expand SessionEvent API to allow ::clear_events() to work correctly.

clear_events() must run in realtime context, which is likely to be asynchronous
with respect to the thread that calls it. So allow caller to pass in a functor
that will be executed (also in realtime context) after the clear is done.

Additionally, allow for a cross-thread callback to the event loop/thread which
initiated/allocated the clear event request so that it can flush its own pending
loop. This part probably isn't necessary but doesn't hurt and is a useful model.
The event would be placed back in the free list at the next event allocation
by the calling thread anyway.

diff --git a/libs/ardour/ardour/session_event.h b/libs/ardour/ardour/session_event.h
index 3f7fc6c092219861f4ccfd4da7b3055f1e158485..96145e7b295aee94ba80b73e7e72d9a56aa2daf3 100644 (file)
--- a/libs/ardour/ardour/session_event.h
+++ b/libs/ardour/ardour/session_event.h
@@ -111,16 +111,7 @@ public:
 
        boost::shared_ptr<Region> region;
 
-       SessionEvent (Type t, Action a, framepos_t when, framepos_t where, double spd, bool yn = false, bool yn2 = false, bool yn3 = false)
-               : type (t)
-               , action (a)
-               , action_frame (when)
-               , target_frame (where)
-               , speed (spd)
-               , yes_or_no (yn)
-               , second_yes_or_no (yn2)
-               , third_yes_or_no (yn3)
-               , event_loop (0) {}
+       SessionEvent (Type t, Action a, framepos_t when, framepos_t where, double spd, bool yn = false, bool yn2 = false, bool yn3 = false);
 
        void set_ptr (void* p) {
                ptr = p;
@@ -146,6 +137,8 @@ public:
        static void create_per_thread_pool (const std::string& n, uint32_t nitems);
        static void init_event_pool ();
 
+       CrossThreadPool* event_pool() const { return own_pool; }
+       
 private:
        static PerThreadPool* pool;
        CrossThreadPool* own_pool;
@@ -161,6 +154,7 @@ public:
 
        virtual void queue_event (SessionEvent *ev) = 0;
        void clear_events (SessionEvent::Type type);
+       void clear_events (SessionEvent::Type type, boost::function<void (void)> after);
 
 protected:
        RingBuffer<SessionEvent*> pending_events;

diff --git a/libs/ardour/session_events.cc b/libs/ardour/session_events.cc
index e529c1b94af13f746fb5b552eedb91ed9f70c478..92b9e88fa66740ed66c010762ff12bb924a1f1c2 100644 (file)
--- a/libs/ardour/session_events.cc
+++ b/libs/ardour/session_events.cc
@@ -52,15 +52,31 @@ SessionEvent::create_per_thread_pool (const std::string& name, uint32_t nitems)
        pool->create_per_thread_pool (name, sizeof (SessionEvent), nitems);
 }
 
+SessionEvent::SessionEvent (Type t, Action a, framepos_t when, framepos_t where, double spd, bool yn, bool yn2, bool yn3)
+       : type (t)
+       , action (a)
+       , action_frame (when)
+       , target_frame (where)
+       , speed (spd)
+       , yes_or_no (yn)
+       , second_yes_or_no (yn2)
+       , third_yes_or_no (yn3)
+       , event_loop (0)
+{
+       DEBUG_TRACE (DEBUG::SessionEvents, string_compose ("NEW SESSION EVENT, type = %1 action = %2\n", enum_2_string (type), enum_2_string (action)));
+}
+
 void *
 SessionEvent::operator new (size_t)
 {
        CrossThreadPool* p = pool->per_thread_pool ();
        SessionEvent* ev = static_cast<SessionEvent*> (p->alloc ());
-       DEBUG_TRACE (DEBUG::SessionEvents, string_compose ("%1 Allocating SessionEvent from %2 ev @ %3\n", pthread_name(), p->name(), ev));
+       DEBUG_TRACE (DEBUG::SessionEvents, string_compose ("%1 Allocating SessionEvent from %2 ev @ %3 pool size %4 free %5 used %6\n", pthread_name(), p->name(), ev,
+                                                          p->total(), p->available(), p->used()));
+                                                          
 #ifndef NDEBUG
        if (DEBUG::SessionEvents & PBD::debug_bits) {
-               stacktrace (cerr, 40);
+               // stacktrace (cerr, 40);
        }
 #endif
        ev->own_pool = p;
@@ -74,13 +90,13 @@ SessionEvent::operator delete (void *ptr, size_t /*size*/)
        SessionEvent* ev = static_cast<SessionEvent*> (ptr);
 
        DEBUG_TRACE (DEBUG::SessionEvents, string_compose (
-                            "%1 Deleting SessionEvent @ %2 ev thread pool = %3 ev pool = %4\n",
-                            pthread_name(), ev, p->name(), ev->own_pool->name()
+                            "%1 Deleting SessionEvent @ %2 type %3 action %4 ev thread pool = %5 ev pool = %6 size %7 free %8 used %9\n",
+                            pthread_name(), ev, enum_2_string (ev->type), enum_2_string (ev->action), p->name(), ev->own_pool->name(), ev->own_pool->total(), ev->own_pool->available(), ev->own_pool->used()
                             ));
 
 #ifndef NDEBUG
        if (DEBUG::SessionEvents & PBD::debug_bits) {
-               stacktrace (cerr, 40);
+               // stacktrace (cerr, 40);
        }
 #endif
 
@@ -88,6 +104,10 @@ SessionEvent::operator delete (void *ptr, size_t /*size*/)
                p->release (ptr);
        } else {
                ev->own_pool->push (ev);
+               DEBUG_TRACE (DEBUG::SessionEvents, string_compose ("%1 was wrong thread for this pool, pushed event onto pending list, will be deleted on next alloc from %2 pool size %3 free %4 used %5 pending %6\n",
+                                                                  pthread_name(), ev->own_pool->name(),
+                                                                  ev->own_pool->total(), ev->own_pool->available(), ev->own_pool->used(),
+                                                                  ev->own_pool->pending_size()));
        }
 }
 
@@ -119,6 +139,24 @@ SessionEventManager::clear_events (SessionEvent::Type type)
        queue_event (ev);
 }
 
+void
+SessionEventManager::clear_events (SessionEvent::Type type, boost::function<void (void)> after)
+{
+       SessionEvent* ev = new SessionEvent (type, SessionEvent::Clear, SessionEvent::Immediate, 0, 0);
+       ev->rt_slot = after;
+
+       /* in the calling thread, after the clear is complete, arrange to flush things from the event
+          pool pending list (i.e. to make sure they are really back in the free list and available
+          for future events).
+       */
+
+       ev->event_loop = PBD::EventLoop::get_event_loop_for_thread ();
+       if (ev->event_loop) {
+               ev->rt_return = boost::bind (&CrossThreadPool::flush_pending_with_ev, ev->event_pool(), _1);
+       }
+
+       queue_event (ev);
+}
 
 void
 SessionEventManager::dump_events () const
@@ -159,7 +197,14 @@ SessionEventManager::merge_event (SessionEvent* ev)
 
        case SessionEvent::Clear:
                _clear_event_type (ev->type);
-               delete ev;
+               /* run any additional realtime callback */
+               ev->rt_slot ();
+               if (ev->event_loop) {
+                       /* run non-realtime callback (in some other thread) */
+                       ev->event_loop->call_slot (MISSING_INVALIDATOR, boost::bind (ev->rt_return, ev));
+               } else {
+                       delete ev;
+               }
                return;
 
        case SessionEvent::Add: