
index dc984aacf..51c13e33f 100644
--- a/src/lib/playlist.h
+++ b/src/lib/playlist.h
@@ -1,5 +1,5 @@
 /*
-    Copyright (C) 2013-2018 Carl Hetherington <cth@carlh.net>
+    Copyright (C) 2013-2020 Carl Hetherington <cth@carlh.net>
 
     This file is part of DCP-o-matic.
 
@@ -23,10 +23,10 @@
 
 #include "util.h"
 #include "frame_rate_change.h"
-#include "atomicity_checker.h"
 #include <libcxml/cxml.h>
 #include <boost/shared_ptr.hpp>
 #include <boost/signals2.hpp>
+#include <boost/thread.hpp>
 #include <list>
 
 class Film;
@@ -94,7 +94,6 @@ private:
 	bool _sequence;
 	bool _sequencing;
 	std::list<boost::signals2::connection> _content_connections;
-	AtomicityChecker _checker;
 };
 
 #endif
diff --git a/src/lib/wscript b/src/lib/wscript
index fb222fcf4..ad4dbd87d 100644
--- a/src/lib/wscript
+++ b/src/lib/wscript
@@ -1,5 +1,5 @@
 #
-#    Copyright (C) 2012-2015 Carl Hetherington <cth@carlh.net>
+#    Copyright (C) 2012-2020 Carl Hetherington <cth@carlh.net>
 #
 #    This file is part of DCP-o-matic.
 #
@@ -26,7 +26,6 @@ sources = """
           analyse_subtitles_job.cc
           analytics.cc
           atmos_mxf_content.cc
-          atomicity_checker.cc
           audio_analysis.cc
           audio_buffers.cc
           audio_content.cc