Protect _threads with a mutex since it may be updated from

the GUI thread (via ServersChanged) or from the job thread
(via end ()).

diff --git a/src/lib/encoder.cc b/src/lib/encoder.cc
index b35f49a1b9460372d8cd1b458b40ad41edae8f1c..00e28e1ebabbdd235f7cd31d964fbab03bf3be17 100644 (file)
--- a/src/lib/encoder.cc
+++ b/src/lib/encoder.cc
@@ -83,7 +83,7 @@ Encoder::begin ()
 void
 Encoder::end ()
 {
-       boost::mutex::scoped_lock lock (_mutex);
+       boost::mutex::scoped_lock lock (_queue_mutex);
 
        LOG_GENERAL (N_("Clearing queue of %1"), _queue.size ());
 
@@ -172,14 +172,20 @@ Encoder::enqueue (shared_ptr<PlayerVideo> pv)
 {
        _waker.nudge ();
 
-       boost::mutex::scoped_lock lock (_mutex);
+       size_t threads = 0;
+       {
+               boost::mutex::scoped_lock threads_lock (_threads_mutex);
+               threads = _threads.size ();
+       }
+
+       boost::mutex::scoped_lock queue_lock (_queue_mutex);
 
        /* XXX: discard 3D here if required */
 
        /* Wait until the queue has gone down a bit */
-       while (_queue.size() >= _threads.size() * 2 && !_terminate) {
+       while (_queue.size() >= threads * 2 && !_terminate) {
                LOG_TIMING ("decoder-sleep queue=%1", _queue.size());
-               _full_condition.wait (lock);
+               _full_condition.wait (queue_lock);
                LOG_TIMING ("decoder-wake queue=%1", _queue.size());
        }
 
@@ -249,12 +255,14 @@ void
 Encoder::terminate_threads ()
 {
        {
-               boost::mutex::scoped_lock lock (_mutex);
+               boost::mutex::scoped_lock queue_lock (_queue_mutex);
                _terminate = true;
                _full_condition.notify_all ();
                _empty_condition.notify_all ();
        }
 
+       boost::mutex::scoped_lock threads_lock (_threads_mutex);
+
        for (list<boost::thread *>::iterator i = _threads.begin(); i != _threads.end(); ++i) {
                if ((*i)->joinable ()) {
                        (*i)->join ();
@@ -285,7 +293,7 @@ try
        while (true) {
 
                LOG_TIMING ("encoder-sleep thread=%1", boost::this_thread::get_id());
-               boost::mutex::scoped_lock lock (_mutex);
+               boost::mutex::scoped_lock lock (_queue_mutex);
                while (_queue.empty () && !_terminate) {
                        _empty_condition.wait (lock);
                }
@@ -367,6 +375,8 @@ Encoder::servers_list_changed ()
 
        /* XXX: could re-use threads */
 
+       boost::mutex::scoped_lock lm (_threads_mutex);
+
        if (!Config::instance()->only_servers_encode ()) {
                for (int i = 0; i < Config::instance()->num_local_encoding_threads (); ++i) {
                        _threads.push_back (new boost::thread (boost::bind (&Encoder::encoder_thread, this, optional<ServerDescription> ())));

diff --git a/src/lib/encoder.h b/src/lib/encoder.h
index fbae07a9a8ebe7cd2a4b20b9f656239631158e6c..9b1b528bbd305c9c203f4682158127346110b7c9 100644 (file)
--- a/src/lib/encoder.h
+++ b/src/lib/encoder.h
@@ -82,7 +82,7 @@ private:
        boost::shared_ptr<const Film> _film;
        boost::weak_ptr<Job> _job;
 
-       /** Mutex for _time_history and _last_frame */
+       /** Mutex for _time_history and _video_frames_enqueued */
        mutable boost::mutex _state_mutex;
        /** List of the times of completion of the last _history_size frames;
            first is the most recently completed.
@@ -90,16 +90,17 @@ private:
        std::list<struct timeval> _time_history;
        /** Number of frames that we should keep history for */
        static int const _history_size;
-
        /** Number of video frames enqueued so far */
        int _video_frames_enqueued;
        bool _left_done;
        bool _right_done;
 
-       bool _terminate;
-       std::list<boost::shared_ptr<DCPVideo> > _queue;
+       boost::atomic<bool> _terminate;
+       /** Mutex for _threads */
+       mutable boost::mutex _threads_mutex;
        std::list<boost::thread *> _threads;
-       mutable boost::mutex _mutex;
+       mutable boost::mutex _queue_mutex;
+       std::list<boost::shared_ptr<DCPVideo> > _queue;
        /** condition to manage thread wakeups when we have nothing to do */
        boost::condition _empty_condition;
        /** condition to manage thread wakeups when we have too much to do */