Fix nasty race in dcpomatic_create.

diff --git a/src/lib/job.cc b/src/lib/job.cc
index 76976df322c1c3778bcac915709ea39a871f5d68..db9a9b215bdf74f3a6153dc7629516131ae00551 100644 (file)
--- a/src/lib/job.cc
+++ b/src/lib/job.cc
@@ -186,22 +186,33 @@ Job::paused () const
 void
 Job::set_state (State s)
 {
-       bool finished = false;
+       bool const finished = (s == FINISHED_OK || s == FINISHED_ERROR || s == FINISHED_CANCELLED);
        
+       /* Do this first, so that we handle things that should happen on finish before the
+        * job is actually marked as such.  This is important for callers that do:
+        *
+        * while (JobManager::work_to_do ()) {
+        *   ui_signaller->ui_idle ();
+        * }
+        *
+        * as otherwise this loop can finish before the Finished handler has been executed
+        * (job finishes, calls set_state(), this sets the state and sets a pending signal
+        * for Finished, but this is never called as a ui_idle() never happens as work_to_do()
+        * is now false).
+        */
+       if (finished && ui_signaller) {
+               ui_signaller->emit (boost::bind (boost::ref (Finished)));
+       }
+
        {
                boost::mutex::scoped_lock lm (_state_mutex);
                _state = s;
 
-               if (_state == FINISHED_OK || _state == FINISHED_ERROR || _state == FINISHED_CANCELLED) {
+               if (finished) {
                        _ran_for = elapsed_time ();
-                       finished = true;
                        _sub_name.clear ();
                }
        }
-
-       if (finished && ui_signaller) {
-               ui_signaller->emit (boost::bind (boost::ref (Finished)));
-       }
 }
 
 /** @return Time (in seconds) that this sub-job has been running */