Use dcp::file_to_string().

[dcpomatic.git] / src / lib / signaller.h

diff --git a/src/lib/signaller.h b/src/lib/signaller.h
index fa249078c1f1fd30609c3609a7a2776444199c0c..44650de871cbbd4109aa403d6e465ce7899c7b6b 100644 (file)
--- a/src/lib/signaller.h
+++ b/src/lib/signaller.h
@@ -1,37 +1,35 @@
 /*
-    Copyright (C) 2015 Carl Hetherington <cth@carlh.net>
+    Copyright (C) 2015-2021 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/>.
 
 */
 
+
 #ifndef DCPOMATIC_SIGNALLER_H
 #define DCPOMATIC_SIGNALLER_H
 
+
 #include "signal_manager.h"
 #include <boost/thread/mutex.hpp>
-#include <boost/signals2.hpp>
+
 
 class WrapperBase
 {
 public:
-       WrapperBase ()
-               : _valid (true)
-               , _finished (false)
-       {}
-
        virtual ~WrapperBase () {}
 
        /* Can be called from any thread */
@@ -42,17 +40,28 @@ 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;
        }
 
 protected:
        /* Protect _valid and _finished */
        mutable boost::mutex _mutex;
-       bool _valid;
-       bool _finished;
+       bool _valid = true;
+       bool _finished = false;
 };
 
+
 /** Helper class to manage lifetime of signals, specifically to address
  *  the problem where an object containing a signal is deleted before
  *  its signal is emitted.
@@ -61,7 +70,7 @@ template <class T>
 class Wrapper : public WrapperBase
 {
 public:
-       Wrapper (T signal)
+       explicit Wrapper (T signal)
                : _signal (signal)
        {
 
@@ -81,6 +90,7 @@ private:
        T _signal;
 };
 
+
 /** Parent for any class which needs to raise cross-thread signals (from non-UI
  *  to UI).  Subclasses should call, e.g. emit (boost::bind (boost::ref (MySignal), foo, bar));
  */
@@ -90,8 +100,8 @@ public:
        /* Can be called from any thread */
        virtual ~Signaller () {
                boost::mutex::scoped_lock lm (_signaller_mutex);
-               for (std::list<WrapperBase*>::iterator i = _wrappers.begin(); i != _wrappers.end(); ++i) {
-                       (*i)->invalidate ();
+               for (auto i: _wrappers) {
+                       i->invalidate();
                }
        }
 
@@ -99,17 +109,17 @@ public:
        template <class T>
        void emit (T signal)
        {
-               Wrapper<T>* w = new Wrapper<T> (signal);
+               auto w = new Wrapper<T> (signal);
                if (signal_manager) {
-                       signal_manager->emit (boost::bind (&Wrapper<T>::signal, w));
+                       signal_manager->emit (boost::bind(&Wrapper<T>::signal, w));
                }
 
                boost::mutex::scoped_lock lm (_signaller_mutex);
 
                /* Clean up finished Wrappers */
-               std::list<WrapperBase*>::iterator i = _wrappers.begin ();
+               auto i = _wrappers.begin ();
                while (i != _wrappers.end ()) {
-                       std::list<WrapperBase*>::iterator tmp = i;
+                       auto tmp = i;
                        ++tmp;
                        if ((*i)->finished ()) {
                                delete *i;
@@ -128,4 +138,5 @@ private:
        std::list<WrapperBase*> _wrappers;
 };
 
+
 #endif