X-Git-Url: https://main.carlh.net/gitweb/?a=blobdiff_plain;f=src%2Flib%2Fsignaller.h;h=b67a639173cf3e4a5547568bf17797c266f0b761;hb=bcc4e2f7dc4cd5658e199ddacb7202b00ec72cf1;hp=13474ee91baa3eac4e9c7d98042e29f17f68f0aa;hpb=dd8a7d1bbb8f2afb1b98d2be856ff0a9920e180d;p=dcpomatic.git

diff --git a/src/lib/signaller.h b/src/lib/signaller.h
index 13474ee91..b67a63917 100644
--- a/src/lib/signaller.h
+++ b/src/lib/signaller.h
@@ -1,19 +1,20 @@
 /*
     Copyright (C) 2015 Carl Hetherington <cth@carlh.net>
 
-    This program is free software; you can redistribute it and/or modify
+    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.
 
-    This program is distributed in the hope that it will be useful,
+    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 this program; if not, write to the Free Software
-    Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+    along with DCP-o-matic.  If not, see <http://www.gnu.org/licenses/>.
 
 */
 
@@ -41,7 +42,17 @@ public:
 	}
 
 	bool finished () const {
-		boost::mutex::scoped_lock lm (_mutex);
+		boost::mutex::scoped_lock lm (_mutex, boost::try_to_lock);
+		if (!lm) {
+			/* It's possible that emission of this
+			   wrapper's signal causes another signal to
+			   be emitted, which causes finished() on this
+			   wrapper to be called (by Signaller::emit).
+			   In this case, just say that the wrapper is
+			   not yet finished.
+			*/
+			return false;
+		}
 		return _finished;
 	}
 
@@ -60,7 +71,7 @@ template <class T>
 class Wrapper : public WrapperBase
 {
 public:
-	Wrapper (T signal)
+	explicit Wrapper (T signal)
 		: _signal (signal)
 	{